This is our response to a concern raised by a reader regarding the estimates and credible intervals of those numbers needed to treat to harm presented in our article titled “Extended treatment of venous thromboembolism: a systematic review and network meta-analysis.”
First, we confirm that data published in the Journal are valid and correct.
We also like to thank the reader to point it out as a number needed (either for benefit or harm) derived from an effect estimate that crosses the unity has been intuitively challenging to visualize (Hutton JL. Br J Haematol. 2009;146:27-30). Because it is given by the reciprocal of the absolute risk difference, a number needed can never include zero but straddles plus and minus infinity ∞ when the absolute risk difference include zero. By the frequentist approach based on inverting the confidence interval of the absolute risk difference, it represents that the number needed encompasses two disjoint regions: one from upper confidence interval to plus ∞ and the other from lower confidence interval to minus ∞ (Altman DG. BMJ. 1998;317:1309-12). Some had argued that for those non-significant results, a number needed should be presented as a single number without its confidence interval as it includes the possibility of no benefit or harm (McQuay HJ. Ann Intern Med. 1997;126:712-20). Other had suggested that it should not be reported when being non-significant (McAlister FA. CMAJ. 2008;179:549-53).
This is our response to a concern raised by a reader regarding the estimates and credible intervals of those numbers needed to treat to harm presented in our article titled “Extended treatment of venous thromboembolism: a systematic review and network meta-analysis.”
First, we confirm that data published in the Journal are valid and correct.
We also like to thank the reader to point it out as a number needed (either for benefit or harm) derived from an effect estimate that crosses the unity has been intuitively challenging to visualize (Hutton JL. Br J Haematol. 2009;146:27-30). Because it is given by the reciprocal of the absolute risk difference, a number needed can never include zero but straddles plus and minus infinity ∞ when the absolute risk difference include zero. By the frequentist approach based on inverting the confidence interval of the absolute risk difference, it represents that the number needed encompasses two disjoint regions: one from upper confidence interval to plus ∞ and the other from lower confidence interval to minus ∞ (Altman DG. BMJ. 1998;317:1309-12). Some had argued that for those non-significant results, a number needed should be presented as a single number without its confidence interval as it includes the possibility of no benefit or harm (McQuay HJ. Ann Intern Med. 1997;126:712-20). Other had suggested that it should not be reported when being non-significant (McAlister FA. CMAJ. 2008;179:549-53).
Our analyses with the Bayesian approach based on probability derived a number needed from the posterior distribution of the reciprocal of the absolute risk difference. Mathematically, its distribution stretches from minus ∞ to plus ∞ and can be bi-modal (as the probability of a number needed being zero is zero) (Thabane L. Biostatistics. 2003;4:365-70). The median of a number needed falls within its credible interval.
We also provided the estimates of the absolute risk difference in Supplementary table 3. When using them by the frequentist approach, the number needed to treat to harm (95% credible interval) is 4560 (-368, 110), 95 (16, 3461), 87(23, 348), 805 (-381, 56), 363 (-854, 56), and 184 (-1103, 17) for aspirin, low-intensity vitamin K antagonist, standard-intensity vitamin K antagonist, low-dose factor Xa inhibitor, standard-dose factor Xa inhibitor, and direct thrombin inhibitor, respectively.
We opted for presenting all numbers needed with their credible intervals by the Bayesian approach. However, neither the frequentist approach nor the Bayesian approach is ideal when reporting non-significant results. It should take extra caution when using and interpreting a number needed derived from an effect estimate that crosses the unity.
Finally, thank you for letting us clarify this.
Kang-Ling Wang and Marc Carrier
General Clinical Research Center, Taipei Veterans General Hospital, Taipei, Taiwan
Department of Medicine, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
Given the fact that some of the patients studied by Chou et al were characterised by the coexistence of , at least, four CHADS2 parameters, namely, Congestive heart failure, Hypertension, Age 75 or more, and Diabetes(1), it is to be expected that some of those patients will have stenotic cerebrovascular disease(both intracranial and extracranial)(2). In the latter study of 780 subjects presenting with stroke in the presence of nonvalvular atrial fibrillation(NVAF), concomitant cerebrovascular stenosis of 50% or more was identified in 231 patients. Multivariate analyses showed that CHADS2 score was an independent predictor of concomitant cerebral atherosclerosis(Odds Ratio 3.121; 95% Confidence Interval 1.770 to 5.504), and also a predictor of the presence of proximal stenosis at the symptomatic artery(OR, 3.043; 95% CI 1.458 to 6.350)(2).
When the CHADS2 score is associated with coronary heart disease(CHD) , as might have been the case in 1475 of the heart failure patients studied by Chou et al(1), CHADS2 predicts stroke in the total absence of NVAF(3). In the latter study, over a period of 5821 person-years of follow up, 40 out of 916 non anticoagulated patients with stable CHD and no NVAF suffered an ischaemic stroke/transient ischaemic attack. Compared with those with low(0-1) CHADS2 scores, those with progressively higher CHADS2 scores had a stepwise significant increase in rates of stroke/TIA(3). This increase in stroke rate might, arguably, hav...
Given the fact that some of the patients studied by Chou et al were characterised by the coexistence of , at least, four CHADS2 parameters, namely, Congestive heart failure, Hypertension, Age 75 or more, and Diabetes(1), it is to be expected that some of those patients will have stenotic cerebrovascular disease(both intracranial and extracranial)(2). In the latter study of 780 subjects presenting with stroke in the presence of nonvalvular atrial fibrillation(NVAF), concomitant cerebrovascular stenosis of 50% or more was identified in 231 patients. Multivariate analyses showed that CHADS2 score was an independent predictor of concomitant cerebral atherosclerosis(Odds Ratio 3.121; 95% Confidence Interval 1.770 to 5.504), and also a predictor of the presence of proximal stenosis at the symptomatic artery(OR, 3.043; 95% CI 1.458 to 6.350)(2).
When the CHADS2 score is associated with coronary heart disease(CHD) , as might have been the case in 1475 of the heart failure patients studied by Chou et al(1), CHADS2 predicts stroke in the total absence of NVAF(3). In the latter study, over a period of 5821 person-years of follow up, 40 out of 916 non anticoagulated patients with stable CHD and no NVAF suffered an ischaemic stroke/transient ischaemic attack. Compared with those with low(0-1) CHADS2 scores, those with progressively higher CHADS2 scores had a stepwise significant increase in rates of stroke/TIA(3). This increase in stroke rate might, arguably, have been attributable to left atrial dysfunction and its associated risk of concomitant left atrial prothrombotic milieu, given the fact that the study of 970 subjects(of whom only 35 had atrial fibrillation) showed that high CHADS2 score was associated with the lowest quartile of left atrial functional index (Odds Ratio 2.34, p=0.001)(4)
The association of older age and hypertension, also documented in the recent study(1), confers increased risk of carotid artery stenosis(CAS)(5). Given the fact that smoking also confers increased risk of CAS(5), it would be useful to ascertain the proportion of smokers in the study by Chou et al(1). Furthermore, according to the retrospective study of 3,435 NVAF patients who underwent carotid sonography, the prevalence of carotid plaques increased significantly with the increase in CHA2DS2-Vasc score(P for trend < 0.001). Multivariate logistic regression analysis showed that, for each 1 point increase in the CHA2DS2-Vasc score, there was a 37% increase in the prevalence of carotid plaques(6). Given the predictive power of CHADS2 for IS even in the absence of NVAF(3), the above observation could be extrapolated to heart failure patients who have a high CHADS2 score in the absence of NVAF. Occult paroxysmal atrial fibrillation(PAF), a parameter also not evaluated by Chou et al(1), may coexist with CAS, thereby compounding the risk of IS. The association of PAF and CAS was documented in a study which showed that CAS was prevalent in 13.5% of PAF patients of mean age 69(7).
In conclusion, for the sake of completeness, it would be useful to ascertain the proportion of smokers in the study by Chou et al(1). Documentation of PAF, left atrial functional index, and carotid artery sonography would also be useful indicators of the relative contributions of left atrial cardiomyopathy and CAS to IS prevalence in heart failure.
I have no funding and no conflict of interest
References
(1)Chou Y-L., Liou J-T., Cheng C-C., Tsai M-C., Lin W-S., Cheng S-M et al
The association of ischaemic stroke in patients with heart failure without atrial flutter/fibrillation
Heart 2019;doi:10.1136/heartjnl 2019-315646
(2) Kim DY., Cha MJ., Kim J., Lee DH., Lee HS., Nam CM., Nam HS et al
Increases in cerebral atherosclerosis according to CHADS2 scores in patients with stroke with nonvalvular atrial fibrillation#
STROKE 2011;42:930-934
(3) Welles CC., Whooley MA., Na B., Ganz P., Schiller NB., Turakhia MP
The CHADS2 score predicts ischemic stroke in the absence of atrial fibrillation among patients with coronary heart disease:Data from the Heart and Soul Study
Am Heart J 2011;162:555-561
(4)Azarbal F., Welles CC., Wong JM., Whooley MA., Schiller MB., Turakhia MP
Association of CHADS2, CHADS2-Vasc, R2CHADS2 scores with left atrial dysfunction in patients with coronary heart disease(from the Heart and Soul Study)
Am J Cardiol 2014;113;1166-1172
(5)Woo SY., Joh JH., Han S-A., Park H-C
Prevalence and risk factors for atherosclerotic carotid stenosis and plaque. A population-based screening study
Medicine 2017;96:4(e5999)
(6) Shang L., Zhao Y., Shao M., Sun H., Feng M., Li Y et al
The association of CHA2DS2-Vasc score and carotid plaque in patients with nonvalvular atrial fibrillation
LOS one 2019;14(2);e0210945
(7) Gu Y., Feng L., Xu Y., Zhao Y
Co-prevalence of carotid stenosis and coronary artery disease in Chinese patients with paroxysmal atrial fibrillation
Journal of International Medical Research 2014;42:1294-1300
On reading Dobson et al’s enlightening article we were saddened but not surprised to hear that nationally, there were no cardiology LTFT trainees training in electrophysiology (EP). Of course, it remains unclear as the relationship here: do trainees planning LTFT avoid EP, or do EP trainees fear reducing their hours will prove challenging?
Either way, this represents a great shame for both trainees and subspecialty. For trainees, the fulfilment of electrophysiological problem-solving and skilful intervention should be accessible to all regardless of hours worked. For the subspecialty, a growth in diversity of electrophysiologists as well as flexible working seems very sensible to ensure the continued growth of the subspecialty and its long-term sustainability. Ongoing initiatives by the BCS, BHRS, EHRA and others continue to advocate for a diverse and flexible workforce in EP, and we applaud these efforts.
Given the fact that high-grade carotid artery stenosis(CAS)(50% or more stenosis) is an independent risk factor for stroke in patients with coexisting nonvalvular atrial fibrillation(NVAF)(1), the optimum management of NVAF patients who have symptomatic CAS should be included among the key outstanding research questions enumerated by the authors of the recent review(2). In one study high-grade CAS was prevalent in 12%-14% of NVAF patients aged 71-80(3).. When high-grade CAS gives rise to amaurosis fugax , transient ischaemic attack(TIA), or stroke, the urgent priority is to mitigate the risk of subsequent occurrence of disabling stroke. That priority should prevail irrespective of presence or absence of coexisting NVAF. Strategies to mitigate that risk include initiation of dual antiplatelet therapy(4)(5) followed by interventional treatment of the CAS itself(6).
For patients in whom symptomatic CAS coexists with NVAF, when the latter is associated with a CHA2DS2-Vasc score that justifies oral anticoagulation to mitigate the risk of cardioembolis stroke , coprescription of oral anticoagulants has to be included in the management strategy. Furthermore after interventional treatment of symptomatic CAS, secondary prevention of neurological events(including stroke) necessitates long term antithrombotic medication with aspirin(5). Concurrently , in the presence of coexisting NVAF, long term primary prevention of cardioembolic stroke necessitates long...
Given the fact that high-grade carotid artery stenosis(CAS)(50% or more stenosis) is an independent risk factor for stroke in patients with coexisting nonvalvular atrial fibrillation(NVAF)(1), the optimum management of NVAF patients who have symptomatic CAS should be included among the key outstanding research questions enumerated by the authors of the recent review(2). In one study high-grade CAS was prevalent in 12%-14% of NVAF patients aged 71-80(3).. When high-grade CAS gives rise to amaurosis fugax , transient ischaemic attack(TIA), or stroke, the urgent priority is to mitigate the risk of subsequent occurrence of disabling stroke. That priority should prevail irrespective of presence or absence of coexisting NVAF. Strategies to mitigate that risk include initiation of dual antiplatelet therapy(4)(5) followed by interventional treatment of the CAS itself(6).
For patients in whom symptomatic CAS coexists with NVAF, when the latter is associated with a CHA2DS2-Vasc score that justifies oral anticoagulation to mitigate the risk of cardioembolis stroke , coprescription of oral anticoagulants has to be included in the management strategy. Furthermore after interventional treatment of symptomatic CAS, secondary prevention of neurological events(including stroke) necessitates long term antithrombotic medication with aspirin(5). Concurrently , in the presence of coexisting NVAF, long term primary prevention of cardioembolic stroke necessitates long term oral anticoagulation. Future research should address the issue of the optimum choice of oral anticoagulant to be coprescribed with aspirin so as to optimise stroke prevention concurrently with mitigation of the risk of iatrogenic bleeding.
For all these issues to be fully addressed the minimum requirement is that the work-up of all older(?aged 60 or more) NVAF patients should include carotid arty sonography, and the incorporation of high-grade CAS(if present) in the CHA2DS2-Vasc score.
I have no funding and no conflict of interest.
References
(1) Chang Y-J., Ryu S-J., Lin S-K
Carotid artery stenosis in ischemic stroke patients with nonvalvular atrial fibrillation
Cerebrovascular Diseases 2002;13:16-20
(2) Stroke and thromboembolism in atrial fibrillation
Heart 2019
(3) Kanter MC., Tegeler CH., Pearce LA., Weinberger J., Feinberg WM., Anderson DC et al
Carotid stenosis in aptients with atrial fibrillation
Arch Intern Med 1994;154:1372-1377
(4) Batchelder A., Hubter J., Cairns V., Sandford R., Munshi A., Naylor AR
Dual antiplatelet therapy prior to expedited carotid surgery reduces recurrent events prior to surgery without significantly increasing peri-operative bleeding complications
Eur J Vasc Endovasc Surg 2015;50:412-419
(5) Ricotta JJ., AbuRahma A., Ascher E., Eskandari M., Faries P., Lal BK
Updated Society for Vascular Surgery guidelines for management of extracranial carotid disease
J Vasc Surg 2011;54:e1-e31
(6)Brott TG., Hobson RW., Howard G., Roubin GS., Clark WM., Brooks W et al
Stenting versus endarterectomy for treatment of carotid artery stenosis
N Engl J Med 2010;363:11-23
Echocardiography has been shown to generate decisive diagnostic information when pulmonary embolism(PE) presents atypically with paradoxical cerebral embolism in the absence of concurrent PE-related stigmata such as dyspnoea, chest pain, or haemoptysis(1)(2), and also in those cases where the atypical presentation is one which simulates ST segment elevation myocardial infarction(STEMI) in the absence of paradoxical coronary artery embolism(3).
The following are some anecdotal report which exemplify the diagnostic role of echocardiography:-
A 32 year old man presented with a stroke , but no concurrent breathlessness or clinical signs of deep vein thrombosis(DVT). Transthoracic echocardiography(TTE) revealed intracardiac thrombus and also a thrombus in the main pulmonary artery. A subsequent Doppler examination revealed a DVT in the right lower limb(1).
In another report, a 55 year old man presented with a stroke and no concurrent breathlessness. However, he had a blood pressure of 70/40 mm Hg and an elevated serum troponin of 0.07 ng/ml(normal < 0.03 ng/ml). TTE revealed a "positive bubble study" which was followed up with a transoesopahageal echocardiogram(TOE) which showed a patent foramen ovale(PFO). A subsequent Duplex study revealed right lower limb DVT.. His management included intracardiac surgery, which revealed biatrial thrombus straddling a patent foramen ovale. An extensive pulmonary thrombus was also discovered(...
Echocardiography has been shown to generate decisive diagnostic information when pulmonary embolism(PE) presents atypically with paradoxical cerebral embolism in the absence of concurrent PE-related stigmata such as dyspnoea, chest pain, or haemoptysis(1)(2), and also in those cases where the atypical presentation is one which simulates ST segment elevation myocardial infarction(STEMI) in the absence of paradoxical coronary artery embolism(3).
The following are some anecdotal report which exemplify the diagnostic role of echocardiography:-
A 32 year old man presented with a stroke , but no concurrent breathlessness or clinical signs of deep vein thrombosis(DVT). Transthoracic echocardiography(TTE) revealed intracardiac thrombus and also a thrombus in the main pulmonary artery. A subsequent Doppler examination revealed a DVT in the right lower limb(1).
In another report, a 55 year old man presented with a stroke and no concurrent breathlessness. However, he had a blood pressure of 70/40 mm Hg and an elevated serum troponin of 0.07 ng/ml(normal < 0.03 ng/ml). TTE revealed a "positive bubble study" which was followed up with a transoesopahageal echocardiogram(TOE) which showed a patent foramen ovale(PFO). A subsequent Duplex study revealed right lower limb DVT.. His management included intracardiac surgery, which revealed biatrial thrombus straddling a patent foramen ovale. An extensive pulmonary thrombus was also discovered(2).
Echocardiography also has a role in identifying hitherto unsuspected PE in a patient who presents with an electrocardiogram(ECG) simulating ST segment elevation myocardial infarction(STEMI). One such patient was a 63 year old man who was admitted with cardiac arrest in the context of multiple risk factors for acute myocardial infarction and previous placement of a coronary artery stent. His ECG showed marked ST segment elevation(simulating the "tombstone" pattern) in the anterior leads, but coronary coronary angiography did not reveal any coronary artery occlusion in the epicardial arteries, and the left anterior descending artery stent was patent. A bedside echocardiogram was performed "emergently", and it revealed a dilated right ventricle, thereby raising a suspicion of massive pulmonary embolism. This provisional diagnosis was validated by pulmonary angiography. Pulmonary embolectomy was performed, but the patient subsequently died(3).
Comment:-
"Emergent" echocardiography should, arguably, be a routine component of the "workup" of a patient presenting with crytpogenic stroke, so as to mitigate the risk of missed diagnosis of PE-related paradoxical cerebral embolism.
Likewise, given the increasing awareness of the entity of PE presenting with an ECG simulating STEMI in the absence of paradoxical coronary artery embolism(4), the work up of such patients should routinely include TTE, with the specific aim of identifying stigmata of PE.
References
(1) Kumar T., Budnur SC., Mahadevappa NC., Singla V
Paradoxical embolism via patent foramen ovale
BMJ case Rep 2013;doi 10.1136/bcr-2013-009818
(2)dada R., dada J., Abdelsalam M., Agrawal Y
Thrombus straddling a patent foramen ovale, pulmonary embolism and paradoxical embolism: a rare trifata
BMJ case Reports 2018;doi:10.1136/bcr-2018-227505
(3)Ghatak A., Alsulaimi A., Acosta YM., ferreira A
Acute pulmonary embolism masquerading as acute myocardial infarction
Proc Bayl Univ Med Cent 2015;28:69-70
(4)Villablanca PA., Vlismas PP., Alexandrovich T., Omondi A., Gupta T et al
Case report and systematic review of pulmonary embolism mimicking ST elevation myocardial infarction
Vascular 2019;27:90-97
The focus on left atrial dimensions in the risk stratification of patients with atrial fibrillation(AF) and also in those without AF(1), is a timely departure from the prevailing preoccupation with AF-related risk stratification strategies such as the CHA2 DS2-Vasc score which do not include evaluation of left atrial function(2), notwithstanding the hypothesis that the predictive ability of the CHADS2 index to stratify stroke risk may be mechanistically linked to severity of left atrial dysfunction(3). In the latter study left atrial functional index(LAFI) was the parameter utilised to evaluate left atrial function. Regression analysis showed that mean LAFI significantly(p < 0.001) decreased across tertiles of CHADS2(42.8, 37.8, 36.7). After adjustment for age, sex, race, and other parameters , high CHADS2 remained significantly associated with the lowest quartile of LAFI(Odds Ratio 2.34). For every point increase in CHADS2 the LAFI decreased by 4 %. Secondary analyses using CHA2 DS2 Vasc score replicated these results(3). In view of these observations LAFI is a potential modality to risk stratify nonvalvular atrial fibrillation(NVAF) subjects such as those with CHA2DS2 Vasc score of zero , who might otherwise be ineligible for thromboprophylaxis with oral anticoagulants. LAFI could even be utilised to evaluate eligibility for thromboprophylaxis in patients with excessive atrial ectopic activity or short-run atrial tachyarrhythmis, given the fact that each...
The focus on left atrial dimensions in the risk stratification of patients with atrial fibrillation(AF) and also in those without AF(1), is a timely departure from the prevailing preoccupation with AF-related risk stratification strategies such as the CHA2 DS2-Vasc score which do not include evaluation of left atrial function(2), notwithstanding the hypothesis that the predictive ability of the CHADS2 index to stratify stroke risk may be mechanistically linked to severity of left atrial dysfunction(3). In the latter study left atrial functional index(LAFI) was the parameter utilised to evaluate left atrial function. Regression analysis showed that mean LAFI significantly(p < 0.001) decreased across tertiles of CHADS2(42.8, 37.8, 36.7). After adjustment for age, sex, race, and other parameters , high CHADS2 remained significantly associated with the lowest quartile of LAFI(Odds Ratio 2.34). For every point increase in CHADS2 the LAFI decreased by 4 %. Secondary analyses using CHA2 DS2 Vasc score replicated these results(3). In view of these observations LAFI is a potential modality to risk stratify nonvalvular atrial fibrillation(NVAF) subjects such as those with CHA2DS2 Vasc score of zero , who might otherwise be ineligible for thromboprophylaxis with oral anticoagulants. LAFI could even be utilised to evaluate eligibility for thromboprophylaxis in patients with excessive atrial ectopic activity or short-run atrial tachyarrhythmis, given the fact that each of those arrhythmias is an independent risk factor for ischemic stroke(4)(5).
The ultimate risk factor for left atrium-related cadiogenic thromboembolism is the documentation of a prothrombotic state in the left atrium and left atrial appendage(LAA), but this entails the use of an invasive strategy, namely, trans oesophageal echocardiography(TOE)(6). Recourse to this modality could be circumvented if a correlation cloud be shown to exist between LAFI and LAA abnormalities such as smoke, sludge, and thrombus. Already, the CHA2DS2 Vasc score has been shown to be significantly associated with TOE risk factors for thromboembolism(7). The next step is also to explore the potential association between LAFI and TOE risk factors for thrromboembolism .
Given the fact that echocardiographically documented left atrial strain has been shown to predict a prothrombotic state in patients with NVAF(8) it would also be worthwhile to explore a potential relationship between LAFI and left atrial strain, not only in NVAF ,but also in subjects with excessive atrial ectopic activity and in subjects with short-run atrial tachyarrhythmia. Furthermore, given the fact that atrial fibrosis(documented by late gadolinium enhancement magnetic resonance imaging[LGE-MRI]) has been shown to predict occurrence of incident atrial fibrillation in non-AF subjects of mean age 49(9), it might be informative to explore a correlation between LAFI and the extent and distribution of atrial fibrosis.
In conclusion, if LAFI proves to be significantly correlated with parameters of the prothrombotic state and also correlated with the extent and distribution of left atrial fibrosis, it might be the modality of choice for stratification of risk of left atrial-related cardiogenic thromboembolism either in NVAF or in patients with excessive atrial ectopic activity or short-run atrial tachyarrhytmia.
References
(1) Froehlich L., Meyre P., Aeschbacher S et al
Left atrial dimensions and cardiovascular outcomes in patients with and without atrial fibrillation: A systematic review and meta analysis
Heart 2019;doi:10.1136/heartjnl 2019-315174
(2) Lip GYH., Nieuwlaat R., Oisters R
Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach
CHEST 2010;137:263-272
(3)Azarbal F., Welles C., Wong JM et al
Association of CHA2DS2-Vasc and RCHADS2 scores with atrial dysfunction in patients with coronary heart disease(from the Heart and Soul Study)
Am J Cardiol 2014;113:1166-1172
(4) Marinheiro R., Parreira L., Amador P et al
Excessive atrial ectopic activity as an independent risk factor for ischemic stroke
Int J Cardiol 2017;240:226-230
(5) Yzamada S., Lin C-Y., Cahng S-L et al
Risk of stroke in patients with short-run atrial tachyarrhythmia
STROKE 2017;48:3232-3238
(6)Dinh T., Baur LH., Pisters R et al
Aspirin versus vitamin K antagonist treatment guided by transoesophageal echocardiography in patients with atrial fibrillation: a pilot study
Heart 2014;100;563-558
(7) Willens HJ., Gomez-Marin O., Nelson K et al
Correlation of CHADS2 and CHA2 DS2 Vasc scores with transesophageal echocardiography irisk factors for thromboembolism in a multi-ethnic United States population with nonvalvular atrial fibrillation
Journal of the American Society of echocardiography 2013;26:175-184
(8) Kupczynska K., Michalski BW., Miskowicc D et al
Association between left atrial function assessed by speckle-tracking echocardiography and the presence of atrial appendage thrombus in aptients with atrial fibrillation
Anatoll J cardiol 2017;18:15-22
(9) Siebramair J., Suksaranjit P., McGann CJ et al
Atrial fibrosis in non-atrial fibrillation individuals and prediction of atrial fibrillation by use of late gadolinium enhancement magbetic resonance imaging
J cardiovasc Electophysiol 2019;30:550-556
Given the fact that acute myocardial infarction(AMI)(1), left bundle branch block(LBBB)(2), and pulmonary embolism(PE), are all age-related disorders, the authors of the recent study correctly highlighted the importance of including PE in the differential diagnosis of the association of suspected AMI and LBBB(2). For the purpose of identifying those patients who are most likely to have AMI the authors proposed the use of serum troponin as a rule-in criterion during the first 3 hours of hospital admission . By implication the inclusion of PE in the differential diagnosis should be deferred for at least 3 hours, and only activated in patients who do not have a raised serum troponin level.
However, in view of the fact that elevation in serum troponin may be a feature in the presentation of PE(4), and also in view of the fact that transient LBBB has been reported in a 59 year old patient with PE(5), the latter disorder should be included in the differential diagnosis of the association of acute coronary syndrome and LBBB. In the 59 year old patient who was reported with PE and LBBB, serial troponin levels were 0.38, 0.41, and 1.12 ng/ml(reference range 0-0.04)(5), arguably justifying early coronary angiography(2). That patient had neither pleuritic pain nor breathlessness to raise the index of suspicion for PE. Coronary angiography ruled out coronary artery occlusion, and helical computed tomography revealed extensive PE involving the main branches of both pul...
Given the fact that acute myocardial infarction(AMI)(1), left bundle branch block(LBBB)(2), and pulmonary embolism(PE), are all age-related disorders, the authors of the recent study correctly highlighted the importance of including PE in the differential diagnosis of the association of suspected AMI and LBBB(2). For the purpose of identifying those patients who are most likely to have AMI the authors proposed the use of serum troponin as a rule-in criterion during the first 3 hours of hospital admission . By implication the inclusion of PE in the differential diagnosis should be deferred for at least 3 hours, and only activated in patients who do not have a raised serum troponin level.
However, in view of the fact that elevation in serum troponin may be a feature in the presentation of PE(4), and also in view of the fact that transient LBBB has been reported in a 59 year old patient with PE(5), the latter disorder should be included in the differential diagnosis of the association of acute coronary syndrome and LBBB. In the 59 year old patient who was reported with PE and LBBB, serial troponin levels were 0.38, 0.41, and 1.12 ng/ml(reference range 0-0.04)(5), arguably justifying early coronary angiography(2). That patient had neither pleuritic pain nor breathlessness to raise the index of suspicion for PE. Coronary angiography ruled out coronary artery occlusion, and helical computed tomography revealed extensive PE involving the main branches of both pulmonary arteries(5).
The true prevalence of PE-related LBBB is not known. It might be more prevalent than implied by the occasional anecdote, where it is tachycardia-dependent(5), given the fact that PE, itself, is commonly characterised by sinus tachycardia(6). Conversely, sinus bradycardia is distinctly uncommon in PE(7)(8)(9)(10). Even more unusual is the transient resolution of pre-existing LBBB following the onset of PE, as was the case in a 61 year old man with coexisting deep vein thrombosis(DVT)(11). Accordingly, at the very least, the work-up of an elderly patient with the association of acute coronary syndrome and LBBB should include clinical evaluation for DVT, irrespective of troponin status.
I have no funding and no conflict of interest
References
(1) Sanchis-Gomar F., Perez-Quillis C., Leischik R., Lucia A
Epidemiology of coronary heart disease and acute coronary syndrome
Ann Transl Med 2016;4:256
(2) Nestelberger T., Cullen L., Lindahl B., Reichlin T., Greenslade JH., Giannitsis E., Christ M et al
Diagnosis of acute myocardial infarction in the presence of left bundle branch block
Heart 2019;doi:10.1136/heartjnl-2018-314673
(3) Heit JA., Spencer FA., White RH
The epidemiology of venous thromboembolism
J Thromb Thrombolysis 2016;41:3-14
(4) Lankeit M., Friesen D., Aschoff J., Delias C., HasenfuB G., Katus H et al
Highly sensitive troponin T assay in normotensive patients with acute pulmonary embolism
Eur Heart J 2010;31:1836-1844
(5) Kasmani R., Okoli K., Mohan G., Casey K., Ledrick D
Transient left bundle branch block: an unusual electrocardiogram in acute pulmonary embolism
Am J Med Sc 2009;337:381-382
(6) Raghav KPS., Makkuni P., Figuerdo VM
A review of electrocardiography in pulmonary embolism: recognising pulmonary embolism masquerading as ST-elevation myocardial infarction
Reviews in Cardiovascular Medicine 2011;12:157-163
(7) Khosravi A., Andalib E., Khaledifar A., Hajizadeh M., Nejati M., Behjati M
Pulmonary thromboembolism presenting with recurrent bradycardia and hypotension
National Research Institute of Tuberculosis and Lung Disease, Iran 2017;16:248-250
(8) Larsen TR., Ball TC
Chronic pulmonary embolism in a young athletic woman
Proc Bayl Univ Cent 2015;28:371-374
(9) Lee J-W., Cha S-I., Jung C-Y., Choi W-I., Jeon K-N et al
Clinical course of pulmonary embolism in lung cancer patients
Respiration 2009;78:42-48
(10) Catella P., Wiesel S., Siddiqui A., Chalhoub M
A rare case of pulmonary embolism induced symptomatic bradycardia
American Journal of Respiratory and Critical Care Medicine 2017;195:A5492
(11) Athar SM., Chin BSP., Flint EJ
Transient disappearance of left bundle branch block pattern ; an unusual ECG presentation of acute pulmonary embolism
Postgrad Med J 2002;78:555-558
In the context of suspected cardiac implantable electronic device infection a fundamental flaw in transoesophageal echocardiography(TOE) is that this modality does not distinguish between infective and non infective masses situated on the electronic device lead. For example, in one study 25 patients who underwent TOE were shown to have either a lead vegetation(11 cases) or lead strands(13 cases) or both(1 case). Nevertheless, 18 of of those 25 patients proved, after exhaustive evaluation, to have no evidence of infection(1). According to a recent report, however, guided biopsy of a lead-associated mass, by means of a biotome, can facilitate the distinction between an infective versus non infective device-related mass. In Case 1 of that report an 80 year old woman with a pacemaker presented with mild leucocytosis in the setting of a recent dental procedure, but was afebrile. Transoesophageal echocardiography(TOE) disclosed a 1.6 X 1.0 cm mass on her right atrial lead. Using femoral access and fluoroscopic guidance the mass was biopsied under TOE guidance. The mass proved to be a thrombus with irregular fragments of soft tissue. The gram stain showed no polymorphonuclear cells and the tissue culture confirmed no growth. Case 2 in that report was a 29 year old man with an implantable cardioverter-defibrillator in the setting of intermittent fever and night sweats. TOE revealed a 2.9 cm X 1.2 mass encasing the device lead. A single blood culture grew a Propionib...
In the context of suspected cardiac implantable electronic device infection a fundamental flaw in transoesophageal echocardiography(TOE) is that this modality does not distinguish between infective and non infective masses situated on the electronic device lead. For example, in one study 25 patients who underwent TOE were shown to have either a lead vegetation(11 cases) or lead strands(13 cases) or both(1 case). Nevertheless, 18 of of those 25 patients proved, after exhaustive evaluation, to have no evidence of infection(1). According to a recent report, however, guided biopsy of a lead-associated mass, by means of a biotome, can facilitate the distinction between an infective versus non infective device-related mass. In Case 1 of that report an 80 year old woman with a pacemaker presented with mild leucocytosis in the setting of a recent dental procedure, but was afebrile. Transoesophageal echocardiography(TOE) disclosed a 1.6 X 1.0 cm mass on her right atrial lead. Using femoral access and fluoroscopic guidance the mass was biopsied under TOE guidance. The mass proved to be a thrombus with irregular fragments of soft tissue. The gram stain showed no polymorphonuclear cells and the tissue culture confirmed no growth. Case 2 in that report was a 29 year old man with an implantable cardioverter-defibrillator in the setting of intermittent fever and night sweats. TOE revealed a 2.9 cm X 1.2 mass encasing the device lead. A single blood culture grew a Propionibacterium species thought to be a contaminant. The device-associated mass was biopsied using the same technique as in Case 1. Histology of the biopsy specimen revealed "pieces of fibrin mixed with neutrophils harboring calcification, consistent with an infectious etiology". Lead extraction was undertaken. Culture of the extracted lead tip was positive for Propionibacterium, thereby disproving the previous hypothesis that the organism was a contaminant. The authors of the case reports stress that the safety of this technique still needs further investigation. Furthermore, performing a biopsy using this technique carries a risk of lead dislodgement(2).
I have no funding and no conflict of interest
References
(1) Downey BC., Juselius WE., Pandian NG., Estes NAM., Link MS
Incidence and significance of pacemaker and implantable cardioverter-defibrillator lead masses discovered during transosophageal echocardiography
PACE 2011;34:679-683
(2)Chang D., Gabriels J., Laighold S., Williamson AK., Isnail H., Epstein LM
A novel diagnostic approach to a mass on a device lead
Heart Rhythm Case Reports doi.org/10.1016/hrcr.2019.03.001 Article in Press
Notwithstanding the high costs and lack of reimbursement associated with the use of positron emission tomography/computed tomography(PET/CT) in suspected cardiac implantable electronic device (CIED) infection(1), the ability of this modality to distinguish between infective and non infective vegetations is a powerful argument for its inclusion in the workup of suspected CIED. Evidence of the ability to make this distinction comes from two sources(2)(3). Firstly, in a retrospective study of 177 transoesophageal echocardiographic studies performed on 153 consecutive patients, a visible mass was observed on a device lead in 25 instances. In 11 studies this was a lead vegetation, in 13 instances only lead strands were seen, and in one instance a lead vegetation coexisted with a lead strand. Nevertheless, 18 of the 25 patients with lead-associated masses had no other evidence of infection. In that study the presence or absence of infection was adjudicated by three clinical investigators who independently reviewed all available clinical data without knowledge of the echocardiographic results(2). In another study, 63 consecutive patients(mean age 68.6) with suspected CIED were evaluated both by echocardiography(tranasthoracic and transoesophageal) and by PET/CT. Echocardiography was associated with a positive predictive value(PPV) of 83.3%, and a negative predictive value(NPV) of 69.2%. For PET/CT, PPV and NPV amounted to 100% and 93.9%, respectively(3). The additional ut...
Notwithstanding the high costs and lack of reimbursement associated with the use of positron emission tomography/computed tomography(PET/CT) in suspected cardiac implantable electronic device (CIED) infection(1), the ability of this modality to distinguish between infective and non infective vegetations is a powerful argument for its inclusion in the workup of suspected CIED. Evidence of the ability to make this distinction comes from two sources(2)(3). Firstly, in a retrospective study of 177 transoesophageal echocardiographic studies performed on 153 consecutive patients, a visible mass was observed on a device lead in 25 instances. In 11 studies this was a lead vegetation, in 13 instances only lead strands were seen, and in one instance a lead vegetation coexisted with a lead strand. Nevertheless, 18 of the 25 patients with lead-associated masses had no other evidence of infection. In that study the presence or absence of infection was adjudicated by three clinical investigators who independently reviewed all available clinical data without knowledge of the echocardiographic results(2). In another study, 63 consecutive patients(mean age 68.6) with suspected CIED were evaluated both by echocardiography(tranasthoracic and transoesophageal) and by PET/CT. Echocardiography was associated with a positive predictive value(PPV) of 83.3%, and a negative predictive value(NPV) of 69.2%. For PET/CT, PPV and NPV amounted to 100% and 93.9%, respectively(3). The additional utility of PET/CT is the ability to detect "unsuspected extracardiac sites of infection in up to 23% of patients with device-related sepsis"(4), thereby facilitating the fulfilment of Duke criteria for infective endocarditis(5). In those instances where the sensitivity of PET/CT is suboptimal that shortcoming is largely attributable to prior antibiotic use(6). Furthermore, negative PET/CT also identifies a group of patients who have excellent outcome without device extraction(6).
I have no funding, and no conflict of interest.
References
(1) DeSimone DC., Sohali MR., Mulpuru SK
Contemporary management of cardiac implantable electronic device infection
Heart 2019;105:961-965
(2)Downey BC., Juselius WE.,Pandian NG., Estes NAM., Link MS
Incidence and significance of pacemaker and implantable cardioverter-defibrillator lead masses discovered during transesophageal echocardiography
PACE 2011;34:679-683
(3) Erba PA., Sollini M., Conti U., Bandera F., Tascini C., De Tommasi SM
Radiolabeled WBC scintigraphy in the diagnostic work up of patients with suspected device-related infections
JACC Cardiovascular Imaging 2013;6:1075-1086
(4) Gutierrez-Carretero E., Rezaei K., Rodriguez-Mora F., de Alarcon A
Infections on cardiovascular implantable electronic devices: A critical review
Medical Research Archives 2019;Issue 3;page 1 to 64
(5) Tak T., Shukla S
Molecular diagnosis of infective endocarditis: a helpful addition to Duke criteria
Clin Med Res 2004;2:206-208
(6) Sarrazin J-F., Phillippon F., Trottier M., Tessier M
Role of radionuclide imaging for diagnosis of device and prosthetic valve infections
World Journal of Cardiology 2016;8:534-546
Under the heading "Changes in kidney function during intercurrent illness"(1) mention must be made of the risk of acute kidney injury when nonsteroidal anti inflammatory drugs(NSAIDs) are prescribed for acute gout, the latter complication(the equivalent of "intercurrent illness") sometimes documented as a consequence of diuretic use in congestive heart failure(CHF)(2). Coprescription of NSAIDs, diuretics, and angiotensin converting enzyme inhibitors(or angiotensin receptor blockers), so-called triple therapy, is associated with increased risk of acute kidney injury(rate ratio 1.31, 95% Confidence Interval 1.12 to 1.53)(3). This was shown in a nested case-control study which enrolled patients in whom hypertension was the indication for prescription of diuretics and/or angiotensin converting enzyme inhibitors(or angiotensin receptor blockers)(3), but might be equally applicable in the context of CHF. Additionally, among CHF patients who have a drug regime which includes spironolactone, the use of NSAIDs might increase the risk of hyperkalaemia. The rationale is that NSAIDs "interfere with the stimulatory effect of prostaglandins on the release of renin"(4). The risk of hyperkalaemia may be compounded by concurrent use of beta adrenergic blocking agents(4).
For all the above reasons, NSAIDs should be contraindicated in CHF patients with gout. The recommended alternatives include colcichine(5) and intraarticuoar corticosteroids(6), resp...
Under the heading "Changes in kidney function during intercurrent illness"(1) mention must be made of the risk of acute kidney injury when nonsteroidal anti inflammatory drugs(NSAIDs) are prescribed for acute gout, the latter complication(the equivalent of "intercurrent illness") sometimes documented as a consequence of diuretic use in congestive heart failure(CHF)(2). Coprescription of NSAIDs, diuretics, and angiotensin converting enzyme inhibitors(or angiotensin receptor blockers), so-called triple therapy, is associated with increased risk of acute kidney injury(rate ratio 1.31, 95% Confidence Interval 1.12 to 1.53)(3). This was shown in a nested case-control study which enrolled patients in whom hypertension was the indication for prescription of diuretics and/or angiotensin converting enzyme inhibitors(or angiotensin receptor blockers)(3), but might be equally applicable in the context of CHF. Additionally, among CHF patients who have a drug regime which includes spironolactone, the use of NSAIDs might increase the risk of hyperkalaemia. The rationale is that NSAIDs "interfere with the stimulatory effect of prostaglandins on the release of renin"(4). The risk of hyperkalaemia may be compounded by concurrent use of beta adrenergic blocking agents(4).
For all the above reasons, NSAIDs should be contraindicated in CHF patients with gout. The recommended alternatives include colcichine(5) and intraarticuoar corticosteroids(6), respectively. According to the American College of Physicians Clinical Practice Guideline moderate quality evidence shows that colcichine 1.2 mg followed by 0.6 mg after 1 hour can be as effective, for pain control, as 1.2 mg followed by 0.6 mg/h for 6 hours. The lower dose regime is associated with lower prevalence of diahrroea(23% vs 77%)(5). The alternative is the use of intra articular corticosteroids, advocated in Australia(6), but not licensed for use in the UK.
I have on funding and no conflict of interest
References
(1) Change in renal function associate with drug treatment in heart failure: national guidance
Heart June 2019
(2) Spieker LE., Ruschitzka FT., Luscher TF., Noll G
The management of hyperuricemia and gout in patients with heart failure
Eur J Heart Failure 2002;4:403-410
(3)Lapi F., Azoulay L., Yin H., Nessim SJ., Suissa S
Concurrent use of diuretics, angiotensin converting enzyme inhibitors, and angiotensin receptor blockers with nonsteroidal anti-inflammatory drugs and risk of acute kidney injury: nested case-control study
BMJ 2013;346:e8525
(4) Palmer BF
Managing hyperkalemia caused by inhibitors of the renin-angiotensin-aldosterone system
N Engl J Med 2004;351:585-592
(5) Qaseem A., Harris RP., Forciea MA., for the Clinical Guideline Committee of the American College of Physicians
Management of acute and recurrent gout: A clinical practice guideline for the American College of Physicians
Ann Intern Med 2017;166:58-68
(6) Robinson PC., Stamp LK
The management of gout: Much has changed
RACGP 2016;45:299-302
This is our response to a concern raised by a reader regarding the estimates and credible intervals of those numbers needed to treat to harm presented in our article titled “Extended treatment of venous thromboembolism: a systematic review and network meta-analysis.”
First, we confirm that data published in the Journal are valid and correct.
We also like to thank the reader to point it out as a number needed (either for benefit or harm) derived from an effect estimate that crosses the unity has been intuitively challenging to visualize (Hutton JL. Br J Haematol. 2009;146:27-30). Because it is given by the reciprocal of the absolute risk difference, a number needed can never include zero but straddles plus and minus infinity ∞ when the absolute risk difference include zero. By the frequentist approach based on inverting the confidence interval of the absolute risk difference, it represents that the number needed encompasses two disjoint regions: one from upper confidence interval to plus ∞ and the other from lower confidence interval to minus ∞ (Altman DG. BMJ. 1998;317:1309-12). Some had argued that for those non-significant results, a number needed should be presented as a single number without its confidence interval as it includes the possibility of no benefit or harm (McQuay HJ. Ann Intern Med. 1997;126:712-20). Other had suggested that it should not be reported when being non-significant (McAlister FA. CMAJ. 2008;179:549-53).
Our analyses with t...
Show MoreGiven the fact that some of the patients studied by Chou et al were characterised by the coexistence of , at least, four CHADS2 parameters, namely, Congestive heart failure, Hypertension, Age 75 or more, and Diabetes(1), it is to be expected that some of those patients will have stenotic cerebrovascular disease(both intracranial and extracranial)(2). In the latter study of 780 subjects presenting with stroke in the presence of nonvalvular atrial fibrillation(NVAF), concomitant cerebrovascular stenosis of 50% or more was identified in 231 patients. Multivariate analyses showed that CHADS2 score was an independent predictor of concomitant cerebral atherosclerosis(Odds Ratio 3.121; 95% Confidence Interval 1.770 to 5.504), and also a predictor of the presence of proximal stenosis at the symptomatic artery(OR, 3.043; 95% CI 1.458 to 6.350)(2).
Show MoreWhen the CHADS2 score is associated with coronary heart disease(CHD) , as might have been the case in 1475 of the heart failure patients studied by Chou et al(1), CHADS2 predicts stroke in the total absence of NVAF(3). In the latter study, over a period of 5821 person-years of follow up, 40 out of 916 non anticoagulated patients with stable CHD and no NVAF suffered an ischaemic stroke/transient ischaemic attack. Compared with those with low(0-1) CHADS2 scores, those with progressively higher CHADS2 scores had a stepwise significant increase in rates of stroke/TIA(3). This increase in stroke rate might, arguably, hav...
On reading Dobson et al’s enlightening article we were saddened but not surprised to hear that nationally, there were no cardiology LTFT trainees training in electrophysiology (EP). Of course, it remains unclear as the relationship here: do trainees planning LTFT avoid EP, or do EP trainees fear reducing their hours will prove challenging?
Either way, this represents a great shame for both trainees and subspecialty. For trainees, the fulfilment of electrophysiological problem-solving and skilful intervention should be accessible to all regardless of hours worked. For the subspecialty, a growth in diversity of electrophysiologists as well as flexible working seems very sensible to ensure the continued growth of the subspecialty and its long-term sustainability. Ongoing initiatives by the BCS, BHRS, EHRA and others continue to advocate for a diverse and flexible workforce in EP, and we applaud these efforts.
Given the fact that high-grade carotid artery stenosis(CAS)(50% or more stenosis) is an independent risk factor for stroke in patients with coexisting nonvalvular atrial fibrillation(NVAF)(1), the optimum management of NVAF patients who have symptomatic CAS should be included among the key outstanding research questions enumerated by the authors of the recent review(2). In one study high-grade CAS was prevalent in 12%-14% of NVAF patients aged 71-80(3).. When high-grade CAS gives rise to amaurosis fugax , transient ischaemic attack(TIA), or stroke, the urgent priority is to mitigate the risk of subsequent occurrence of disabling stroke. That priority should prevail irrespective of presence or absence of coexisting NVAF. Strategies to mitigate that risk include initiation of dual antiplatelet therapy(4)(5) followed by interventional treatment of the CAS itself(6).
Show MoreFor patients in whom symptomatic CAS coexists with NVAF, when the latter is associated with a CHA2DS2-Vasc score that justifies oral anticoagulation to mitigate the risk of cardioembolis stroke , coprescription of oral anticoagulants has to be included in the management strategy. Furthermore after interventional treatment of symptomatic CAS, secondary prevention of neurological events(including stroke) necessitates long term antithrombotic medication with aspirin(5). Concurrently , in the presence of coexisting NVAF, long term primary prevention of cardioembolic stroke necessitates long...
Echocardiography has been shown to generate decisive diagnostic information when pulmonary embolism(PE) presents atypically with paradoxical cerebral embolism in the absence of concurrent PE-related stigmata such as dyspnoea, chest pain, or haemoptysis(1)(2), and also in those cases where the atypical presentation is one which simulates ST segment elevation myocardial infarction(STEMI) in the absence of paradoxical coronary artery embolism(3).
Show MoreThe following are some anecdotal report which exemplify the diagnostic role of echocardiography:-
A 32 year old man presented with a stroke , but no concurrent breathlessness or clinical signs of deep vein thrombosis(DVT). Transthoracic echocardiography(TTE) revealed intracardiac thrombus and also a thrombus in the main pulmonary artery. A subsequent Doppler examination revealed a DVT in the right lower limb(1).
In another report, a 55 year old man presented with a stroke and no concurrent breathlessness. However, he had a blood pressure of 70/40 mm Hg and an elevated serum troponin of 0.07 ng/ml(normal < 0.03 ng/ml). TTE revealed a "positive bubble study" which was followed up with a transoesopahageal echocardiogram(TOE) which showed a patent foramen ovale(PFO). A subsequent Duplex study revealed right lower limb DVT.. His management included intracardiac surgery, which revealed biatrial thrombus straddling a patent foramen ovale. An extensive pulmonary thrombus was also discovered(...
The focus on left atrial dimensions in the risk stratification of patients with atrial fibrillation(AF) and also in those without AF(1), is a timely departure from the prevailing preoccupation with AF-related risk stratification strategies such as the CHA2 DS2-Vasc score which do not include evaluation of left atrial function(2), notwithstanding the hypothesis that the predictive ability of the CHADS2 index to stratify stroke risk may be mechanistically linked to severity of left atrial dysfunction(3). In the latter study left atrial functional index(LAFI) was the parameter utilised to evaluate left atrial function. Regression analysis showed that mean LAFI significantly(p < 0.001) decreased across tertiles of CHADS2(42.8, 37.8, 36.7). After adjustment for age, sex, race, and other parameters , high CHADS2 remained significantly associated with the lowest quartile of LAFI(Odds Ratio 2.34). For every point increase in CHADS2 the LAFI decreased by 4 %. Secondary analyses using CHA2 DS2 Vasc score replicated these results(3). In view of these observations LAFI is a potential modality to risk stratify nonvalvular atrial fibrillation(NVAF) subjects such as those with CHA2DS2 Vasc score of zero , who might otherwise be ineligible for thromboprophylaxis with oral anticoagulants. LAFI could even be utilised to evaluate eligibility for thromboprophylaxis in patients with excessive atrial ectopic activity or short-run atrial tachyarrhythmis, given the fact that each...
Show MoreGiven the fact that acute myocardial infarction(AMI)(1), left bundle branch block(LBBB)(2), and pulmonary embolism(PE), are all age-related disorders, the authors of the recent study correctly highlighted the importance of including PE in the differential diagnosis of the association of suspected AMI and LBBB(2). For the purpose of identifying those patients who are most likely to have AMI the authors proposed the use of serum troponin as a rule-in criterion during the first 3 hours of hospital admission . By implication the inclusion of PE in the differential diagnosis should be deferred for at least 3 hours, and only activated in patients who do not have a raised serum troponin level.
Show MoreHowever, in view of the fact that elevation in serum troponin may be a feature in the presentation of PE(4), and also in view of the fact that transient LBBB has been reported in a 59 year old patient with PE(5), the latter disorder should be included in the differential diagnosis of the association of acute coronary syndrome and LBBB. In the 59 year old patient who was reported with PE and LBBB, serial troponin levels were 0.38, 0.41, and 1.12 ng/ml(reference range 0-0.04)(5), arguably justifying early coronary angiography(2). That patient had neither pleuritic pain nor breathlessness to raise the index of suspicion for PE. Coronary angiography ruled out coronary artery occlusion, and helical computed tomography revealed extensive PE involving the main branches of both pul...
In the context of suspected cardiac implantable electronic device infection a fundamental flaw in transoesophageal echocardiography(TOE) is that this modality does not distinguish between infective and non infective masses situated on the electronic device lead. For example, in one study 25 patients who underwent TOE were shown to have either a lead vegetation(11 cases) or lead strands(13 cases) or both(1 case). Nevertheless, 18 of of those 25 patients proved, after exhaustive evaluation, to have no evidence of infection(1). According to a recent report, however, guided biopsy of a lead-associated mass, by means of a biotome, can facilitate the distinction between an infective versus non infective device-related mass. In Case 1 of that report an 80 year old woman with a pacemaker presented with mild leucocytosis in the setting of a recent dental procedure, but was afebrile. Transoesophageal echocardiography(TOE) disclosed a 1.6 X 1.0 cm mass on her right atrial lead. Using femoral access and fluoroscopic guidance the mass was biopsied under TOE guidance. The mass proved to be a thrombus with irregular fragments of soft tissue. The gram stain showed no polymorphonuclear cells and the tissue culture confirmed no growth. Case 2 in that report was a 29 year old man with an implantable cardioverter-defibrillator in the setting of intermittent fever and night sweats. TOE revealed a 2.9 cm X 1.2 mass encasing the device lead. A single blood culture grew a Propionib...
Show MoreNotwithstanding the high costs and lack of reimbursement associated with the use of positron emission tomography/computed tomography(PET/CT) in suspected cardiac implantable electronic device (CIED) infection(1), the ability of this modality to distinguish between infective and non infective vegetations is a powerful argument for its inclusion in the workup of suspected CIED. Evidence of the ability to make this distinction comes from two sources(2)(3). Firstly, in a retrospective study of 177 transoesophageal echocardiographic studies performed on 153 consecutive patients, a visible mass was observed on a device lead in 25 instances. In 11 studies this was a lead vegetation, in 13 instances only lead strands were seen, and in one instance a lead vegetation coexisted with a lead strand. Nevertheless, 18 of the 25 patients with lead-associated masses had no other evidence of infection. In that study the presence or absence of infection was adjudicated by three clinical investigators who independently reviewed all available clinical data without knowledge of the echocardiographic results(2). In another study, 63 consecutive patients(mean age 68.6) with suspected CIED were evaluated both by echocardiography(tranasthoracic and transoesophageal) and by PET/CT. Echocardiography was associated with a positive predictive value(PPV) of 83.3%, and a negative predictive value(NPV) of 69.2%. For PET/CT, PPV and NPV amounted to 100% and 93.9%, respectively(3). The additional ut...
Show MoreUnder the heading "Changes in kidney function during intercurrent illness"(1) mention must be made of the risk of acute kidney injury when nonsteroidal anti inflammatory drugs(NSAIDs) are prescribed for acute gout, the latter complication(the equivalent of "intercurrent illness") sometimes documented as a consequence of diuretic use in congestive heart failure(CHF)(2). Coprescription of NSAIDs, diuretics, and angiotensin converting enzyme inhibitors(or angiotensin receptor blockers), so-called triple therapy, is associated with increased risk of acute kidney injury(rate ratio 1.31, 95% Confidence Interval 1.12 to 1.53)(3). This was shown in a nested case-control study which enrolled patients in whom hypertension was the indication for prescription of diuretics and/or angiotensin converting enzyme inhibitors(or angiotensin receptor blockers)(3), but might be equally applicable in the context of CHF. Additionally, among CHF patients who have a drug regime which includes spironolactone, the use of NSAIDs might increase the risk of hyperkalaemia. The rationale is that NSAIDs "interfere with the stimulatory effect of prostaglandins on the release of renin"(4). The risk of hyperkalaemia may be compounded by concurrent use of beta adrenergic blocking agents(4).
Show MoreFor all the above reasons, NSAIDs should be contraindicated in CHF patients with gout. The recommended alternatives include colcichine(5) and intraarticuoar corticosteroids(6), resp...
Pages