Abstract P556: Temporal and Global Trends of the Incidence of Sudden Cardiac Death in Hypertrophic Cardiomyopathy: A Meta-Analysis

Introduction: Since hypertrophic cardiomyopathy(HCM) initial description, sudden cardiac death (SCD) has been the most feared complication of HCM. Hypothesis: Temporal, geographical, and age-related trends of SCD rates in HCM have drastically decreased over time. Methods: Databases were systematically searched to Nov 2021 for studies reporting on SCD event rates in HCM. Patients with SCD equivalents (appropriate ICD shocks and non-fatal SCD) were excluded. Random-e!ects model was utilized to pool study estimates calculating the overall incidence rates(IR) for each time-era, geographical region, and age-group. We analyzed 2 eras (before vs. after 2000, following implementation of ICD in HCM). Following 2000, 5-year intervals were used to reflect the temporal change in SCD. Results: 98 studies(N=70,510patients and 431,407patient-years) met inclusion criteria. Overall rate of HCM SCD was 0.43%/year (95% CI: 0.37-0.50%; I2=75%; SCD events:1,938; person-years of follow-up: 408,715), with young patients(<18 years) demonstrating a>2-fold-risk for SCD vs. adults(18- 60years) (IR:1.09%; 95% CI: 0.69-1.73% vs. IR: 0.43%; 95% CI: 0.37-0.50%)(P-value for subgroup di!erences:<0.01). Contemporary SCD rates from 2015-present were 0.32%/year; significantly lower compared to 2000 or earlier (IR: 0.32%; 95% CI:0.20-0.52%, vs. IR: 0.73%; 95% CI:0.53-1.02%,respectively). Reported HCM-SCD rates were lowest in North America (IR: 0.28%;95% CI:0.18-0.43%) and highest in Asia(IR: 0.67%; 95% CI:0.54-0.84%). Conclusions: Contemporary HCM-related SCD are low (0.32%/year) representing a 2-fold decrease compared to prior treatment eras, with young HCM patients at the highest risk. SCD risk stratification maturation and primary prevention ICD application are likely responsible for the notable decline in SCD trends. Moreover, worldwide geographical disparities in SCD was evident, underscoring the need to increase access to SCD prevention for all HCM patients.