ABSTRACT
Objectives:To analyze the impact of extended myectomy on reducing mitral regurgitation in patients with hypertrophic obstructive cardiomyopathy (HOCM). Methods:We retrospectively analyzed 480 consecutive HOCM patients who underwent surgical treatment by the same surgeon in our institution from October 2002 to July 2017. The efficacy of extended myectomy for reducing mitral regurgitation and left ventricular outflow tract (LVOT) obstruction were evaluated by echocardiography after surgery. Results:Among the 480 patients, 22 (4.6%) received concomitant mitral repair or replacement because of their intrinsic mitral diseases. In the remaining 458 (95.4%) patients without concomitant mitral valve surgery, 1 (0.2%) died at the 5th day after surgery because of infective shock, and another 4 (0.9%) lost to follow-up, a total of 453 (98.9%) patients underwent echocardiographic follow-up (median follow-up time:6 months [3, 12]). During follow-up, left ventricular out flow tract gradient was significantly decreased from (89.1±30.6) to (12.8±11.6) mmHg (P＜0.001); the number of patients with systolic anterior motion (SAM) of mitral leaflets decreased from 451(98.5%) to 42 (9.3%) (P＜0.001); 297 (64.8%) patients presented with moderate or severe mitral regurgitation before surgery, which decreased to 14 (3.1%) at follow-up (P＜0.001); the multivariate regression analysis showed that patients with residual SAM were significantly associated with a higher incidence of moderate to severe mitral regurgitation during follow-up (odds ratio 30.334, 95% confidence interval:5.619-163.739, P＜0.001). Conclusions:Extended myectomy, combined with dividing the anomalous links between mitral apparatus and septum, and trimming papillary muscles, yields satisfactory outcomes of relieving LVOT obstruction and reducing mitral regurgitation in most of patients with HOCM. Concomitant mitral valve surgery is rarely required unless the patient have intrinsic mitral valve disease.