Hypertrophic cardiomyopathy with moderate septal thickness and mitral regurgitation: long-term surgical results
Elisabetta Lapenna, Teodora Nisi, Davide Carino, Marta Bargagna, Stefania Ruggeri, Edoardo Zancanaro, Benedetto Del Forno, Davide Schiavi, Eustachio Agricola, Alessandro Castiglioni, Ottavio Alfieri, Michele De Bonis
Abstract
OBJECTIVES: The aim of this study was to assess the long-term outcomes of different surgical strategies in patients with hypertrophic obstructive cardiomyopathy (HOCM) with septal thickness ≤18 mm and systolic anterior motion (SAM)-related moderate-to-severe mitral regurgitation (MR). METHODS: Seventy-six HOCM patients with septal thickness 17 [16; 18] mm, resting left ventricle outflow tract gradient 60 [41; 85] mmHg and SAM-related MR ≥2+/4+, underwent septal myectomy alone (54%) or mitral valve (MV) surgery ± myectomy (46%). RESULTS: No hospital death and no ventricular septal defect occurred. Patients undergoing MV surgery ± myectomy had longer cardiopulmonary bypass and X-clamp times (77 [60-106] vs 51 [44-62] min, P < 0.001 and 56 [45-77] vs 32 [28-41] min, P < 0.001) and higher incidence of low output syndrome (11% vs 0%, P = 0.04). Follow-up was 98.6% complete, median 8 years [3-11]. There were no statistically significant differences in overall survival (P = 0.069) with survival rates at 9 years of 96 ± 4% in the myectomy alone group and 81 ± 8% in the MV surgery ± myectomy one. At 9 years, cumulative incidence function of cardiac death was 12 ± 6% in the MV surgery ± myectomy group vs 0% in the myectomy one, P = 0.06. Multivariable analysis identified age and previous septal alcoholization as predictors of cardiac death (hazard ratio (HR) = 1.1, 95% confidence interval (CI) 1.0-1.1, P = 0.004 and HR = 2.9, 95% CI 1.0-8.3, P = 0.042). The 9-year cumulative incidence function of recurrence of MR ≥2+, with death as competing risk, was 3 ± 2.8% in the MV surgery ± myectomy group vs 25 ± 6.9% in the myectomy one, P = 0.005. CONCLUSIONS: In HOCM patients with moderate septal thickness and SAM-related MR, as the degree of septal hypertrophy decreases, addressing the abnormalities of the MV apparatus may become necessary to provide a durable resolution of left ventricle outflow tract obstruction and SAM-related MR. However, performing myectomy alone, whenever possible, seems to be associated to a better postoperative course and a trend towards lower cardiac mortality at follow-up, despite a higher rate of residual moderate MR.