Long-term outcome of surgical revascularization in patients with reduced left ventricular ejection fraction—a population-based cohort study

Abstract

Background Surgical revascularization is an established indication for patients with advanced coronary artery disease and reduced left ventricular ejection fraction (LVEF). Long-term outcomes for these patients are not well defined. We studied the long-term outcomes of patients with ischaemic cardiomyopathy who underwent surgical revascularization in a well-defined nationwide cohort. Materials and methods A retrospective study on 2,005 patients that underwent isolated coronary artery bypass grafting (CABG) in Iceland between 2000–2016. Patients were catagorized into two groups based on their preoperative LVEF; LVEF ≤35% (n = 146, median LVEF 30%) and LVEF >35% (n = 1859, median LVEF 60%). Demographics and major adverse cardiac and cerebrovascular events (MACCE), were compared between groups along with cardiac-specific and overall survival. Mean follow-up was 7.6 years. Results Demographics were similar in both groups regarding age, gender, and most cardiovascular risk factors. However, patients with LVEF ≤35% more often had diabetes, renal insufficiency, chronic obstructive pulmonary disease and a previous history of myocardial infarction. Thirty-day mortality was four times higher (8% vs 2%, p < 0.001) in the LVEF ≤35%-group compared to controls. MACCE-free survival was 83% and 62% at 1 and 5 years for LVEF ≤35%-group compared to 94% and 82% for the control group. Overall survival was also significantly lower in the same groups, or 87% and 69% (p < 0.001) compared to 98% and 91% (p < 0.001), at 1 and 5 years respectively. Conclusions A good long-term outcome after CABG can be expected for patients with reduced LVEF, however, their survival is still significantly inferior to patients with normal ventricular function.

Predicting outcomes in patients with low ejection fraction undergoing coronary artery bypass graft

“…Yoo et al [18] assessed 476 patients with an LVEF ≤ 35 % who underwent CABG and demonstrated that ≥ moderate MR, lower eGFR, and LV wall thinning were independent predictors of death. Likewise, Hillis et al showed that higher age and lower eGFR are strong predictors of mortality in reduced LVEF (≤35) [19] , which was comparable to the results of a study by Brynjarsdottir et al including advanced age, DM, chronic kidney disease (CKD), COPD, current smoking, NYHA classification III or IV, emergency procedure and longer skin-to-skin time [11] . In a similar study by DeRose et al, higher age, PVD, emergency operation, and chronic obstructive pulmonary disease were independent predictors of higher mortality in patients with LVEF ≤ 25 [20] .…”

“…Generally, higher five-year mortality rates have been reported across the literature, varying significantly from 20 % to 40 % [4] , [28] , [29] . Moreover, Brynjarsdottir et al reported 38 % five-year MACCE for patients with LVEF ≤ 35 [11] . Most studies have evaluated only mortality risk without investigating the adverse events.…”

“…Nevertheless, the predictors vary substantially in different populations and settings. For instance, advanced age, diabetes (DM), chronic obstructive pulmonary disease (COPD), and current smoking increased the risk of all-cause death and (MACCE) [11] .…”