A community survey of the potential use of thrombolytic agents for acute myocardial infarction.

We surveyed all patients admitted to nine community hospital coronary care units to determine what proportion could be candidates for thrombolytic therapy. During the 12-month study period, there were 4,115 admissions for possible acute myocardial infarction, and 1,076 (26%) had a discharge diagnosis of myocardial infarction. Patients with myocardial infarction had the following characteristics: 60% had ST elevation seen on the first ECG, 17% had ST depression without ST elevation, 75% were less than 75 years old, 75% had no contraindications to thrombolytic therapy, 78% arrived at hospital within six hours of onset of symptoms, and 94% arrived within 24 hours of symptoms. Criteria for administration of thrombolytic therapy can be grouped as restrictive (arrival within six hours of symptoms and ST elevation) or liberal (arrival within 24 hours of symptoms and ST elevation or ST depression). Applying these characteristics, 26% met restrictive criteria for treatment with thrombolytic therapy, and 36% met liberal criteria. Until liberal criteria (therapy up to 24 hours and ST depression) are convincingly shown to be of benefit, we believe clinicians should apply restrictive criteria to potential candidates for thrombolytic therapy.