Association of renal insufficiency with treatment and outcomes after myocardial infarction in elderly patients.

BACKGROUND Patients with end-stage renal disease are known to have decreased survival after myocardial infarction, but the association of less severe renal dysfunction with survival after myocardial infarction is unknown. OBJECTIVES To determine how patients with renal insufficiency are treated during hospitalization for myocardial infarction and to determine the association of renal insufficiency with survival after myocardial infarction. DESIGN Cohort study. SETTING All nongovernment hospitals in the United States. PATIENTS 130 099 elderly patients with myocardial infarction hospitalized between April 1994 and July 1995. MEASUREMENTS Patients were categorized according to initial serum creatinine level: no renal insufficiency (creatinine level < 1.5 mg/dL [<132 micromol/L]; n = 82 455), mild renal insufficiency (creatinine level, 1.5 to 2.4 mg/dL [132 to 212 micromol/L]; n = 36 756), or moderate renal insufficiency (creatinine level, 2.5 to 3.9 mg/dL [221 to 345 micromol/L]; n = 10 888). Vital status up to 1 year after discharge was obtained from Social Security records. RESULTS Compared with patients with no renal insufficiency, patients with moderate renal insufficiency were less likely to receive aspirin, beta-blockers, thrombolytic therapy, angiography, and angioplasty during hospitalization. One-year mortality was 24% in patients with no renal insufficiency, 46% in patients with mild renal insufficiency, and 66% in patients with moderate renal insufficiency (P < 0.001). After adjustment for patient and treatment characteristics, mild (hazard ratio, 1.68 [95% CI, 1.63 to 1.73]) and moderate (hazard ratio, 2.35 [CI, 2.26 to 2.45]) renal insufficiency were associated with substantially elevated risk for death during the first month of follow-up. This increased mortality risk continued until 6 months after myocardial infarction. CONCLUSIONS Renal insufficiency was an independent risk factor for death in elderly patients after myocardial infarction. Targeted interventions may be needed to improve treatment for this high-risk population.