Monitoring Serum Creatinine during the First Week after Myocardial Infarction May Help to Identify Patients Who Are at Highest Risk

Background: Small increases in creatinine over a specified period, defined as worsening renal function (WRF), have been assessed in heart failure (HF) patients as an independent prognostic marker. Nevertheless, the prognostic value of WRF in patients after acute myocardial infarction (AMI) is not well defined. Methods: WRF was defined as an increase in creatinine during hospitalization of ≥0.3 mg/dL above the admission value within 7 days. Patients were divided into early phase (1–4 days) and late phase (4–7 days). Our objectives were to determine the risk mortality associated with early phase and late phase WRF. Results: After 85 patients were excluded because of exclusion criteria (61 out of hospital cardiopulmonary arrest, 24 hemodialysis), 425 patients (men: 75.3%, age: 70.2 ± 13.3 y.o.) were enrolled. During mean follow-up 23.3 ± 16.6 months, WRF was observed in 104 (24.5%) of AMI survivors. Mortality was significantly higher in WRF group (25.0% vs 6.85%, P < .0001). WRF was independently associated with a higher risk of death (odds ratio = 3.82, 95% confidence intervals 1.62–9.18). Mortality was significantly higher in patient with early phase WRF (log-rank P < .0001) according to Kaplan-Meier analysis. Conclusions: Monitoring serum creatinine in patients during the first week was importance, not only in HF patients but also in AMI patients. Particularly, early phase WRF was a stronger predictor of mortality than late phase WRF.