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.