Prediction of myocardial viability for improvement in left ventricular ejection fraction after Coronary artery bypass graft

Abstract

Objective To define the relationship between the extent of viable myocardium and improvement in left ventricular ejection fraction function(LVEF) after Coronary artery bypass graft(CABG). Methods Total 46 patients received gated SPECT myocardial perfusion imaging(GSMPI) and18F-FDG-PET before CABG and GSMPI 3-6 months after CABG, the segments of viable myocardium were analyzed. Predictors for LVEF improvment after CABG were analyzed. Results LVEF improved group has more viable segments(5.4±2.6 vs 2.5±1.8, P<0.05)and less scar segments(0.3±0.6 vs 1.6±2.5, P<0.05)than that of LVEF non-improved group . Moreover, the number of viable segments is the independent factor for predicting LVEF improvement(OR=2.507, P<0.05). Furthermore, the optimal threshold value for the number of viable segments in predicting LVEF improvement was ≥4. Conclusion Patients with ≥4 viable segments improve LVEF after CABG, while patients with fewer such segments do not. The number of viable segments assessed by combining GSMPI and 18F-FDG-PET before CABG can effectively predict LVEF improvement after CABG. Key words: Myocardial metabolic imaging; Myocardial viability; Coronary artery bypass, off-pump; Left ventricular ejection fraction