Surgical management of left ventricular outflow tract obstruction in a specialized hypertrophic obstructive cardiomyopathy center

Abstract

Objectives: This study evaluates operative approach and contemporary surgical outcomes in the management of left ventricular outflow tract obstruction by a single surgeon at a high-volume, specialized hypertrophic cardiomyopathy center.

Methods: This is a retrospective review of 1559 consecutive operations for left ventricular outflow tract obstruction from 2005 to 2015. Demographic profiles, echocardiogram-derived ventricular morphology and hemodynamics, operative data, and in-hospital outcomes were analyzed.

Results: Of the 1559 operations, 586 were isolated septal myectomies, 522 were myectomies with mitral valve or subvalvular apparatus intervention, 422 were myectomies with another concomitant procedure, and 29 were isolated mitral valve interventions without myectomy. Common mitral valve interventions included anterior leaflet shortening (16%), chordae tendineae resection (9.8%), papillary muscle resection (7.2%), and papillary muscle reorientation (7.5%). Ninety-two patients underwent mitral valve replacement, 42 for left ventricular outflow tract obstruction and 50 for intrinsic mitral valve pathology. Patients undergoing mitral interventions had thinner septums (18 ± 0.4 mm vs 22 ± 0.5 mm, P < .001) and less myocardium removed (6.2 ± 3.5 g vs 8.8 ± 3.8 g, P < .001) than patients without a mitral intervention. Prevalence of in-hospital permanent pacemaker insertion was 4.2% (n = 1334) for complete heart block and 1.1% (n = 464) for isolated septal myectomy with normal preoperative conduction. Overall, there were 2 postoperative ventricular septal defects (0.13%) and none for isolated myectomies. Operative mortality was 0.38%.

Conclusions: Septal myectomy can be performed safely with excellent outcomes when the procedure is performed by a highly experienced surgeon in a high-volume, specialized center. A mitral valve intervention is a useful adjunct in patients with moderate hypertrophy.

Keywords: hypertrophic obstructive cardiomyopathy; mitral valve pathology; mitral valve repair; septal myectomy; transesophageal echocardiography.