Value of Genetic Testing for the Prediction of Long-Term Outcome in Patients With Hypertrophic Cardiomyopathy

Pathogenic gene mutations are found in about 50% of patients with hypertrophic cardiomyopathy (HC). Previous studies have shown an association between sarcomere mutations and medium-term outcome. The association with long-term outcome has not been described. The aim of this cohort study was to assess the long-term outcomes of patients with genotype positive (G+) and genotype negative (G) HC. The study population consisted of 626 patients with HC (512 probands and 114 relatives) who underwent phenotyping and genetic testing from 1985 to 2014. End points were all-cause mortality, cardiovascular (CV) mortality, heart failure (HF) related mortality, and sudden cardiac death/aborted sudden cardiac death (SCD/aborted SCD). Kaplan Meier and multivariate Cox regression analyses were performed. A pathogenic mutation was detected in 327 patients (52%). G+ probands were younger than G probands (46 +/- 15 vs 55 +/- 15. years, p <0.001), had more non sustained ventricular tachycardia (34% vs 13%; p <0.001), more often a history of syncope (14% vs 7%; p = 0.016), and more extreme hypertrophy (maximal wall thickness >= 30 mm, 7% vs 1%; p <0.001). G probands were more symptomatic (New York Heart Association >= II, 73% vs 53%, p <0.001) and had higher left ventricular outflow tract gradients (42 +/- 39 vs 29 +/- 33 mm Hg, p = 0.001). During 12 +/- 9 years of follow-up, G+ status was an independent risk factor for all-cause mortality (hazard ratio [HR] 1.90, 95% CI 1.14 to 3.15; p = 0.014), CV mortality (HR 2.82, 95% CI 1.49 to 5.36; p = 0.002), HF-related mortality (HR 6.33, 95% CI 1.79 to 22.41; p = 0.004), and SCD/aborted SCD (HR 2.88, 95% CI 1.23 to 6.71; p = 0.015). In conclusion, during long-term follow-up, patients with G+ HC are at increased risk of all-cause death, CV death, HF-related death, and SCD/aborted SCD. (C) 2016 Elsevier Inc. All rights reserved.