BackgroundThe impact of exercise tolerance on renal function change after acute myocardial infarction (AMI) is not clear. ObjectivesThe present study aimed to elucidate the effect of peak exercise oxygen uptake (VO2) levels on longitudinal changes in renal function up to 1 year after onset of AMI. MethodsThis retrospective longitudinal study enrolled 198 AMI patients. Symptom-limited cardiopulmonary exercise testing was performed at completion of early Phase II cardiac rehabilitation, and peak VO2 levels were defined as the primary exposure factor. The estimated glomerular filtration rates (eGFRs) at baseline, 3 months, 6 months and 1 year were collected. Generalized estimating equation (GEE) models were used to test the longitudinal effect of peak VO2 levels on within-patient changes in eGFR. ResultsPatients were stratified into tertile groups (Low group, 12.3 ± 1.3 mL/kg/min; Mid group, 15.3 ± 0.7 mL/kg/min; and High group, 19.1 ± 2.3 mL/kg/min) according to peak VO2 levels. The slopes of eGFR over 1 year in the Low (p = 0.024) and Mid groups (p = 0.037) were lower compared to the High group. The Low group had a significantly higher odds ratio of experiencing rapid renal function decline than the High group (odds ratio, 2.87; p = 0.012). ConclusionsThere was a significant effect of lower peak VO2 on rapid decline in renal function after AMI. Our findings suggest that the coexistence of exercise intolerance may be a novel risk factor for rapid decline in renal function after AMI.