LONG-TERM CLINICAL AND ECHOCARDIOGRAPHIC FOLLOW-UP AFTER SURGICAL-CORRECTION OF HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY WITH EXTENDED MYECTOMY AND RECONSTRUCTION OF THE SUBVALVULAR MITRAL APPARATUS

Background The standard surgical approach to hypertrophic obstructive cardiomyopathy (HOCM) was modified in the present series with a combin ation of extended myectomy with partial excision and mobilization of t he papillary muscles. Methods and Results Between 1979 and 1992, 58 pa tients (38 men and 20 women; mean age; 49+/-24 years) with HOCM were o perated on with the use of this different technique. Their intraventri cular gradients were 79+/-33 (+/-SD) mm Hg at rest and increased to 14 7+/-48 mm Hg with provocative maneuvers. Mild-to-moderate mitral regur gitation was present in 60% of the patients, and severe regurgitation was present in 5%. Ten patients required additional aortocoronary bypa ss graft surgery. Follow-up (mean, 84 months) was complete (100%). Hem odynamic improvement was documented by a significant (P<.01) decrease in left ventricular end-diastolic pressure from 19+/-9 to 14+/-6 mm Hg and reduction of basal outflow tract gradients to 5+/-7 nlm Hg at res t and 16+/-24 mm Hg after provocation. Late mortality was 1.4% per pat ient-year, and no sudden cardiac deaths occurred during follow-up, Fun ctional status was excellent for 84% of the patients; 8 patients were in New York Heart Association functional class III, and none were in c lass IV. Echocardiography revealed no outflow tract obstruction.Conclu sions Extended myectomy and reconstruction of the subvalvular mitral a pparatus in HOCM result in excellent functional improvement with relie f of outflow tract obstruction. The technique can be performed safely despite its more aggressive surgical nature and allows an individualiz ed strategy depending on the patient's extent and distribution of left ventricular hypertrophy.