Elevated serum creatinine is associated with 1-year mortality after acute myocardial infarction

Background Cardiovascular mortality is high in individuals with end-stage renal disease. However, less is known about the prognostic importance of moderate, renal insufficiency in patients with acute myocardial infarction. Methods We studied all patients with acute myocardial infarction admitted through the emergency department to an urban, academic hospital over 1 year. Patients were classified as having elevated (> 133 mumol/L [1.5 mg/dL]) or normal 133 mumol/L) serum creatinine at presentation. Results Of 483 patients, 22% had elevated creatinine and 786/. had normal creatinine. By 1 year, 46% of patients with elevated creatinine and 15% of patients with normal creatinine had died (P < .001). The unadjusted hazard ratio for 1-year mortality was increased in patients with elevated creatinine compared with those with normal creatinine (hazard ratio 3.85, 95% CI 2.61-5.67). After adjustment for baseline characteristics and treatment, the multivariable-adjusted hazard ratio for 1-year mortality remained increased in patients with elevated creatinine compared with those with normal creatinine (hazard ratio 2.40, 95% CI 1.55-3.72). There was an important modification of the prognostic value of creatinine by the presence of congestive heart failure at presentation (P value for interaction =.04). The adjusted hazard ratio for 1-year death associated with elevated creatinine compared with normal creatinine was 3.89 (95% CI 1.87-8.07) in patients without congestive heart failure and 1.92 (95% CI 1.10-3.36) in patients with congestive heart failure. Conclusions Elevated serum creatinine at presentation is associated with 1-year mortality, after acute myocardial infarction. Further study is needed to optimize treatment after myocardial infarction in this high-risk group.