Heart Int. 2026 Jun 2;20(1):20-34. doi: 10.17925/HI.2026.20.1.3. eCollection 2026.
ABSTRACT
BACKGROUND: Sudden cardiac arrest (SCA) in young adults (18-40 years) is rare but devastating, often occurring without prior symptoms. It often occurs in the absence of preceding symptoms or known structural heart disease. A comprehensive and systematic evaluation of its multifactorial aetiology, diagnostic challenges and preventive strategies is fundamental to reducing morbidity and mortality in this population.
OBJECTIVE: This systematic review aims to comprehensively evaluate the epidemiology, underlying aetiologies, associated risk factors, diagnostic approaches and preventive strategies for SCA in adults aged 18-40 years.
METHODS: PubMed, Scopus, Embase, Web of Science and Google Scholar were searched from January 2015 to June 2025. Eligible studies examined aetiologic mechanisms, screening strategies, clinical outcomes or public health interventions targeting the prevention, detection or management of SCA in individuals aged 18-40 years. Study quality was assessed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 checklist, the Risk of Bias in Nonrandomized Studies of Exposures (ROBINS-E), A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2) and the Newcastle-Ottawa Scale (NOS).
RESULTS: Of 3,000 records identified through the literature search, 55 studies met the inclusion criteria. The reported incidence of SCA among young adults ranged from 1 to 2 per 100,000 person-years in Western countries, with higher incidence rates observed in Asian populations. Structural cardiomyopathies were the predominant aetiologies, most notably hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy. These were followed by inherited channelopathies, including long QT syndrome, Brugada syndrome and catecholaminergic polymorphic ventricular tachycardia, as well as acquired conditions such as myocarditis and substance-related cardiac toxicity involving cocaine, amphetamines and anabolic steroids. Additional risk factors included systemic comorbidities, particularly sarcoidosis, chronic kidney disease and autonomic dysfunction. Diagnostic evaluation most frequently incorporated electrocardiography, transthoracic echocardiography, cardiac magnetic resonance imaging and genetic testing. Survival following out-of-hospital cardiac arrest was significantly improved in settings with prompt bystander cardiopulmonary resuscitation, widespread availability of automated external defibrillators and the implementation of community-based education initiatives.
CONCLUSION: Targeted screening strategies, improved access to advanced diagnostic modalities and population-level community interventions are essential for reducing the burden of SCA among young adult individuals. Further prospective research is warranted to enhance risk stratification and optimize prevention strategies in this high-impact population.
PMID:42293057 | PMC:PMC13262017 | DOI:10.17925/HI.2026.20.1.3