Short and Medium Term Outcomes of Surgery for Patients With Hypertrophic Obstructive Cardiomyopathy

BACKGROUND: We report one surgeon's experience of corrective surgery for hypertrophic obstructive cardiomyopathy (HOCM) over a 10-year span and comment on factors that influence longer term outcomes. Septal myectomy (SM) and adjunctive procedures, including shortening of the aorta, a novel technique in HOCM patients, are described. METHODS: Perioperative data were obtained by retrospective review of institutional surgical databases between 2001 and 2011. Review of most recent echocardiogram and clinical status by telephone interview was performed. RESULTS: A total of 211 patients underwent SM for HOCM. There was a bimodal age distribution related to sex; mean age for males and females was 46 ± 13 and 54 ± 14 years, respectively (p < 0.001). Functional New York Heart Association (NYHA) class improved significantly after surgery; 79% were in class III-IV preoperatively and 84% were in class I-II at follow-up (p < 0.001). Sixty percent had angina of Canadian Cardiovascular Society (CCS) grade III-IV preoperatively and 89% were in CCS I-II at follow-up (p < 0.001). There were significant improvements in resting left ventricular outflow tract gradient (64 ± 36 to 5 ± 5 mm Hg, p < 0.001), right ventricular systolic pressure (36 ± 7.3 to 32 ± 8 mm Hg, p < 0.001), left atrial size (4.6 ± 0.7 to 4.3 ± 0.6 cm, p < 0.001), and grade of mitral regurgitation (moderate to severe mitral regurgitation 28% to 3.5%, p < 0.001). In-hospital mortality was 0.5%, 1 year survival 98.6%, and 5-year survival 98.1%. Predictors of worse clinical outcomes were preoperative NYHA and CCS class III-IV (p < 0.001, p = 0.05), new onset atrial fibrillation (p < 0.001), and female sex (p = 0.03). CONCLUSIONS: Septal myectomy in patients with obstructive HOCM offers excellent symptom relief and minimal operative risk.