Increasing evidence that risk scores underperform in predicting sudden death in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) remains the most common cause of sudden cardiac death (SCD) in young people, underscoring the need for accurate selection of patients for primary prevention implantable cardioverter-defibrillator (ICD) therapy.1 Since 2014, the European Society of Cardiology (ESC) has promoted a quantitative risk score, composed of seven disease-related features that can be imputed on a smart phone (ESC Risk Score App) to predict sudden death events over 5 years.2 The ESC risk score ascribes management recommendations for primary prevention ICDs based on whether a patient falls into one of three risk categories: low (<4%, ICD not indicated), intermediate (4%–6%, ICD could be considered) or high (≥6%, ICD should be considered). Of note, the ESC risk score excludes children and adolescent patients with HCM, a subgroup traditionally considered at particularly high risk for SCD. Prior investigations of this risk score have included only a small number of Asian patients with HCM2 3 and therefore the primary aim of the present Heart study by Choi et al ,4 was to determine the efficacy of the HCM Risk-SCD calculator in a cohort of Korean patients with HCM. In this observational cohort study, 730 Korean patients with HCM were followed for 4288 person-years for the primary endpoint of SCD events. Over the follow-up, 11 patients died suddenly and six experienced appropriate ICD shocks for ventricular tachyarrythmias, including seven patients with low ESC risk score, three with intermediate scores and six with high-risk scores. Of particular importance was the observation that …