Association of creatinine and creatinine clearance on presentation in acute myocardial infarction with subsequent mortality

Objectives We hypothesized that impaired renal function would also be associated with poorer clinical outcomes among patients with ST-segment elevation myocardial infarction (STEMI) treated with fibrinolysis. Background Previous studies have demonstrated that impaired renal function is associated with poorer clinical outcomes in the setting of unstable angina and non-STEMI and after percutaneous coronary intervention. Methods Data were drawn from the Thrombolysis In Myocardial Infarction (TIMI)-10, TIMI-14, and Intravenous nPA for the Treatment of Infarcting Myocardium Early (InTIME-II) trials. Results Within each TIMI risk score (TRS) for STEMI category (0 to 2, 3 to 4, ≥5), 30-day mortality increased stepwise among patients with normal (creatinine [Cr] ≤1.2 mg/dl), mildly (Cr >1.2 to 2 mg/dl), and severely (Cr >2.0 mg/dl) impaired renal function (p < 0.001) and in patients with normal (creatinine clearance [CrCl] ≥90 ml/min), mildly (60 to <90 ml/min), moderately (30 to <60 ml/min), and severely (<30 ml/min) impaired CrCl (p < 0.001). Impaired renal function was associated with increased mortality after adjusting for previously identified correlates of mortality (using Cr: odds ratio [OR] for mild impairment 1.52, 95% confidence interval [CI] 1.30 to 1.77, p < 0.001; OR for severe impairment 3.73, 95% CI 2.55 to 5.45, p < 0.001; using CrCl: OR for mild impairment 1.38, 95% CI 1.10 to 1.73, p = 0.006; OR for moderate impairment 2.06, 95% CI 1.59 to 2.66, p < 0.001; OR for severe impairment 3.81, 95% CI 2.57 to 5.65, p < 0.001). Conclusions In the setting of STEMI, elevated Cr and/or impaired CrCl on presentation is associated with increased mortality, independent of other conventional risk factors and TRS. This association does not appear to be mediated by reduced fibrinolytic efficacy among patients with impaired renal function or by the presence of congestive heart failure on presentation.