Predictive Effect of Renal Function on Clinical Outcomes in Older Adults With Acute Myocardial Infarction: Results From an Observational Cohort Study in China

Background: The impact of estimated glomerular filtration rate (eGFR) on the risk of death and cardiovascular events in individuals with acute myocardial infarction (AMI) is less well established, particularly in the old Chinese population. The aim of this study was to investigate the association of eGFR with clinical outcomes among older subjects with AMI. We further developed a nomogram for the prediction of 1- and 3-year survival in this population. Methods: A cohort of 2,366 AMI subjects aged over 60 years in 2013–2020 were enrolled in the Cardiovascular Center of Beijing Friendship Hospital Database (CBD) Bank. Outcomes including cardiovascular (CV) death, all-cause death, non-fatal myocardial infarction (MI), non-fatal stroke, revascularization, and cardiac rehospitalization were collected overall and by eGFR category at baseline. eGFR was estimated by the Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI). Subjects were categorized into four groups according to quartiles of eGFR: ≤ 63.02, 63.03–78.45, 78.46–91.50, >91.51 ml/min/1.73 m(2). Hazard ratios (HRs), corresponding 95% confidence intervals (CIs) as well as the nomogram were assessed using Cox regression models. Validation of the nomogram was estimated by discrimination and calibration. Results: Incidence rates and multivariable-adjusted hazard ratios of CV and all-cause death decreased significantly across quartiles of eGFR over a median follow-up time of 36.7 months. In adjusted analysis, compared with eGFR ≤ 63.02 ml/min/1.73 m(2), patients with eGFR of 63.03–78.45, 78.46–91.50, >91.51 ml/min/1.73 m(2) experienced decreased risks of CV death [respective HRs of 0.58 (95% CI, 0.38–0.90), 0.61 (95% CI, 0.38–0.99), and 0.48 (95% CI, 0.25–0.90); all p < 0.05] and all-cause death [respective HRs of 0.64 (95% CI, 0.47–0.88), 0.61 (95% CI, 0.42–0.88), and 0.54 (95% CI, 0.35–0.84); all p < 0.05]. Age, eGFR quartiles, BMI, glycated hemoglobin, LVEF, LM/multi-vessel disease, angiotensin-converting enzyme inhibitors (ACEIs), or angiotensin receptor blockers (ARBs) prescribed at discharge were associated with all-cause death. The developed model predicted 1- and 3-year probability of survival, which performed well in both discrimination and calibration. Conclusion: In older patients with AMI, early identification of eGFR reduced and cardiovascular risks management may prevent poor clinical outcomes.