Aortic regurgitation is common in hypertrophic cardiomyopathy: An echocardiography and cardiovascular magnetic resonance study

•Aortic regurgitation is a common comorbidity of HCM.•Aortic regurgitation is more common in HCM patients with LVOTO.•LVOTO and age were independent risk factors of AR in HCM patients. To investigate the incidence, mechanism, and risk factors of aortic regurgitation (AR) in patients with hypertrophic cardiomyopathy (HCM) by using echocardiography and cardiac magnetic resonance (CMR). 105 HCM patients, 52 hypertension (HTN) patients and 50 healthy controls (HC) were retrospectively recruited. HCM patients were divided into 38 with AR (HCMAR) subject and 67 without AR. The subaortic complex, D1 (the largest distance of the interventricular septum that protruded into the LVOT) and D3 (the LVOT effective width) were assessed and compared between the two groups of HCM patients. AR was more common in HCM than in HTN and HC (36 %, 17 %, and 10 %, respectively, P = 0.001). HCM patients with AR were older (58 ± 11 vs. 45 ± 16 years, P < 0.001) and had a higher incidence of hypertension (55 % vs. 33 %, P = 0.03). D1 was greater (13.5 ± 4.4 vs. 10.6 ± 4.0 mm, P = 0.001), and D3 was shorter in the HCMAR group (10.2 ± 5.3 vs. 13.7 ± 5.9 mm, P = 0.003). Anterior mitral leaflet length and left atrial diameter were greater in HCMAR group (all P < 0.05). On multivariable logistic regression analysis, the independent risk factors of AR in HCM patients were LVOTO and age. This study demonstrated that AR is a common comorbidity of HCM, especially in patients with LVOTO. LVOTO and age were independent risk factors of AR in HCM patient.