Endpoint Selection in Randomized Clinical Trials for Hypertrophic Cardiomyopathy.

Abstract

Randomized clinical trials (RCTs) for hypertrophic cardiomyopathy (HCM) have long been challenging caused by the condition's rarity, low event rates, and diverse clinical presentations. However, recent advances in targeted therapies have sparked increased interest in HCM research. Despite this, designing effective RCTs remains complex, particularly in identifying clinically meaningful endpoints. HCM, often linked to sequence variation in sarcomeric protein genes like MYH7 and MYBPC3, exhibits varied phenotypic expressions that influence disease progression and treatment responses. This genetic variability underscores the need for personalized approaches in clinical trials. Emerging gene therapies, such as CRISPR/Cas9, show promise in addressing these genetic factors. A major challenge in HCM RCTs is ensuring that endpoints are both statistically and clinically significant, given issues like test-retest variability and missing data. Primary endpoints often focus on symptom relief and functional improvement, while secondary and exploratory endpoints provide broader insights into treatment effects. Regulatory authorities are increasingly open to a wider range of endpoints, including patient-reported outcomes and functional measures, although the cost-risk balance is crucial, especially for high-risk interventions. Future HCM RCTs may incorporate hard clinical endpoints such as heart failure hospitalization, atrial fibrillation recurrence, and all-cause mortality, offering a more comprehensive evaluation of treatment efficacy. Integrating genetic insights and advanced technologies will be essential to improving trial design and enhancing patient outcomes in HCM.