Superiority of mitral valve repair in surgery for degenerative mitral regurgitation

OBJECTIVES: We aimed to assess the influence of type of operation on outcomein degenerative mitral regurgitation. METHODS: We compared outcomes in 278 consecutive patients who underwentmitral valve repair (167 patients), replacement with subvalvularpreservation (22 patients) and without subvalvular preservation(89 patients) for degenerative mitral regurgitation. RESULTS: There was a trend towards lower mortality with repair and replacementwith subvalvular preservation compared to replacement withoutsubvalvular preservation. Thirty-day mortality was 1·2%vs 0·0% vs 4·7% (ns) respectively. Six-year survivalwas, respectively, 67·8±7·4% (P=0·088)vs 80·8±11·0% (P=0·25 vs 63·3±5·9%for all-cause death, 78·5±6·8% (P=0·063)vs 95·5±4·4% (P=0·092) vs 67·6±5·9%for all complication-related death and 80·5±6·9%(P=0·076) vs 100·0±0·0% (P=0·045)vs 72· ± 5·8% for complication-relateddeath due to myocardial failure. Multivariate analysis confirmedindependent beneficial effects from repair compared to replacementwithout subvalvular preservation on complication-related death(hazard ratio 0·42, P=0·010) and death from myocardialfailure (hazard ratio 0·40 P=0·014), and fromrepair compared to mechanical replacement on thromboembolism(hazard ratio 0·45, P=0·029) and anticoagulation-relatedhaemorrhage (hazard ratio 0·19, P=0·026). CONCLUSIONS: Mitral valve repair is superior to replacement. The greatestsurvival advantage is in reduced mortality from myocardial failure.Repair should be the operation of choice for degenerative mitralregurgitation.