PROGNOSTIC VALUE OF LEFT-VENTRICULAR EJECTION FRACTION RESPONSE TO EXERCISE DURING LONG-TERM FOLLOW-UP AFTER CORONARY-ARTERY BYPASS GRAFT-SURGERY

Background. Recent data, albeit based on operations often performed mo re than 15 years ago, suggest that survival benefits of coronary arter y bypass graft surgery (CABG) generally are lost within 10 years after operation. A reliable noninvasive method for periodic assessment of i schemia severity after operation might permit optimal timing of additi onal therapy to minimize loss of benefits. Methods and Results. To det ermine the impact of left ventricular ejection fraction (LVEF) during exercise on prognosis in patients who have undergone CABG, results of rest and exercise radionuclide cineangiography were correlated with mo rtality, major nonsurgical cardiac events, and cardiac event-free or s urgery-free survival in 192 patients who underwent index radionuclide study greater-than-or-equal-to 1 month (average, 26 months) after CABG . Average follow-up after study was 8.7 years among event-free patient s. Initial events during follow-up included 31 deaths, 19 nonfatal myo cardial infarctions, and 33 late repeat CABG or angioplasties (PTCA). Stepwise Cox regression analysis identified change (DELTA) in LVEF wit h exercise as the strongest independent predictor of cardiac death, ma jor nonsurgical cardiac events, and cardiac event-free or surgery-free survival (P<.0001, all outcomes). Change in heart rate with exercise, completeness of revascularization, and New York Heart Association fun ctional class for angina provided additional independent information. With each 10% decrement in DELTALVEF, the hazard of cardiac death incr eased more than twofold, and the hazard of major nonsurgical cardiac e vents considered alone or in combination with repeat CABG or PTCA incr eased >1.5 times. ConclusIons. Thus, assessment of DELTALVEF is progno stically useful after CABG. Assessment of this variable may help deter mine the need for repeat CABG. The utility of this approach now should be confirmed by longitudinal prognostic study.