Prediction of Sarcomere Mutations in Subclinical Hypertrophic Cardiomyopathy: Captur et al: Subclinical Phenotype in HCM

Hypertrophic cardiomyopathy (HCM) is a common hereditable heart disease with a population prevalence of 1 in 500 and affected individuals are at risk of adverse outcomes, including sudden cardiac death1 and progression to heart failure. HCM is frequently caused by dominant mutations in sarcomere protein genes; present in 30-60 % of patients.2 Due to the growing availability of advanced imaging, myocardial architectural abnormalities can be investigated in subclinical HCM sarcomere gene mutation carriers before the development of left ventricular hypertrophy (genotype-positive, LVH-negative: G+LVH−). Initially reported separately and in single-center studies, some of the cardiac abnormalities of subclinical HCM (myocardial crypts,3 anterior mitral valve leaflet [AMVL] elongation,4 abnormal LV apical trabeculae5 and smaller LV systolic cavity6) have recently been shown to cluster into an identifiable phenotype by cardiovascular magnetic resonance (CMR)5 with emerging data suggesting that crypts may be an important morphological feature in genetic HCM.3,7 Here we present a multi-center study exploring crypts and other morphological features in subclinical HCM to identify the parameters that are most strongly indicative of the presence of a sarcomere gene mutation before the development of LVH.