The prehospital 12-lead electrocardiogram's effect on time to initiation of reperfusion therapy: a systematic review and meta-analysis of existing literature

doi:10.1016/j.ajem.2005.02.004

The American Journal of Emergency Medicine

Volume 23, Issue 3, May 2005, Pages 351-356

https://doi.org/10.1016/j.ajem.2005.02.004 Get rights and content

Abstract

The prehospital electrocardiogram (ECG) is becoming the standard of care of suspected cardiac chest pain. We evaluated the evidence regarding the prehospital ECG and sought to quantify the reduction in time to reperfusion therapy attributable to the prehospital ECG. We conducted a systematic review and analyzed studies that were conducted in emergency medical systems relevant to providers in the United States. The papers were limited to studies that reported original data that compared prehospital ECG to no prehospital ECG groups. Four studies containing 99 patients met the inclusion criteria. A meta-analysis of these studies revealed a difference of 24.7 (95% confidence interval, 16.7-32.7) minutes. Providers now have a quantified value of the prehospital ECG based on the best published evidence. In addition, this search showed a relatively low quality and quantity of research on the prehospital ECG.

Introduction

Several studies have shown that the prehospital 12-lead electrocardiogram (ECG) is accurate in identifying patients with acute myocardial infarction (AMI) and acute cardiac ischemia (ACI) [1], [2], [3]. Obtaining a prehospital ECG is becoming the standard of care [4], [5], and several emergency medical service (EMS) practice guidelines recommend the prehospital ECG [6]. Among many EMS providers, the prehospital ECG is considered an important procedure that improves patient care [7]. In our previous study, cardiologists and emergency physicians were shown to have positive attitudes about the usefulness and benefits of the prehospital ECG [8].

The American Heart Association gives the prehospital ECG a class 1 recommendation [9]. However, most of the data used to support this evidence-based recommendation derive from studies that do not apply to the current system of prehospital emergency care in the United States. For example, much of the data in published studies were generated in EMS systems that administered prehospital fibinolytics, whereas other studies either provided no original data, covered only theoretical time savings, reported on very few patients, or reported on patients who were admitted to services other than EDs. Finally, the only reference that showed a difference in mortality used historical cases as the control group.

The principal clinical benefit of the prehospital ECG is a reduction in the time from the beginning of cardiac symptoms to the initiation of inhospital reperfusion therapy. This study sought to analyze and quantify the existing research to determine if the prehospital ECG has reduced the time to treatment.

This systematic review and embedded meta-analysis were intended to locate all research in all languages that compared cardiac reperfusion times of patients who received a prehospital ECG with patients who did not receive a prehospital ECG. The principal measure of effect was the mean difference in minutes between control (no prehospital ECG) and treatment (prehospital ECG) inhospital reperfusion.

Section snippets

Search strategy

We conducted a search of multiple online databases in all languages and then reviewed the relevant articles that we found. After our preliminary search, we requested any gray literature (unpublished articles) from several authors who had published research related to the prehospital ECG. The databases that we searched were Medline, 1966 to January 2004, the Cumulative Index to Nursing and Allied Health Literature, 1982 to January 2004, the Cochrane Database Systematic Review, ACP Journal Club,

Search results

The original search strategy yielded 2129 publications with 1747 from Medline, 311 from Cumulative Index to Nursing and Allied Health Literature, and 71 from the Cochrane Evidence-Based Medicine Databases. From these, 615 papers were selected for additional investigation based on the relevance of their titles. The abstracts of the 615 papers were read for relevance, and 72 of these appeared to warrant complete retrieval and study. These 72 papers, in addition to several other topical expert

Discussion

We found that the best evidence, when combined, indicates that there is a 24.7-minute reduction in the time to inhospital reperfusion intervention associated with the prehospital ECG. However, with strict inclusion and exclusion criteria based on like-systems and comparable methodologies, there are only 4 published papers with a total of 99 patients. Thus, the evidence of the clinical benefits of the prehospital ECG is relatively weak.

The prehospital ECG likely reduces reperfusion times through

Conclusion

This meta-analysis provides the best-evidence determination of reduced time to reperfusion in AMI and ACI associated with the prehospital ECG. It has a number of implications for clinical care and future research. The time savings of the prehospital ECG in reducing time to reperfusion therapy for patients with ACI/AMI of approximately 25 minutes can now be used to estimate numbers of lives saved, benefits in quality life-years, reduction in morbidity, cost reductions, more efficient allocation

Acknowledgment

Funding was provided by the University of New Mexico Emergency Medical Services Academy.

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Prevalence and Predictors of Delay in Seeking Emergency Care in Patients Who Call 9-1-1 for Chest Pain
2019, Journal of Emergency Medicine
Delay in seeking medical treatment for suspected acute coronary syndrome can lead to negative patient outcomes.
Our aim was to evaluate the prevalence and predictors of delay in seeking care in high-risk chest pain patients with or without acute coronary syndrome (ACS).
This was a secondary analysis of an observational cohort study of patients transported by Emergency Medical Services for a chief complaint of chest pain. Important demographic and clinical characteristics were extracted from electronic health records. Two independent reviewers adjudicated the presence of ACS. Logistic regression was used to model the predictors of delay in seeking care.
The final sample included 743 patients (99% non-Hispanic). Overall, 24% presented > 12 h from onset of symptoms. Among those with ACS (n = 115), 14% presented > 12 h after onset of symptoms. Race, smoking, diabetes, and related symptoms were associated with delayed seeking behavior. In multivariate analysis, non-Caucasian race (black or others) was the only independent predictor of > 12 h delay in seeking care (odds ratio 1.4; 95% confidence interval 1.0–1.9).
One in four patients with chest pain, including 14% of those with ACS, wait more than 12 h before seeking care. Compared to non-blacks, black patients are 40% more likely to delay seeking care > 12 h.
Prehospital Acute ST-Elevation Myocardial Infarction Identification in San Diego: A Retrospective Analysis of the Effect of a New Software Algorithm
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Citation Excerpt :
The prehospital diagnosis of ST-elevation myocardial infarction (STEMI) leading to activation of the cardiac catheterization laboratory (CCL) is associated with reduced “door-to-balloon” time and reduced mortality (1–8).
A significant increase in false positive ST-elevation myocardial infarction (STEMI) electrocardiogram interpretations was noted after replacement of all of the City of San Diego's 110 monitor-defibrillator units with a new brand. These concerns were brought to the manufacturer and a revised interpretive algorithm was implemented.
This study evaluated the effects of a revised interpretation algorithm to identify STEMI when used by San Diego paramedics.
Data were reviewed 6 months before and 6 months after the introduction of a revised interpretation algorithm. True-positive and false-positive interpretations were identified. Factors contributing to an incorrect interpretation were assessed and patient demographics were collected.
A total of 372 (234 preimplementation, 138 postimplementation) cases met inclusion criteria. There was a significant reduction in false positive STEMI (150 preimplementation, 40 postimplementation; p < 0.001) after implementation. The most common factors resulting in false positive before implementation were right bundle branch block, left bundle branch block, and atrial fibrillation. The new algorithm corrected for these misinterpretations with most postimplementation false positives attributed to benign early repolarization and poor data quality. Subsequent follow-up at 10 months showed maintenance of the observed reduction in false positives.
This study shows that introducing a revised 12-lead interpretive algorithm resulted in a significant reduction in the number of false positive STEMI electrocardiogram interpretations in a large urban emergency medical services system. Rigorous testing and standardization of new interpretative software is recommended before introduction into a clinical setting to prevent issues resulting from inappropriate cardiac catheterization laboratory activations.
Association of Pre-hospital ECG Administration With Clinical Outcomes in ST-Segment Myocardial Infarction: A Systematic Review and Meta-analysis
2016, Canadian Journal of Cardiology
Citation Excerpt :
A number of reviews have been published regarding pre-hospital ECG use but most have focused on reperfusion time and did not consider long-term, patient-oriented outcomes. Brainard et al.,20 Morrison et al.,21 and Brown and Galloway22 all evaluated pre-hospital ECG in the context of fibrinolysis as a reperfusion strategy and included a small number of studies (4-8) in their analyses. Only Morrison et al. reported mortality outcomes and showed no survival benefit for pre-hospital ECG.
Delays in reperfusion for patients with myocardial ischemia leads to increased morbidity and mortality. The objective of this review was to identify, evaluate, and critically appraise the evidence on whether pre-hospital electrocardiography (ECG) reduces patient mortality and improves post—ST-segment myocardial infarction patient-oriented outcomes.
We searched PubMed/MEDLINE, EMBASE, and Cochrane Library (1990-2015) for controlled clinical studies. We also searched conference proceedings, trial registries, and reference lists of narrative and systematic reviews. Two reviewers independently identified and extracted data from studies that compared pre-hospital ECG with standard of care in patients with suspected myocardial infarction who underwent primary percutaneous coronary intervention. Internal validity was assessed using the Newcastle-Ottawa scale.
We screened 21,197 citations and included 63 unique studies (plus 22 companion publications). Most studies were of moderate quality. Pre-hospital ECG was associated with significantly fewer deaths (relative risk, 0.68; 95% confidence interval [CI], 0.63-0.74; 45 studies; 71,315 patients; I², 0%), reduced time to reperfusion (mean difference, −35.32 minutes; 95% CI, −44.02 to −26.61; 26 studies; 27,524 patients; I², 97%), shorter hospital stays (mean difference, −0.63 days; 95% CI, −1.05 to −0.20; 10 studies; 39,275 patients; I², 39%), and more patients had first medical contact to device time < 90 minutes than standard of care (relative risk, 1.77; 95% CI, 1.52-2.07; 11 studies; 20,991patients; I², 93%).
Use of pre-hospital ECG is associated with decreased mortality and overall better patient outcomes.
Les retards de reperfusion chez les patients atteints d’une ischémie myocardique mènent à l’augmentation de la morbidité et de la mortalité. L’objectif de cette revue était de déterminer, d’évaluer et d’apprécier de manière critique les données probantes de manière à savoir si l’électrocardiographie (ECG) préhospitalier réduit la mortalité chez les patients et améliore les résultats cliniques axés sur le patient ayant subi un infarctus du myocarde avec sus-décalage du segment ST.
Nous avons cherché des études comparatives dans PubMed/MEDLINE, EMBASE et la Bibliothèque Cochrane (1990-2015). Nous avons également cherché des procès-verbaux de conférences, des registres d’essais et des listes de référence de revues narratives et systématiques. Deux examinateurs ont indépendamment déterminé et extrait les données d’études qui comparaient l'ECG prehospitalier à la norme de soins des patients montrant une suspicion d’infarctus du myocarde qui subissaient une intervention coronarienne percutanée primaire. La validité interne était évaluée à l’aide de l’échelle Newcastle-Ottawa.
Nous avons sélectionné 21 197 citations et inclus 63 études distinctes (et en plus 22 publications complémentaires). La plupart des études étaient de qualité modérée. L’ECG préhospitalier était associé à une diminution significative du nombre de décès (risque relatif, 0,68; intervalle de confiance [IC] à 95 %, 0,63-0,74; 45 études; 71 315 patients; I², 0 %), à une réduction du temps de reperfusion (différence moyenne, −35,32 minutes; IC à 95 %, −44,02 à −26,61; 26 études; 27 524 patients; I², 97 %), à des séjours à l’hôpital plus courts (différence moyenne, −0,63 jour; IC à 95 %, −1,05 à −0,20; 10 études; 39 275 patients; I², 39 %), et un plus grand nombre de patients avaient un premier contact médical avant la mise en place du dispositif < 90 minutes comparativement à la norme de soins (risque relatif, 1,77; IC à 95 %, 1,52-2,07; 11 études; 20 991 patients; I², 93 %).
L’utilisation de l’ECG préhospitalier est associée à la diminution de la mortalité et à des résultats cliniques globalement meilleurs chez les patients.
False Activations for ST-Segment Elevation Myocardial Infarction
2016, Interventional Cardiology Clinics
Systematic review and meta-analysis of the benefits of out-of-hospital 12-lead ECG and advance notification in ST-segment elevation myocardial infarction patients
2014, Annals of Emergency Medicine
To present a review of out-of-hospital identification of ST-segment elevation myocardial infarction patients transported by emergency medical services with 12-lead ECG and advance notification versus standard or no cardiac monitoring.
EMBASE, PubMed, and the Cochrane Library were searched, using controlled vocabulary and keywords. Randomized controlled trials and observational studies were included. Outcomes included short-term mortality (≤30 days), door-to-balloon/needle time and/or first medical contact–to-balloon/needle time. Pooled estimates were determined, where appropriate. Results were stratified by percutaneous coronary intervention or fibrinolysis.
The search yielded 1,857 citations, of which 68 full-texts were reviewed and 16 studies met the final criteria: 15 included data on percutaneous coronary intervention and 3 on fibrinolysis (2 included both). Where percutaneous coronary intervention was performed, out-of-hospital 12-lead ECG and advance notification was associated with a 39% reduction in short-term mortality (8 studies; n=6,339; risk ratio 0.61; 95% confidence interval 0.42 to 0.89; P=.01; I²=30%) compared with standard or no cardiac monitoring. Where fibrinolysis was performed, out-of-hospital 12-lead ECG and advance notification was associated with a 29% reduction in short-term mortality (1 study; n=17,026; risk ratio 0.71; 95% confidence interval 0.54 to 0.93; P=.01). First medical contact–to-balloon, door-to-balloon, and door-to-needle times were consistently reduced, though large heterogeneity generally precluded pooling.
The present study adds to previous reviews by identifying and appraising the strength and quality of a larger body of evidence. Out-of-hospital identification with 12-lead ECG and aadvance notification was found to be associated with reductions in short-term mortality and first medical contact–to-balloon, door-to-balloon, and door-to-needle time.
ECG signs of acute myocardial ischemia in the prehospital setting of a suspected acute coronary syndrome and its association with outcomes
2014, American Journal of Emergency Medicine
The aims of this study were (a) to determine the prehospital prevalence of electrocardiographic (ECG) signs of acute myocardial ischemia in patients with suspected acute coronary syndrome and (b) to describe the relationships between the various ECG patterns and the diagnosis of acute myocardial infarction (AMI) and outcomes.
Prospective cohort study using data from an interventional trial in acute chest pain patients transported by the emergency medical services. These patients were classified into 3 groups: patients with ECG showing signs of acute myocardial ischemia, patients with ECG showing other abnormal changes (bundle-branch block, pacemaker rhythm, Q-wave or T-wave inversion) and patients without significant pathologic findings. All P values are age-adjusted.
Among 1546 patients, 312 (20%) had ECG signs of acute myocardial ischemia. Of them, 57% had a final diagnosis of AMI versus 26% of those with other abnormal ECGs and 12% of those with ECG without significant pathologic findings (P < .0001). In all, 53% of all AMI cases involved patients without ECG signs of acute myocardial ischemia. Although ECG signs of acute myocardial ischemia predicted heart failure and ventricular tachyarrhythmias both prior to and after hospital admission, there was no significant difference in 30-day mortality between the 3 patient groups (4.3%, 3.7%, and 1.2%, respectively, P = .11).
Among patients with a clinical suspicion of AMI in the prehospital setting, the prevalence of ECG signs suggesting AMI was low, as was the ability to identify AMI patients using ECG findings only. We therefore need better instruments in the prehospital triage of patients with acute chest pain.

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ReviewsThe prehospital 12-lead electrocardiogram's effect on time to initiation of reperfusion therapy: a systematic review and meta-analysis of existing literature

Abstract

Introduction

Section snippets

Search strategy

Search results

Discussion

Conclusion

Acknowledgment

Ann Emerg Med

Ann Emerg Med

Emerg Med Clin North America

Prehosp Emerg Care

Am Heart J

Am J Emerg Med

Am J Cardiol

Ann Emerg Med

Am J Emerg Med

Am J Emerg Med

Am J Cardiol

J Am Coll Cardiol

Lancet

Reviews
The prehospital 12-lead electrocardiogram's effect on time to initiation of reperfusion therapy: a systematic review and meta-analysis of existing literature