Effect of Estimated Glomerular Filtration Rate on In-hospital Mortality in Patients with Acute Myocardial Infarction

Abstract

Objectives Determining the effect of the estimated glomerular filtration rate (eGFR) on in-hospital mortality among patients with acute myocardial infarction (AMI), to provide information for clinicians to develop a diagnosis and treatment plan for patients with AMI. Design: Adult patients with AMI from the Medical Information Mart for Intensive Care IV database were selected. Kaplan-Meier curves were used to determine the survival differences between patients in different eGFR groups. The relationship between the eGFR group and in-hospital mortality was estimated using the Cox regression model. Sensitivity analysis was then achieved by selecting gender and age strata. The nonlinear correlation showed the relationship between the eGFR values and the outcome, and the segmentation functions further calculated the optimal cutoff point. Results This study included 6,480 patients with AMI in intensive care units (ICUs). The patients with AMI were divided into two groups according to the eGFR value of 60 mL/min/1.73m² (low-eGFR group: eGFR < 60 mL/min/1.73m²; high-eGFR group: eGFR ≥ 60 mL/min/1.73m²). There was a significant difference in survival status between the two eGFR groups (P < 0.001). High-eGFR group was a protective factor for in-hospital mortality in patients with AMI in different percutaneous coronary intervention (PCI) and coronary artery bypass graft surgery (ByPass) groups (P < 0.001). High-eGFR group was a protective factor for in-hospital mortality in patients with AMI in different sex groups. The effect of the high-eGFR group on the outcome for those aged < 65 years was not statistically significant, while the high-eGFR group was a protective factor for the outcome for those aged ≥ 65 years. After excluding patients aged ≥ 65 years, eGFR values were strongly nonlinearly correlated with outcome (P = 0.006), and at this time, the best cutoff point for eGFR affecting the outcome was 31.60 mL/min/1.73m² (95% confidence interval = 23.23–39.97 mL/min/1.73m², P < 0.001). Conclusions Low-eGFR group in patients with AMI was associated with a higher in-hospital mortality risk. The optimal cutoff point of eGFR values for patients aged ≥ 65 years was 31.60 mL/min/1.73m².