Transapical approach to myectomy for midventricular obstruction in hypertrophic cardiomyopathy

Midventricular obstruction in hypertrophic cardiomyopathy (HCM) is less common than subaortic obstruction, and there are few data on outcomes after surgical treatment.

We reviewed 56 consecutive patients (28 men) with HCM and midventricular obstruction who underwent myectomy between February 1997 and June 2012. Five patients had prior myectomy for subaortic obstruction. Mean age was 42 ± 17 years. Preoperatively, 51% of patients had dyspnea, and the remaining had palpitations (25%), angina (5%), or syncope (9%).

Midventricular obstruction was relieved by means of a transaortic myectomy in 5 patients, a transapical approach in 32 patients, and combined transaortic and transapical incisions in 19 patients. In 13 patients, an apical aneurysm or pouch was repaired at the time of midventricular myectomy. There were no early deaths. Intraoperative intraventricular gradients were reduced from 64 ± 32 mm Hg before myectomy to 6 ± 12 mm Hg postoperatively (p ≤ 0.0001). Early complications included atrial arrhythmias in 5 patients and reoperation for bleeding in 4 patients. Fifty patients had follow-up beyond 30 days (median, 1.6 years; range, 33 days to 13 years). Survival at 1 and 5 years was 100% and 95%, and average New York Heart Association class improved from 2.9 ± 0.7 preoperatively to 1.3 ± 0.6 postoperatively (p = 0.0001). There were no aneurysms related to the apical incision; 2 patients had late reoperation, 1 for resection of right atrial mass to prevent embolus.

A transapical approach allows excellent exposure for midventricular myectomy and relief of intraventricular gradients and related symptoms. There were no complications unique to the apical incision, and 5-year survival was similar to expected survival (95% versus 97%).