Sustained improvement after combined anterior mitral leaflet extension and myectomy in hypertrophic obstructive cardiomyopathy

Background - Mitral leaflet extension (MLE) combined with septal myectomy is a new surgical approach to treat hypertrophic obstructive cardiomyopathy (HOCM) and an enlarged mitral leaflet area. The study presents the long-term clinical results and outcome of this technique. Methods and Results - MLE entails grafting a glutaraldehyde-preserved autologous pericardial patch onto the center portion of the anterior mitral valve leaflet. Twenty-nine patients with HOCM were studied. Mean follow-up (+/-SD) was 3.4 +/- 2.1 years (range 3 months to 7.7 years). The preoperative calculated mitral leaflet area was 16.7 +/- 3.4 cm(2). New York Heart Association functional class improved significantly from 2.8 +/- 0.4 to 1.3 +/- 0.4 (P < 0.05), width of the interventricular septum decreased from 23 ± 4 to 17 ± 2 mm (P < 0.05), left ventricular outflow tract gradient decreased from 100 +/- 20 to 17 +/- 14 mm Hg (P < 0.01), severity of mitral regurgitation graded on a scale from 0 to 4+ decreased from 2.5 ± 0.9 to 0.5 ± 0.6 (P < 0.01), and severity of the systolic anterior motion of the mitral valve graded on a scale from 0 to 3+ decreased from 2.9 +/- 0.3 to 0.5 +/- 0.7 (P < 0.01) postoperatively. There were no deaths associated with surgery. Conclusions - Long-term follow-up shows sustained improvement in functional status, reduction of outflow tract obstruction, and attenuation of mitral regurgitation and systolic anterior motion of the mitral valve. In this respect, the new technique widens the surgical applications in HOCM.