Mid-term results of coronary bypass graft surgery in patients with ischaemic left ventricular systolic dysfunction and no detected myocardial viability

Abstract

OBJECTIVES There are concerns about effects of surgical revascularization on patients with ischaemic systolic dysfunction when no signs of myocardial viability have been detected by nuclear imaging preoperatively. We reviewed our data to determine the efficacy of coronary bypass graft in this special patient cohort. METHODS A retrospective review with prospectively collected clinical data was conducted on 87 consecutive patients between 2000 and 2012 whose left ventricular ejection fraction was less than 40%. All patients received positron emission tomography examination before undergoing coronary artery bypass graft and showed no signs of myocardial viability. Improvements in ejection fraction, postoperative re-examination of myocardial viability by nuclear imaging and freedom from major cardiac events were observed. Survival was calculated using Kaplan-Meier analysis. RESULTS The 30-day mortality rate was 7%. Ejection fraction improvement (defined as over 5%) was observed in 13 (16%) patients within 6 months postoperatively. Ejection fraction improvement was observed in 46 (58%) patients by the end of the first year and 50 (63%) patients by the second year. It was noted that 25 (32%) and 43 (54%) patients progressed to heart functional class I or II at 1 and 5 years, respectively. Positron emission tomography examination showed enhanced myocardial viability in the non-viable ventricular wall segment in 53 (67%) patients at 1 year. Freedom from major adverse cardiac events was observed in 56 (71%) patients at 1 year and 47 (60%) patients at 5 years. Survival rates were 82 and 66% at 1 and 5 years, respectively. CONCLUSIONS Coronary artery bypass graft proved to be a positive choice of treatment for patients with severe ischaemic systolic dysfunction when there was no viable myocardium detected through nuclear imaging.