eLetters

118 e-Letters

published between 2016 and 2019

  • Machine learning to predict death after cardiac surgery in patients with infective endacarditis: Why not! But, where are the (big) data please?

    The study of Olmos et al., on prediction of in-hospital mortality in patients with active infective endocarditis undergoing cardiac surgery, is of great interest.1
    Indeed, this topic is fascinating because it is complicated to make a choice in so dramatic and not so rare situation.
    To help with this decision-making, the authors proposed a model for predicting hospital mortality: a classic multivariate logistic regression model.
    However, the editorial published with this article evokes in the title a new method: machine learning.2 Machine learning, which is a field of artificial intelligence, has already been used for predicting hospital mortality after elective cardiac surgery.3 This study aimed at comparing a machine learning model, a classic logistic regression model and EuroSCORE II on a cohort including 6,520 patients. The comparison of these models was based on ROC curves and decision curve analysis (DCA).4 Whatever the method of comparison, machine learning model was more accurate than other models.
    Our experience in this area probably allows us to make some comments on this editorial. Considering, the increase of studies comparing machine learning with logistic regression, it is now known that supervised machine learning algorithms improve the prediction of post-operative mortality. However, the size of the cohort used in the present study makes it difficult to apply machine learning algorithms. Indeed, this cohort comprised 671 patients who...

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  • Older Chinese patients will benefit more from treatment for erectile dysfunction

    We read with great interest this paper which demonstrated erectile dysfunction (ED), not only as a preclinical predictor of cardiovascular disease (CVD), treatment for ED. But also has a role in a reduced mortality and heart failure hospitalization1.However, a multi-country and region population-based survey indicated that the majority of Asian men have never sought treatment for ED because of cultural factors or sexual conservatism2.
    Unfortunately, this situation is more serious in China. A multi-center investigation of 3327 subjects showed that although the proportion of severe cases (IIEF<8) among the Chinese elderly is the highest in all age groups, most elderly men are reluctant to visit the hospital just for the loss of erectile function (EF). They consider the loss of libido and EF with increasing age to be a natural process of aging3. Moreover, even the old men who seek help for ED were more concerned about the side effects of Western medicine (e.g., PDE5i); only a few of them (19%) used Western medicine as the first choice4. Furthermore, Chinese physicians seldom ask patients about their sexual health during routine consultations, their neglect of the health education about ED also aggravated this vicious circle2, 4.
    Hence, there is a substantial need for promoting Andersson et al 's 1 findings on health education of elderly ED patients in China. The improved awareness and cultural factors would lead more Chinese elderly to visit the hospi...

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  • Is traumatic intracranial hemorrhage a specific risk factor of atrial fibrillation ?

    We read the study of Wei-Shiang Lin et al.[1] with a great interest. In their large-scale cohort retrospective study, they found that traumatic intracranial hemorrhage was associated with an increased risk of atrial fibrillation (AF) and hypothesized that inflammation and/or secondary cardiac insult due to the traumatic brain injury (TBI) may cause AF. Nevertheless, several points should be discussed. First, acute inflammation is well-known to be related to AF in trauma patients. The risk of new-onset AF is reasonably expected to occur at the acute phase following the trauma. This point has already been previously demonstrated to occur during the days following cardiac surgery or septic shock onset.[2] In the same way, cardiac insult occurs at the very early phase of TBI and the consecutive cardiac systolic dysfunction was reported to be reversible within the first week after the trauma. [3] In this perspective, how to explain that the risk of AF persists one year after the trauma? It would be very helpful if the authors could provide data on the delay between the day of trauma and the day of new-onset AF. Furthermore, inflammation and cardiac dysfunction are related to the TBI severity and it would be valuable to know whether the more severe TBI patients are more prone to develop AF than mild or moderate TBI. Finally, in their statistical model, the authors have taken into account comorbidities which are also known to favor AF. But others factors, such as sepsis and relat...

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  • Drowning in a 48-year-old man

    Sir,

    We congratulate McDowell et al. on their educational and interesting case report.1 However, we would like to comment on their use of the term ‘near-drowning’. This, and other confusing and older terms which caused inconsistencies in the literature, have been abandoned by organisations such as the International Liaison Committee on Resuscitation (ILCOR) and the World Health Organisation (WHO) who recommend a more structured and clearer way of reporting drowning incidents.2,3 For several years now, drowning has been defined as ‘a process resulting in primary respiratory impairment from submersion/immersion in a liquid medium. Implicit in this definition is that a liquid/air interface is present at the entrance of the victim’s airway, preventing the victim from breathing air. The victim may live or die after this process, but whatever the outcome, he or she has been involved in a drowning incident’. 2,3 We would thus recommend that the authors and readers of your journal follow ILCOR and WHO recommendations, and simply use the term ‘drowning’ irrespective of the patient outcome. While this may seem pedantic, we do believe that it will assist with standardisation in drowning research and literature.

    References

    1. McDowell K, Carrick D, Weir R. Heart Published Online First: 18 may 2017. doi:10.1136/heartjnl-2016-311043.
    2. Idris AH, Berg RA, Bierens J, Bossaert L, Branche CM, Gabrielli A, Graves SA, Handley AJ, Hoelle R, Morley PT, Papa L, Pepe...

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  • Moderate Sedation in Cardiac Electrophysiology Laboratory: a retrospective safety analysis

    Sawhney et al. reported that nurse-led, physician-directed moderate sedation during cardiac electrophysiology procedures is safe (1). All of the patients undergoing cardiac electrophysiological (EP) procedures and cardiac implantable electronic device (CIED) implantation during the last 12 years were moderately sedated. Since this study is a retrospective study, we could not comprehend why all patients were sedated despite the fact that routine sedation during all cardiac EP procedures and all CIED implantation is not recommended.
    Moreover, as mentioned in the article, sedation is a continuum and it is not always possible to predict how individual patients will respond. Therefore, a gradual increase of doses of the sedatives during sedation may be needed which may possibly increase the procedure duration. Did authors ascertain any prolongation of the procedures due to sedative administration?
    Furthermore, sedation may diminish arrythmia induction during EP procedures, particularly in patients with catecholamine-sensitive ventricular tachycardias (2). Did authors have any data questioning this issue?
    As a conclusion, the aim of sedation is to diminish the anxiety and to relieve the pain during the procedure. Therefore, using moderate sedation selectively in patients with anxiety or hyperalgesia may be more practical and rational rather than its routine use due to the fact that as mentioned in the article, researches and audit demonstrate continued avoidabl...

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  • Chocolate intake and risk of atrial fibrillation

    Chocolate intake and risk of atrial fibrillation

    Dear Editor,

    We have read with great interest the paper “Chocolate intake and risk of clinically apparent atrial
    fibrillation: the Danish Diet, Cancer, and Health Study” by Elizabeth Mostofsky and coworkers [1] and we found their conclusion of importance with a view to clinical prevention.

    With reference to the findings reported in the paper, we would like to make the following contribution to the discussion. In a recent analysis performed on 650 healthy women in pre-menopausal age (age range 45-54 years) chocolate intake was higher in women in the low quartile of adherence to Mediterranean Diet (low Med Score). This subgroup of women showed a lower ABI index compared to women with higher Med Score. The analysis of sources of antioxidants showed a greater intake from fruit and vegetables in the higher quartiles of Med Score. Coffee and tea were similarly distributed among the quartiles of Med Score [2]. Analysis from diet recall had the major limitation of missing data regarding out-of-mealtime snacking and drinking.
    In Mediterranean countries, wine is a strong antioxidant source and the synergistic effect of drinking wine during meals and antioxidant bioavailability is well known. We clearly understand that nutritional habits in Northern Europe differ from Mediterranean ones. However, we would like to underline that in a Mediterranean lifestyle characterized by high intake of antioxidants,...

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  • Does antibiotic prophylaxis really prevent streptococci infective endocarditis?

    To the Editor,
    We read with interest the work presented by Cahill et al. [1] in which the authors evaluate the impact of antibiotic prophylaxis to prevent bacteremia and infective endocarditis in patients undergoing dental procedures. The analysis was performed based on 36 studies, including 21 bacteremia studies, five case controls and cohort studies, and 10 time trend studies.
    It is generally well established that dental cares cause bacteremia, and that most are due to streptococcal strains [1,2]. It is, consequently, reasonable to think that prescribing antibiotics before dental cares decreases the incidence of such bacteremia. Globally, the discordant results between the different kinds of studies analyzed in the paper by Cahill et al. [1] are clearly insufficient to conclude that antibiotic prophylaxis prevents bacteremia due to streptococci. In our view, this observation can be explained by the fact that dental care is not the only cause of streptococcal bacteremia. Indeed, such bacteremia are extremely common, and it has been demonstrated that they can occur after chewing and after brushing in patients with periodontitis (cumulatively in 25% and 20% of cases, respectively) [2]. It is, therefore, fairly unlikely that bacteremias due to dental cares are more responsible for endocarditis than other kinds of bacteremias. In practice, this implies that the only reasonable antibiotic prophylaxis to prevent almost every bacteremia due to oral streptococci wou...

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  • The true value of the NICE guidance

    We read with interest the Editorial on the recently updated National Institute for Health and Care Excellence (NICE) guidance for the assessment of suspected stable angina (1). The authors raise some salient points regarding the importance of careful history taking, the vexed question of the exercise ECG and the relative merits of the myriad non-invasive tests for diagnosing coronary artery disease (CAD). However, we believe they have adopted an unnecessarily alarmist tone in their criticisms and feel obliged to respond to several issues.
    Although they suggest that the assessment of pretest probability (PTP) has been disregarded, this process has merely been made implicit rather than explicit. The guidelines emphasise the pivotal importance of the clinical history and, in the setting of suspected angina, the nature of the presenting symptoms is the dominant predictor of CAD. Existing risk tables (2) show that either typical or atypical angina essentially guarantees a PTP of CAD ≥ 10%, the threshold warranting further investigation in the earlier NICE guideline. The residual clinical risk seen in patients with non-anginal symptoms is best addressed through cardiovascular screening approaches with an emphasis of lifestyle modification and primary prevention.
    Second, in arguing against the cost-effectiveness of the new approach, the authors imply that NICE are recommending “universal CTCA” which is incorrect. Non-anginal chest pain occurs in 40-60% of patients pre...

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  • Liver injury with direct-acting anticoagulants: has the fog cleared?

    To the Editor,
    The timely retrospective US cohort study by Alonso et al.1 assessed the risk of hospitalisations for liver injury after initiation of oral anticoagulation in patients with non-valvular atrial fibrillation, an unresolved safety issue so far.
    This study has key merits. First, it demonstrates the importance of conducting analytical research following safety signals emerging from spontaneous reporting systems2, to confirm or refute the drug-related hypothesis; this allows actual risk assessment and avoids unnecessary alarm, sometimes generated by pharmacovigilance analyses which do not recognize the limits of detected signals.
    Second, it provides a significant contribution to the debate on targeted patients’ selection when prescribing DOACs. In fact, the authors found that hospitalization rates for liver injury were lower among DOAC initiators as compared to patients starting warfarin, with rivaroxaban and dabigatran associated with highest and lowest risk, respectively. They conclude that “dabigatran may be considered a safer option” in patients susceptible of liver complications. In this vulnerable population, our proposal when initiating DOAC administration is to early monitor hepatic enzymes (i.e., within the first month of therapy) and, subsequently, on a yearly basis, especially for rivaroxaban users.3
    Although this study contributes to allay concern on the hepatotoxicity potential of DOACs, a residual aspect deserves attention. The...

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  • Cautious anticoagulation strategy in patients with dialysis-requiring end-stage kidney disease.
    Jonathan M Behar

    We read with interest this manuscript which demonstrated in a large clinical registry that patients with chronic kidney disease with indications for anticoagulation were often treated sub-therapeutically (1). A more aggressive approach was therefore advocated.

    We would like to point out that, while this study should be commended for including a large number of patients, it did not show data on the key clinical...

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