Tools for risk stratification of sudden cardiac death: A review of the literature in different patient populations

While various modalities to determine risk of sudden cardiac death (SCD) have been reported in clinical studies, currently reduced left ventricular ejection fraction remains the cornerstone of SCD risk stratification. However, the absolute burden of SCD is greatest amongst populations without known cardiac disease. In this review, we summarize the evidence behind current guidelines for implantable cardioverter defibrillator (ICD) use for the prevention of SCD in patients with ischemic heart disease (IHD). We also evaluate the evidence for risk stratification tools beyond clinical guidelines in the general population, patients with IHD, and patients with other known or suspected medical conditions.     

Cardioverter-defibrillator reduces mortality risk in eligible ischemic and non-ischemic cardiomyopathy patients: Sub-analysis of the multi-center Improve SCA study

Background & ObjectiveDespite the burden of sudden cardiac arrest (SCA) worldwide, implantable cardioverter-defibrillators (ICDs) are underutilized, particularly in Asia, Latin America, Eastern Europe, the Middle East, and Africa. The Improve SCA trial demonstrated that primary prevention (PP) patients in these regions benefit from an ICD or a cardiac resynchronization therapy defibrillator (CRT-D). We aimed to compare the rate of device therapy and mortality among ischemic and non-ischemic cardiomyopathy (ICM and NICM) PP patients who met guideline indications for ICD therapy and had an ICD/CRT-D implanted.MethodsImprove SCA was a prospective, non-randomized, non-blinded multicenter trial that enrolled patients from the above-mentioned regions. All-cause mortality and device therapy were examined by cardiomyopathy (ICM vs NICM) and implantation status. Cox proportional hazards methods were used, adjusting for factors affecting mortality risk.ResultsOf 1848 PP NICM patients, 1007 (54.5%) received ICD/CRT-D, while 303 of 581 (52.1%) PP ICM patients received an ICD/CRT-D. The all-cause mortality rate at 3 years for NICM patients with and without an ICD/CRT-D was 13.1% and 18.3%, respectively (HR 0.51, 95% CI 0.38–0.68, p < 0.001). Similarly, all-cause mortality at 3 years in ICM patients was 13.8% in those with a device and 19.9% in those without an ICD/CRT-D (HR 0.54, 95% CI 0.33–.0.88, p = 0.011). The time to first device therapy, time to first shock, and time to first antitachycardia pacing (ATP) therapy were not significantly different between groups (p ≥ 0.263).ConclusionsIn this large data set of patients with a guideline-based PP ICD indication, defibrillator device implantation conferred a significant mortality benefit in both NICM and ICM patients. The rate of appropriate device therapy was also similar in both groups.Clinical trial registrationClinicalTrials.gov ID: NCT02099721.     

La mort subite cardiaque chez la femme,registre du nord de la Tunisie

BackgroundSudden cardiac death is a major public health problem. Epidemiological and clinical differences according to gender have been described in sudden cardiac death. The aim of this study was to examine the gender differences between autopsy findings and circumstance of occurrence associated with sudden cardiac death.MethodsWe prospectively collected epidemiological and autopsy data of victims of sudden cardiac death occurring in the northern governorates of Tunisia between January 2013 and December 2019. Symptoms preceding death, circadian, weekly and seasonal variations of sudden death were also analyzed.ResultsThe study population included 1834 men and 468 women with a mean age of 56.5 ± 14.2 years. All cardiovascular risk factors except smoking were significantly more frequent among women but ischemic heart disease was the most common cause of death in men (51.3 %, versus 28 %, P < 0.001). Women were more likely to have a negative macroscopic autopsy than men (34 % versus 23.6 %, P < 0.001). Chest pain preceding sudden death was more frequent in male (24 % versus 13.2 %, P < 0.001). In contrast, women were more likely to have dyspnea (8.1 % versus 15.6 %, P < 0.001). Sudden death in women occurred indoors more often than in men (63.9 % versus 54.5 %, P < 0.001) and also more often during night (midnight to 6 am). We also recorded an excess cardiac mortality in winter in both sexes.ConclusionsWomen had considerably more cardiovascular risk factors and more commonly negative macroscopic autopsy. Death occurred indoors and during night more often than in men.     

室性心律失常的研究：创新铸就超越

室性心律失常危害身心健康,尤其是室性心动过速（室速）和心室颤动（室颤）更可直接导致心脏性猝死。21世纪的前10年,国内外在室性心律失常的机制和防治研究中均取得重要进展。本期杂志刊登一组文章,涉及医院内室颤的救治、室速和室颤的机制、药物治疗、射频消融治疗、植入型心律转复除颤器（ICD）的应用等内容。所刊文章或许有诸多不足,并不完美,但锐意创新为其共同特点。     

Electrocardiogram as a screening tool in the general population: A strategic review

Sudden cardiac death (SCD) is a major public health concern, accounting for 400,000 deaths in the US each year. Clinical and autopsy studies have consistently demonstrated a predominant, common pathophysiology in Western populations, showing that the most common electrophysiological mechanism of SCD is ventricular fibrillation, and the most common pathologic substrate is coronary heart disease (CHD). In about half of SCD cases, death is the first clinical manifestation of CHD. Yet risk factors of SCD early in the natural history of conditions predisposing SCD have not been fully identified, and SCD risk stratification strategy in the general population has not been developed. ECG is an easily available, non-expensive and non-invasive tool, which carries valuable information on electrophysiological properties of the heart. However, traditional analysis of ECG includes very limited assessment of the arrhythmogenic substrate. In this review rationale for development of ECG SCD risk score for screening in the general population is discussed.     

老年急性心肌梗塞晚发心原性猝死的临床及病理分析

为了分析老年急性心肌梗塞（ＡＭＩ）２周后发生心原性猝死的原因，本文总结了１２例心原性猝死患者，其中６例进行了尸检。认为无论是持续心肌电不稳定所致的原发性室颤，还是梗塞早期的全并症，如休克、心功能不全，梗塞后心绞痛引起的继发性室颤均为晚发心原性猝死的常见原因。尸检结果表明，老年ＡＭＩ晚发心原性猝死多发生于冠脉病变严重者。对于室颤高危患者应采取积极预防措施，如抗心律失常药物的合理应用、改善冠脉循环及改     

53例心原性猝死的临床病理分析

目的 探讨心原性猝死(SCD)的临床特点、病理基础及致死因素,为防治SCD提供线索.方法 回顾性分析我院53例SCD的临床病理资料.结果 53例SCD患者中,冠心病猝死36例,主动脉夹层动脉瘤破裂者7例,心肌炎7例,心肌病3例.冠心病猝死36例中,陈旧性心肌梗塞(OMI)23例,其中合并急性心肌梗塞(AMI)18例,单纯AMI7例(致心脏破裂4例),心肌缺血6例.尸检发现冠状动脉粥样硬化性狭窄Ⅳ级31例,呈多支Ⅳ级病变者24例.结论　SCD病程短骤、凶险,以老年男性多见,冠心病占首位.其次为主动脉夹层动脉瘤破裂、心肌炎、心肌病.冠状动脉多支重度粥样硬化性狭窄是重要的病理基础.尽早防治冠心病,改善心肌供血是预防SCD的根本措施.长期监测动脉瘤的发展而对有增大或濒临破裂征象者立即手术,也是减少SCD的有效措施.SCD随时随地可以发生,因此普及现场心肺复苏抢救知识及建立完善急救系统十分必要.     

Mort subite,en quête d’une explication

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.