Hypertrophic Cardiomyopathy's Decline as a Cause of Sudden Death in the Young: Global and National Insights.

Abstract

Background & Objective: Hypertrophic cardiomyopathy (HCM) has been reported as a leading cause of sudden cardiac death (SCD) in the young but appears less common in contemporary cohorts of young SCD. This research aimed to determine if HCM is a common cause of SCD in the young and whether this has changed over time. Method(s): We analysed three national databases, the National Echo Database Australia (NEDA), Centre for Disease Control Wide-ranging Online Data for Epidemiologic Research (CDC-WONDER) and the National Coronial Information System of Australia (NCIS) to determine incidence of SCD due to HCM in <=35 years old from 1999-2017. Sub-analyses assessed for differences in sex and obstructive and non-obstructive HCM phenotypes. Result(s): NEDA: Of 40,737 individual echocardiograms 2005-2017, 868 exhibited the HCM phenotype (2.1%). 1,444 patients died by the census date, of which seven deaths were attributable to HCM (0.48%). CDC-WONDER: 41% reduction in HCM related mortality/million people across 1999-2016 (p<.0001). Similar reduction was seen when stratified for age, sex and non-obstructive/obstructive HCM phenotype. NCIS: 36% reduction in HCM-related SCD was observed between 2001-2010 and 2011-2016 periods (4.41% vs 2.72%, p=0.049 respectively). Conclusion(s): HCM rarely causes SCD and accounts for <5% of SCD in the young. Rates of HCM-related SCD have been decreasing over the last two decades. Improved survival likely relates to improved case detection and medical management.Copyright � 2024