Anterior Wall Viability and Low Ejection Fraction Predict Functional Improvement After CABG1

BackgroundAbsence of myocardial hyperenhancement on cardiac magnetic resonance imaging (CMR) predicts functional improvement after coronary artery bypass graft surgery (CABG). However, not all patients with absence of hyperenhancement improve their left ventricular ejection fraction (LVEF) after CABG. We sought to identify other characteristics associated with improvement in LVEF after CABG.MethodsPreoperative CMR was obtained in 95 patients who underwent CABG from 2003 to 2007 at The Ohio State University Medical Center. Follow-up LVEF was assessed by echocardiogram between 3 wk and 2 y postoperatively (mean: 7 ± 0.5 mo). Improvement in LVEF was defined as a postoperative increase in LVEF ≥ 10%. CMR and clinical factors were analyzed for predictors of functional improvement.ResultsMean age was 61 ± 1 y with 79 males. LVEF improved from 28% ± 2% preoperatively, to 38% ± 2% postoperatively (P < 0.0001). Forty-three patients improved their LVEF. Patients who improved their LVEF had a lower preoperative LVEF (P = 0.0001) and higher anterior wall viability (P = 0.03). Preoperative LVEF (odds ratio 0.89, 95% CI 0.83–0.95, P = 0.001) and left ventricular end systolic volume index (odds ratio 0.97, 95% CI 0.95–0.99, P = 0.015) were predictors of improvement in LVEF by multivariable logistic regression analysis.ConclusionsRecruitment of viable non functioning myocardium of the anterior wall is responsible for the improvement in ejection fraction. Low LVEF, non-remodeled left ventricle, and anterior wall viability predict improvement in ejection fraction after CABG. These criteria may help clinicians select patients who would benefit from surgical revascularization.