Comparing echocardiographic characteristics in genotype positive-phenotype positive hypertrophic cardiomyopathy and hypertensive left ventricular hypertrophy

Abstract

Aims: There is little information about hypertrophic cardiomyopathy (HCM) with pathologic genetic mutations and concurrent hypertension (HTN). Hypertensive left ventricular hypertrophy (LVH) does not exclude an underlying genetic aetiology. Methods and results: This was a single-centre case-control study of 39 adults with pathologic HCM mutations, confirmed by genetic testing, compared to 39 age-and gender-matched patients with hypertensive LVH. The gene-positive HCM cohort was further stratified by the coexisting presence or absence of HTN. Clinical and echocardiographic characteristics were compared. Of 39 gene-positive HCM, 43.6% (17/39) had concurrent HTN. The gene-positive HCM cohort had larger left atrial (LA) area (22.1 cm2 vs. 18.9 cm2, P = 0.002), more diastolic predominant pulmonary vein flow (38.5% vs. 7.7%, P = 0.001), and more moderate diastolic dysfunction (33.3% vs. 12.8%, P = 0.032) when compared with the hypertensive LVH cohort. Greater left ventricular (LV) mass (277.7 g vs. 207.7 g, P = 0.025), increased frequency of severe LVH (58.8% vs. 27.3%, P = 0.047), and more abnormal global longitudinal strain (GLS) (-14.1% vs.-16.9%, P = 0.049) was observed in the gene-positive HCM cohort with concurrent HTN. Conclusion: Gene-positive HCM, compared to hypertensive LVH, is characterized by more advanced diastolic dysfunction and larger LA size. Gene-positive HCM patients with concomitant HTN had greater LV mass, more severe LVH, and more abnormal GLS, suggesting HTN may negatively affect the progression of myocardial dysfunction in genetic HCM. LVH out-of-proportion to pressure burden in HTN patients should raise suspicion of underlying genetic HCM.