The impact of renal function on the three-year outcomes in patients with myocardial infarction with nonobstructive coronary arteries

Background: Due to limited data availability, we compared the 3-year outcomes of patients with acute myocardial infarction (AMI) and nonobstructive coronary arteries (MINOCA) and those with obstructive coronary arteries (MIOCA) according to renal function. Methods: From a final cohort of 10,774 patients with AMI were classified into 2 groups: the chronic kidney disease (CKD) group (estimated glomerular filtration rate <60 mL/min/1.73 m², 2,854 patients; MINOCA, 123; MIOCA, 2,731) and the non-CKD group (7,920 patients; MINOCA, 256; MIOCA, 7,664). The primary outcome was the 3-year all-cause death rate, and the secondary outcomes included cardiac death (CD), non-CD death (NCD), recurrent myocardial infarction (MI), and any revascularization. Results: In both the CKD and non-CKD groups, the adjusted in-hospital mortality, 3-year all-cause death, CD, and recurrent MI rates were similar between the MINOCA and MIOCA groups, but the adjusted 3-year any revascularization rates were significantly higher in the MIOCA group than in the MINOCA group. Characteristically, in the CKD group, the adjusted 3-year NCD rate (P = 0.032) was higher in the MINOCA group than in the MIOCA group, and sepsis was the main cause of NCD in this group. In both the MINOCA and MIOCA groups, all-cause death and NCD were significantly higher in the CKD group than in the non-CKD group. Conclusions: Regardless of renal function, the MINOCA and MIOCA groups had comparable mortality rates. However, patients with MINOCA and CKD had higher NCD rates. Close monitoring of renal function and enhanced strategies are required to reduce mortality in patients with MINOCA.