RESUMO
PURPOSE: to assess effectiveness and safety of extended myectomy performed in patients with hypertrophic obstructive cardiomyopathy (HOCM) with midventricular obstruction. MATERIAL AND METHODS: Between 2010 and 2013 185 HOCM patients were operated for left ventricular outflow tract (LVOT) obstruction. Among these patients 32 had midventricular obstruction. Their age was 22-74 (mean 51.9+/-14.2) years. Mean peak gradient across LVOT was 89.1+/-20.4 mm Hg, thickness of interventricular septum was 26.9+/-4.3 mm. Operations were guided by intraoperative transesophageal echocardiography (TEE). RESULTS: There were no early deaths. Gradient at LVOT according to TEE decreased to 15.4+/-5.7 mm Hg. There were no complications specific for extended myectomy (such as ventricular septal defect, left ventricular wall rupture, or aortic regurgitation). In 2 (6.9%) patients permanent pacemaker was implanted because of complete atrio-ventricular block. Mean follow-up was 18.7 (95% confidence interval [CI] 17.2 to 20.3) months. Kaplan-Meier estimate of survival was 100% at 12 and 94.2% (95% CI 65.8-99.1%) at 22 months. CONCLUSION: Extended myectomy can be safely and effectively performed in HOCM patients with midventricular obstruction and should be considered individually in each patient.