Excision of anomalous muscle bundles as an important addition to extended septal myectomy for treatment of left ventricular outflow tract obstruction.

Objective: This study aims to report our preliminary experience and anatomic findings in the surgical treatment and postoperative management of hypertrophic obstructive cardiomyopathy.

Methods: This study included 277 patients with hypertrophic obstructive cardiomyopathy (168 [60.65%] were male), with a median age of 47 years (interquartile range, 35-54 years), who underwent surgical myectomy performed by 1 surgeon in Fuwai Hospital between May 2010 and April 2015. The median follow-up was 14 months (interquartile range, 7-24 months).

Results: A total of 127 patients (45.85%) underwent concomitant procedures, and 2 patients (0.72%) died in the early perioperative days. The left ventricular outflow gradient decreased from 78 mm Hg (interquartile range, 61-100 mm Hg) to 11 mm Hg (interquartile range, 8-15 mm Hg) when discharged (P < .001). Of the 228 patients with well-documented anatomic description, more than 80% had various intraventricular anomalies. The cumulative survival was 99.28% (95% confidence interval, 97.15-99.82) at 1 year and 96.98% (95% confidence interval, 92.56-98.79) at 5 years. Of the surviving 272 patients, 268 (98.53%) were categorized with functional class I and II of the New York Heart Association classification at the latest evaluation.

Conclusions: Anomalous muscle bundles are common in hypertrophic obstructive cardiomyopathy, and they may lead to middle-apical obstruction. Surgical myectomy provides excellent clinical outcomes with low risk for sufficient relief of obstruction and radical correction of intraventricular anomalies in patients with hypertrophic obstructive cardiomyopathy.