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 μmol/L [1.5 mg/dL]) or normal (≤133 μmol/L) serum creatinine at presentation. Results: Of 483 patients, 22% had elevated creatinine and 78% 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 wos increased in patients with elevated creatinine compared with those with normal creatinine (hazord 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 odjusted 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 inforction in this high-risk group.