Mid-Term Outcome of Mitral Valve Replacement During Septal Myectomy for Hypertrophic Obstructive Cardiomyopathy

Background The mitral valve shows significant involvement in hypertrophic obstructive cardiomyopathy (HOCM). The mid-term outcomes of management of HOCM by prosthetic valve replacement with septal myectomy remain unclear. This study compared the prognosis of patients with and without prosthetic valve replacement. Methods From 01/2009 until 10/2015, 24 patients with HOCM underwent septal myectomy with or without valve repair/replacement were recruited. A total of 23 patients underwent echocardiographic evaluation before and after the operation. The follow-up duration ranged from 0.4 to 7 years (median 2.5 years). The Kaplan-Meier test was used to explore the association between prosthetic valve replacement and overall/disease-free survival among HOCM patients. Results A total of 9 patients underwent septal myectomy with/without mitral valve repair (MVr), and the other 15 patients underwent septal myectomy with mitral valve replacement (MVR). Six patients treated with MVR had unfavorable outcomes, including one peri-operative and three late deaths; one patient suffered from aborted sudden death, and one patient was treated for prosthetic valve endocarditis. Prosthetic valve replacement was associated with poor disease-free survival (p = 0.025). Conclusions Septal myectomy with or without-MVr was associated with a better outcome than septal myectomy with MVR in HOCM patients. The differences in prognosis were caused by more complicated left ventricular outflow tract structures and more prosthetic valve complications among patients undergoing MVR.