Genotype predicts heart failure independent of left ventricular ejection fraction and NT-proBNP levels in hypertrophic cardiomyopathy

Abstract Background/Introduction Hypertrophic cardiomyopathy (HCM) is a myocardial disease associated with progression to heart failure. In around 40% of cases, the disease is caused by variants in genes encoding sarcomere proteins. Purpose To evaluate the role of genotype in predicting heart failure (HF) outcomes. Methods In this observational single-centre cohort study, consecutive patients with HCM were assessed for heart failure clinically stratified by genetic status into genotype-elusive which included those with no significant variants (G-) or variants of unknown significance (VUS) and genotype-positive (G+) with pathogenic/likely pathogenic (LP/P) variants. Heart failure endpoint was defined as left ventricular assist device implantation, heart transplantation or heart-failure-related death. The incidence of HF endpoint was compared between genotypes during follow-up using a time-to-event analysis. Results 474 patients (50.9 ±14.5 years, 67.3 males) with HCM (25% with left ventricular (LV) outflow obstruction) were followed for 10.9 years (IQR 5.1-13.5). G+ LP/P patients (201/474 (42.4%)) were younger (45.8. ±14.0 years) compared to G- (225/474 (47.5%), 55.2 ±13.4 years) and VUS (48/474 (10.1%), 52.0 ± 15 years); 29/474 (6.1%) reached the heart failure endpoint. The incidence of heart failure endpoints was 12.4% (25/201) in the G+ LP/P group compared to 1.5% (4/273) in the gene elusive group. A multivariate Cox proportional hazards model including NT-proBNP and LV ejection fraction (LVEF) and genetic status showed that G+ LP/P was associated with increased risk of heart failure outcomes (HR: 5.11, 95% CI: 1.43–18.25, p=0.012). Every 100-unit rise in NT-proBNP was associated with a 41% increase in risk (HR: 1.41, 95% CI: 1.20–1.66, p<0.0001). A one-unit (1%) reduction in LVEF correlated with a 10% increase in heart failure risk (HR: -0.90, 95% CI: 0.87–0.93, p<0.0001). Conclusion(s) Genetic status is a predictor of heart failure outcomes independent of LVEF and NT-proBNP levels in HCM. This underscores the importance of genetic testing in the clinical management of HCM.