A new mitral valve repair strategy for hypertrophic obstructive cardiomyopathy

Previously, surgery hypertrophic obstructive cardiomyopathy (HOCM) has consisted primarily of septal myectomy and/or resection of the anterior mitral leaflet with low-profile valve replacement. However, recent studies have shown that the anterior papillary muscle and chordal fan can contribute to obstruction, and also that significant mitral regurgitation (MR) may be encountered. Hence, a surgical procedure was devised to address all components of this disorder.

A 37-year-old man had a history of heart murmur and NYHA class IV symptoms, despite beta-blocker therapy. Echocardiography showed severe septal hypertrophy, systolic anterior motion (SAM) of the mitral valve, severe MR and a 185 mmHg resting outflow tract gradient. At surgery, the anterior papillary muscle was found to be medially displaced and contributing to outflow obstruction. The anterior papillary muscle and chordae were resected, a 'traditional' septal myectomy was performed, and a full annuloplasty ring placed. The mitral valve was repaired by connecting the left aspect of the leaflets to the posterior papillary muscles, using Gore-Tex artificial chords.

The patient recovered uneventfully. Interval echocardiography at one year showed a negligible outflow gradient, relief of SAM and mild residual MR. The patient currently is active, essentially asymptomatic, and not receiving any medical therapy.

Previous approaches to HOCM have been limited by a small incidence of recurrent outflow gradients, pacemaker requirement, persistent MR or complications of the prosthetic valves. By comprehensively addressing all components of outflow obstruction and mitral dysfunction, this combined procedure may produce better results in certain subsets of HOCM, with the excellent late prognosis of artificial chordal replacement.