Objective: To determine the correlates of thrombolytic therapy use in a population-based sample of elderly patients hospitalized with acute myocardial infarction who were eligible for the therapy on presentation.
Design: Retrospective cohort study using data from medical charts and administrative files.
Setting: All acute care, nongovernmental hospitals in Connecticut.
Patients: A cohort of 3093 patients aged 65 years and older with a discharge diagnosis of acute myocardial infarction covered by Medicare from May 1992 to May 1993.
Results: Among the 753 patients with ST-segment elevation of 1 mm or more in at least 2 contiguous leads, left bundle branch block not known to be old, and no absolute contraindications to thrombolytic therapy who were not referred for direct angioplasty or bypass surgery, 419 patients (56%) did not receive thrombolytic therapy. The strongest predictors of not receiving thrombolytic therapy included advanced age, absence of chest pain, presentation more than 6 hours after the onset of symptoms, left bundle branch block, total ST-segment elevation of 6 mm or less, presence of Q waves, ST-segment elevation in only 2 leads, and altered mental status. Physicians documented why they did not administer thrombolytic therapy in 19% of the charts. Delay in presentation and increased age were the most common reasons cited. Among the subset of 261 patients who presented with chest pain and within 6 hours of symptoms, 197 (75%) received thrombolytic therapy.
Conclusions: Many eligible and ideal patients for thrombolytic therapy are not treated. Physicians are less likely to use thrombolytic therapy in eligible patients with characteristics associated with an increased risk of bleeding, lower-risk infarction, less certain diagnosis, less certain efficacy, or altered mental status. These findings suggest that the lack of treatment represents a clinical judgment rather than an inadvertent omission. In some cases, such as the lower use of thrombolytic therapy with older age, these judgments are not consistent with the published literature and may represent opportunities to improve care.