Effectiveness of thrombolytic therapy for acute myocardial infarction in the elderly: cause for concern in the old-old.

BACKGROUND National guidelines have encouraged increased use of thrombolytic therapy for elderly patients with acute myocardial infarction (AMI). However, evidence supporting thrombolytic therapy in patients 75 years and older is lacking. In a retrospective cohort study of 2659 elderly AMI patients, we determined the association between thrombolytic use and in-hospital mortality by age and among patients with or without absolute or relative contraindications to thrombolytic treatment. METHODS We abstracted the medical records of 2659 elderly patients admitted with AMI at 37 Minnesota community hospitals between 1992 and 1996. The main outcome measure was in-hospital mortality, controlling for demographic, clinical, comorbidity, and severity-of-illness variables. RESULTS Sixty-three percent of 719 eligible patients received thrombolytic therapy. Twenty-seven percent of thrombolytic recipients had absolute contraindications to treatment. Patients receiving thrombolytic agents had fewer and less severe comorbidities than those not receiving thrombolytic therapy. There was a 4% increase in the odds of death for every 1-year increase in age for all thrombolytic recipients vs nonrecipients (odds ratio [OR], 1.04 per year; 95% confidence interval [CI], 1.01-1.08; P =.03). Among patients with 1 or more contraindication, the OR for death associated with thrombolytic use was 1.57 (95% CI, 1.03-2.40; P =.04). The adjusted odds of death among eligible thrombolytic recipients (vs nonrecipients) increased significantly with age (OR, 1.08 per year; 95% CI, 1.02-1.14; P =.008). Among eligible patients aged 80 to 90 years, the predicted odds of death among thrombolytic recipients vs nonrecipients was 1.4. Among eligible patients younger than 80 years, thrombolytic use was associated with reduced mortality. CONCLUSIONS Our findings suggest the need for more research on the effectiveness of thrombolytic therapy for AMI patients 75 years and older and for more careful selection of elderly patients for this treatment.