Background: To prevent sudden cardiac death (SCD) in patients with hypertrophic cardiomyopathy (HCM), the HCM Risk-SCD calculator and guideline recommendations are used to aid decision-making for implantable cardioverter defibrillator (ICD) implantation.
Objectives: The aim of this study was to assess the clinical profiles and occurrence of SCD by phenotypes of HCM and validate the performance of the current guidelines from a Japanese large-scale multicenter registry.
Methods: This was a retrospective, multicenter, observational, longitudinal, cohort study that enrolled 3611 consecutive patients with HCM. The primary endpoint was a composite of SCD or an equivalent event.
Results: The 5-year cumulative incidence of SCD events was markedly high in patients with ES-HCM defined by ejection fraction <50% (18.5%), following by mid-ventricular obstruction and non-obstructive HCM (6.9% and 4.7%). The 5-year cumulative incidence of SCD events for each recommendation class by the two guidelines were: the 2024 ACC/AHA; 23.8%, 7.2%, 5.7%, and 2.3%, and for class1, 2a, 2b, and 3, respectively; the 2023 ESC, 23.8%, 2.9%, 9.3%, and 2.6%, respectively. The 5-year risk was not well stratified between class 2a and 2b by the 2024 ACC/AHA (p=0.101) and the event rate was even reversed by the 2023 ESC guidelines (p=0.545).
Conclusions: Among the HCM phenotypes, the prognosis of patients with ES-HCM was markedly worse. The 2024 ACC/AHA and 2023 ESC guidelines well stratified the SCD risk in patients with HCM; the 2024 ACC/AHA seemed to better stratify SCD risk between class 2a and class 2b compared to the 2023 ESC.
Editors
JACC Heart Failure Editor-in-Chief
Biykem Bozkurt, MD, PhD, FACC
Deputy Editor
Akshay S. Desai, MD, MPH
JACC Heart Failure CME/MOC Editor
Kenneth A. Ellenbogen, MD
Author
Megan Pelter, MD
Important Dates
Date of Release: June 2, 2025
Term of Approval/Date of CME/MOC Expiration: June 1, 2026