[Recovery of left ventricular function after mitral valve replacement for chronic mitral regurgitation: optimal timing of operation according to long-term recovery].
OBJECTIVE
Surgical outcome for mitral regurgitation has significantly improved in recent years, so consideration of the optimal operative timing to achieve long-term quality of life for the patients has become more important. Preoperative indices that predict postoperative left ventricular function are very important for decision of the operative timing. To reassess the optimal operative timing for mitral regurgitation, long-term recovery of the postoperative left ventricular function was correlated with preoperative left ventricular end-systolic volume index(LVESVI).


METHODS
One hundred eighty-two patients with mitral regurgitation underwent standard mitral valve replacement between January 1973 and June 1993. The patients were divided into 3 groups according to the preoperative LVESVI: Group I (LVESVI > or = 100 ml/m2) included 23 patients, Group II (60 < or = LVESVI < 100 ml/m2) 81 patients and Group III (LVESVI < 60 ml/m2) 78 patients. Two-dimensional echocardiography was performed to measure left ventricular diastolic dimension, systolic dimension, fractional shortening, end-systolic wall stress and mass index before operation(pre), and 1 month(early) and 3 years(late) after the operation.


RESULTS
Left ventricular diastolic dimension in each group decreased in the early period, but Group I returned to the abnormal range in the late period. Left ventricular systolic dimension in Groups I and II was at the upper limit of the normal range in the early period and returned to the abnormal range in the late period, but Group III remained within the normal range throughout the study. Fractional shortening in all groups decreased to the abnormal range in the early period, but only Group III returned to the normal range in the late period. End-systolic wall stress in Group I tended to increase, but Group II had no change, and Group III returned to the normal range during the early and late periods. Mass index in Groups I and II remained within the abnormal range, but Group III returned to the normal range in the late period.


CONCLUSIONS
Long-term recovery of the left ventricular function in Group I showed a continuous deterioration due to irreversible change of the left ventricular myocardium and Group II showed no significant change. In contrast, Group III demonstrated a significant improvement after standard mitral valve replacement. Patients with preoperative LVESVI of more than 100 ml/m2 have already lost the optimal timing for surgical treatment of mitral regurgitation.
Ishitoya
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Department of Cardiovascular Surgery, Tokyo Women's Medical University.
D002908:Chronic Disease; D004452:Echocardiography; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery; D008944:Mitral Valve Insufficiency / Q000503:physiopathology / Q000534:rehabilitation / Q000601:surgery*; D011788:Quality of Life; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology*