Prognostic significance of endocardial viability ratio in aortocoronary bypass surgery.

: Although aortocoronary bypass (ACB) for patients with stable angina carries a low mortality, some unexpected deaths do occur. Since in patients with normal coronary arteries the endocardial viability ratio (EVR) can be correlated with subendocardial perfusion, with a ratio of 0.7 or less indicating ischemia of the left ventricular subendocardium, and since the EVR postoperatively is useful in determining the need for intra-aortic balloon pump assist (IABPA), it was decided to ascertain whether the EVR might have prognostic value in patients with stable angina scheduled for standard ACB. Three groups of patients were studied: 50 with stable angina, 24 who had died after ACB, and 18 who required IABPA for cardiogenic shock after surgery for stable angina. No significant differences were found for cardiac index, left ventricular end-diastolic pressure, left ventricular ejection fraction and pre- and postoperative artery scores, but there were significant differences in the EVR between the first and second groups and between the first and third groups (P less than 0.01 in each instance). These findings suggest that the left ventricular EVR may indeed be of prognostic value in patients scheduled to undergo ACB and that use of IABPA, which produces an increase in EVR, may be useful in patients with EVRs of less than 0.7, even if other parameters of cardiac function are normal.