Impact of left ventricular ejection fraction on outcomes in non-ST-segment elevation myocardial infarction patients with and without chronic kidney disease

Abstract Background Given the importance of renal and cardiac function in the prognosis of coronary artery disease, we compared 3-year clinical outcomes based on the degree of left ventricular ejection fraction (LVEF) in patients with non-ST-segment elevation myocardial infarction (NSTEMI) with or without chronic kidney disease (CKD). Methods A total of 4567 patients diagnosed with NSTEMI were enrolled from the Korea Acute MI Registry-NIH dataset and stratified into two groups: the CKD (1270 patients) and non-CKD (3297 patients) groups. Each group was further classified into heart failure (HF) with reduced EF (HFrEF), HF with mildly reduced EF (HFmrEF), and HF with preserved EF (HFpEF) subgroups. The primary outcome was all-cause death. Results In both CKD and non-CKD groups, the adjusted rates of all-cause death (both p 0.001) and cardiac death (CD, both p 0.001) in the HFrEF subgroup were significantly higher than in the HFmrEF and HFpEF subgroups. However, within the CKD group, all-cause death rate was comparable between the HFmrEF and HFpEF subgroups. In contrast, within the non-CKD group, the rates of all-cause death (p = 0.005) and CD (p = 0.008) were significantly higher in the HFmrEF subgroup compared to the HFpEF subgroup. The increased all-cause death in the CKD group, relative to the non-CKD group, within the HFpEF subgroup contributed to these outcomes. Conclusions Regardless of CKD status, the HFrEF subgroup showed higher mortality rates compared with the HFmrEF and HFpEF subgroups. However, the mortality rate differed between the HFmrEF and the HFpEF subgroups in both the CKD and the non-CKD groups.