Prognostication in 3-vessel coronary artery disease based on left ventricular ejection fraction during exercise - Influence of coronary artery bypassgrafting

Background-Previous data indicate that left ventricular ejection fraction ( LVEF) provides prognostic information among patients with coronary artery d isease (CAD), but the value of such testing specifically for defining benef its of coronary artery bypass grafting (CABG) may relate to severity of exe rcise-inducible ischemia measured noninvasively before surgery. Methods and Results-To determine the independent prognostic importance of p reoperative ischemia severity for predicting outcomes of CABG among patient s with extensive CAD, we monitored 167 stable patients with angiographicall y documented 3-vessel CAD (average follow-up of 9 years in event-free patie nts) who previously had undergone rest and exercise radionuclide cineangiog raphy. Their course was correlated with data obtained during initial radion uclide testing, coronary arteriography, and clinical evaluation at study en try, Fifty-two patients received medical treatment only, and 115 underwent CABG (44 early [less than or equal to 1 month after initial study]). Multiv ariate Cox model analysis indicated that change (a) in LVEF from rest to ex ercise during radionuclide study was the strongest independent predictor of major cardiac events (P=0.003) before surgery and also predicted magnitude of CABG benefit (P=0.04). Patients with Delta LVEF -8% or less derived sig nificant survival-prolonging and event-reducing benefit from CABG performed less than or equal to 1 month after initial testing (P<0.02 for cardiac de ath and P=0.008 for cardiac events], early CABG versus medical-treatment-on ly patients); similar benefits were absent among patients with Delta LVEF m ore than -8%, and among those in whom CABG was deferred. Conclusions-Assessment of ischemia severity based on LVEF response to exerc ise enables effective prognostication among patients with 3-vessel CAD and defines the likelihood of life-prolonging and event-reducing benefits from CABG.