Initial results of combined anterior mitral leaflet plication and ventricular septal myotomy-myectomy for relief of left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy.

BACKGROUND: Several operations (most commonly ventricular septal myotomy-myectomy and also mitral valve replacement) have been performed to relieve symptoms and obstruction to left ventricular outflow in patients with hypertrophic cardiomyopathy (HCM).

METHODS AND RESULTS: In an effort to establish an alternative to mitral valve replacement, combined septal myotomy-myectomy and suture plication of the anterior mitral valve leaflet was performed in a subgroup of 36 severely symptomatic patients with obstructive HCM. These patients were selected primarily because the mitral leaflets were judged morphologically at the time of operation to be of sufficient size relative to that of the outflow tract to represent a risk for residual systolic septal contact and outflow obstruction. The effects of operation were assessed in 34 patients; of the 33 with preoperative symptoms, 28 (85%) reported substantial functional improvement after surgery over an average follow-up of 2.2 years. Of 29 patients with complete hemodynamic data, basal outflow gradient was obliterated or reduced substantially by surgery (to < or = 35 mm Hg) in 26 patients (90%) and for the group from 81 +/- 42 to 16 +/- 24 mm Hg (p < 0.001); provocable gradient with isoproterenol infusion also decreased considerably (from 109 +/- 50 to 47 +/- 25 mm Hg; p < 0.001). Echocardiographic studies showed that plication limited the systolic anterior motion of anterior mitral leaflet. There was no hemodynamic evidence of mitral stenosis, and in only one patient did mitral regurgitation increase after surgery.

CONCLUSIONS: Mitral valve plication combined with myotomy-myectomy in obstructive HCM 1) can be performed safely and does not adversely alter mitral valve function, 2) relieves symptoms and outflow obstruction under basal and provocable conditions, and 3) may represent an alternative to mitral valve replacement in selected patients with elongated and enlarged mitral leaflets.