Influence of left ventricular function on survival 3 to 4 years after aortocoronary bypass.

Preoperative left ventricular ejection fraction (EF) was calculated using single plane cineventriculography in 93 patients in whom aortocoronary bypass surgery was performed before July 1970. Preoperative EF (mean plus or minus SEM) was 0.29 plus or minus 0.04 in 9 patients deceased between 2 and 35 mth after operation, significantly lower (p less than 0.001) than EF of 84 patients having survived 3 yr or more (0.55 plus or minus 0.02). The 3- to 4-yr mortality in these patients was 22.2% when preoperative EF was less than 0.50 and 1.75% when it was greater than or equal to 0.50 (p less than 0.01). Likewise, late mortality rose to 43.7% when EF was less than 0.40, compared to 2.6% when it was greater than or equal to 0.40 (p less than 0.005). In 21 patients in this series, left ventricular volumes and EF showed no significant difference before, approximately one year and between 3 and 4 yr after operation. This included 9 patients with normal or near normal contraction and 12 patients with impaired ventricular contraction preoperatively. Thus, in this study, preoperative EF was a major determinant of long-term prognosis after aortocoronary bypass and EF was not improved between 3 and 4 yr postoperatively. These data suggest, then, that in order to enhance survival after aortocoronary bypass, patients should be operated on before significant myocardial damage has occurred.