Comparison of 5-Year Outcomes After Coronary Artery Bypass Grafting in Heart Failure Patients With Versus Without Preserved Left Ventricular Ejection Fraction (from the CREDO-Kyoto CABG Registry Cohort-2)

Heart failure (HF) with reduced left ventricular (LV) ejection fraction (HFrEF) is regarded as an independent risk factor for poor outcomes after coronary artery bypass grafting (CABG). However, the impact of HF with preserved EF (HFpEF) still has been unclear. We identified 1,877 patients who received isolated CABG of 15,939 patients who underwent first coronary revascularization enrolled in the CREDO-Kyoto (Coronary REvascularization Demonstrating Outcome Study in Kyoto) Registry Cohort-2. Of them, 1,489 patients had normal LV function (LVEF >50% without a history of HF; Normal group), 236 had HFrEF (LVEF <= 50% with HF), and 152 had HFpEF (LVEF >50% with HF). Preoperative LVEF was the lowest in the HFrEF group (62 +/- 12%, 36 +/- 9%, and 61 +/- 7% for the Normal, HFrEF, and HFpEF groups, respectively; p <0.001). Unadjusted 30-day mortality rate was the highest in the HFrEF group (0.5%, 3.0%, and 0.7%; p = 0.003). However, cumulative incidences of all-cause death at 5-year was the highest in the HFpEF group (14%, 27%, and 32%, respectively; p <0.001). After adjusting confounders, the risk of all-cause death in the HFpEF group was greater than the Normal group (hazard ratio [BR] 1.42; 95% confidence interval [CI] 1.02 to 1.97; p = 0.04). The risk of all-cause death was not different between the HFpEF and the HFrEF groups (HR 0.88; 95% CI 0.61 to 1.29; p = 0.52). In addition, the risks of cardiac death and sudden death in the HFpEF group were greater than the Normal group (HR 2.14, 95% CI 1.32 to 3.49, p = 0.002; and HR 3.60, 95% CI 1.55 to 8.36, p = 0.003, respectively), and the risks of those end points were not different between the HFrEF and the HFpEF groups. Despite low 30-day mortality rate after CABG in patients with HFpEF, HFpEF was associated with high risks of long-term death and cardiovascular events. Patients with HFpEF, as well as HFrEF, should be carefully operated and followed up. (C) 2015 Elsevier Inc. All rights reserved.