Association between basic life support and survival in sports-related sudden cardiac arrest: a meta-analysis

AIMS

To evaluate the association of basic life support with survival after sports-related sudden cardiac arrest (SR-SCA).

METHODS AND RESULTS

In this systematic review and meta-analysis, a search of several databases from each database inception to 31 July 2021 without language restrictions was conducted. Studies were considered eligible if they evaluated one of three scenarios in patients with SR-SCA: (i) bystander presence, (ii) bystander cardiopulmonary resuscitation (CPR), or (iii) bystander automated external defibrillator (AED) use and provided information on survival. Risk of bias was evaluated using Risk of Bias in Non-randomized Studies of Interventions. The primary outcome was survival at the longest follow up. The meta-analysis was conducted using the random-effects model. The Grading of Recommendations Assessment, Development, and Evaluations (GRADE) approach was used to rate certainty in the evidence. In total, 28 non-randomized studies were included. The meta-analysis showed significant benefit on survival in all three groups: bystander presence [odds ratio (OR) 2.55, 95% confidence interval (CI) 1.48-4.37; I2 = 25%; 9 studies-988 patients], bystander CPR (OR 3.84, 95% CI 2.36-6.25; I2 = 54%; 23 studies-2523 patients), and bystander AED use (OR 5.25, 95% CI 3.58-7.70; I2 = 16%; 19 studies-1227 patients). The GRADE certainty of evidence was judged to be moderate.

CONCLUSION

In patients with SR-SCA, bystander presence, bystander CPR, and bystander AED use were significantly associated with survival. These results highlight the importance of witness intervention and encourage countries to develop their first aid training policy and AED installation in sport settings.

Genome-wide association analyses identify new Brugada syndrome risk loci and highlight a new mechanism of sodium channel regulation in disease susceptibility

Brugada syndrome (BrS) is a cardiac arrhythmia disorder associated with sudden death in young adults. With the exception of SCN5A, encoding the cardiac sodium channel Na_V1.5, susceptibility genes remain largely unknown. Here we performed a genome-wide association meta-analysis comprising 2,820 unrelated cases with BrS and 10,001 controls, and identified 21 association signals at 12 loci (10 new). Single nucleotide polymorphism (SNP)-heritability estimates indicate a strong polygenic influence. Polygenic risk score analyses based on the 21 susceptibility variants demonstrate varying cumulative contribution of common risk alleles among different patient subgroups, as well as genetic associations with cardiac electrical traits and disorders in the general population. The predominance of cardiac transcription factor loci indicates that transcriptional regulation is a key feature of BrS pathogenesis. Furthermore, functional studies conducted on MAPRE2, encoding the microtubule plus-end binding protein EB2, point to microtubule-related trafficking effects on Na_V1.5 expression as a new underlying molecular mechanism. Taken together, these findings broaden our understanding of the genetic architecture of BrS and provide new insights into its molecular underpinnings.

[Controversy. Screening for sports activity: con !]

Screening for sports activity: con! Far from the image of the high-level soccer player collapsing on the lawn in the middle of a match, undoubting an emotional impression covered regularly by the media and now part of our collective imagination, sudden death during sports has most commonly been observed among middle aged 'Sunday' athletes. The consistent media coverage on sudden cardiac death among young competitive athletes has provided the opportunity to draw public awareness of cardiac arrest in general, however, overall it is far from being a globally recognized public health issue eligible for an organized screening campaign.

Robustness and relevance of predictive score in sudden cardiac death for patients with Brugada syndrome

AIMS

Risk stratification of sudden cardiac arrest (SCA) in Brugada syndrome (Brs) remains the main challenge for physicians. Several scores have been suggested to improve risk stratification but never replicated. We aim to investigate the accuracy of the Brs risk scores.

METHODS AND RESULTS

A total of 1613 patients [mean age 45 ± 15 years, 69% male, 323 (20%) symptomatic] were prospectively enrolled from 1993 to 2016 in a multicentric database. All data described in the risk score were double reviewed for the study. Among them, all patients were evaluated with Shanghai score and 461 (29%) with Sieira score. After a mean follow-up of 6.5 ± 4.7 years, an arrhythmic event occurred in 75 (5%) patients including 16 SCA, 11 symptomatic ventricular arrhythmia, and 48 appropriate therapies. Predictive capacity of the Shanghai score (n = 1613) and the Sieira (n = 461) score was, respectively, estimated by an area under the curve of 0.73 (0.67-0.79) and 0.71 (0.61-0.81). Considering Sieira score, the event rate at 10 years was significantly higher with a score of 5 (26.4%) than with a score of 0 (0.9%) or 1 (1.1%) (P < 0.01). No statistical difference was found in intermediate-risk patients (score 2-4). The Shanghai score does not allow to better stratify the risk of SCA.

CONCLUSIONS

In the largest cohort of Brs patient ever described, risk scores do not allow stratifying the risk of arrhythmic event in intermediate-risk patient.

[Fighting against unexplained sudden death]

Sudden cardiac death, mostly related to ventricular arrhythmia, is a major public health issue, with still very poor survival at hospital discharge. Although coronary artery disease remains the leading cause, other etiologies should be systematically investigated. Exhaustive and standardized exploration is required to eventually offer specific therapeutics and management to the patient as well as his/her family members in case of inherited cardiac disease. Identification and establishing direct causality of the detected cardiac anomaly may remain challenging, underlying the need for a multidisciplinary and experimented team.

GENECHOC study: genetic markers of arrhythmic risk in heart failure

Background

Ventricular arrhythmic events are responsible for 50% of death in heart failure but no reliable predictive marker is known to discriminate patients at risk of fatal arrhythmia. Interestingly, familial predisposition has been reported suggesting a role of genetic factors.

Purpose

Identify genetic markers increasing the arrhythmic risk in heart failure population.

Method

We prospectively included heart failure patients with left ventricular ejection fraction (LVEF) under 35% and a cardioverter defibrillator in primary prevention in 22 French centres between 2009 and 2017. Patients were followed for 72 months and divided into two groups: cases with an arrhythmic event during follow-up and controls. A Genome Wide Association Study (GWAS) was done. Single Nucleotide Polymorphisms (SNPs) genotyping was performed on Affymetrix Axiom Precision Medicine Research Array plates. To complement the directly genotyped SNPs we performed large-scale imputation based on the Haplotype Reference Consortium European ancestry panel leading to a dataset of 7,5 million of SNPs.

Results

332 cases and 567 controls were included (86% men, mean age at implantation 52±11 years). 78% of patients had ischaemic cardiopathy, 20% had dilated cardiomyopathy. Mean LVEF was 27±5%. No statistical difference was found between cases and controls on clinical parameters, biological results, electrocardiographic measures. No locus shows genome-wide significant association (p&lt;5.10–8) on the GWAS analysis. However, 16 signals with a p-value between 5.10–8 and 5.10–5 were investigated. eQTL and chromatin conformation point to 35 genes with cardiac expression previously associated with heart failure, cardiomyopathies, cardiogenesis, arrhythmias and inflammation. Variants identified point to regulatory regions of the genome and may then propose a molecular mechanism predisposing patients to arrhythmias.

Conclusion

No locus raises genome-wide significance, but several signals with a nominal p-value point to relevant genes and pathways. Replication of the GWAS is ongoing on a cohort of 156 new patients with a less severe cardiopathy implanted with a cardioverter defibrillator in secondary prevention.

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): Nantes University Hospital

P5027Prognosis and evaluation of the risk markers of arrhythmia in a large population of Brugada syndrome patients

Introduction

Brugada syndrome (BrS) is an inherited arrhythmia syndrome with an increased risk of sudden cardiac death (SCD) despite a structurally normal heart. Many parameters have been suggested to be associated with the risk of ventricular arrhythmias, but only previous symptoms and spontaneous ECG pattern have been consistently associated with the risk of ventricular arrhythmia occurrence.

Objective

The aim of this study was to evaluate the association of these parameters with arrhythmic events in the largest cohort of BrS patients ever described.

Methods

Consecutive patients affected with BrS were recruited in a multicentric prospective registry in France (15 centers) between 1994 and 2016. Data were prospectively collected with an average follow-up of 6.5±4.7 years. ECGs were reviewed by 2 physicians blinded to clinical status.

Results

In this study, we enrolled a total of 1613 patients (mean age 45±15 years; 1119 males, 69%). At baseline, 462 patients (29%) were symptomatic (51 (3%) aborted SCD, 257 (16%) syncope). A spontaneous type 1 ECG pattern was present in 505 patients (31%). Implantable cardiac defibrillator was implanted in 477 patients (30%).

During the follow-up, 91 patients (6%) underwent arrhythmic events (16 SCD (10%), 48 appropriate ICD therapy (3%) and 27 ventricular arrhythmias (2%). Thirty-six patients (2%) died of non-arrhythmic causes. Mean age at the first event was 44±15 years.

In our cohort, event predictors were SCD (HR: 18.3; 95% CI: 11.2–29.8; p<0.0001), syncope (HR: 2.9; 95% CI: 1.8–4.9; p<0.0001), age >60 years (HR: 0.11; 95% CI: 0.032–0.377; p=0,0004), gender (HR: 2.96; 95% CI: 1.6–5.4; p=0.0005), spontaneous type 1 (HR: 2.14; 95% CI: 1.42–3.23; p=0.0003), type 1 ST elevation in peripheral ECG lead (HR: 3.6; 95% CI: 1.9–7.1; p=0,0001), fragmented QRS (HR: 3.37; 95% CI: 1.37–8.32; p=0,008), AvR sign (HR: 2.2; 95% CI: 1.4–3.8; p=0,0007), QRS >120ms in D2 lead (HR: 2.2; 95% CI: 1.4–3.6; p=0,001) and QRS >90ms in V6 (HR: 2.1; 95% CI: 1.3–3.3; p=0,001). All the others parameters including early repolarization pattern (ERP) and EPS were not predictor of events.

Conclusion

In the largest cohort of BrS patients ever described, we confirmed that symptoms, age, gender, spontaneous type 1, type 1 ST elevation in peripheral ECG lead, fragmented QRS, AvR sign, QRS >120ms in D2 and QRS >90ms in V6 are associated with arrhythmic events whereas ERP and EPS were not.