The TIMI 9 Registry set out to assess the management strategies and outcomes of an unselected group of patients with acute myocardial infarction presenting with ST segment elevation (STEMI). Demographic, procedural, and outcome data were collected from 840 consecutive patients with STEMI at 20 hospitals in United States and Canada between February and September 1994. Of them, 60% were treated with thrombolytic therapy, 9% with primary angioplasty, and 31% did not receive reperfusion therapy. Patients who did not receive reperfusion therapy were older, more likely female, and had a higher prevalence of prior myocardial infarction, congestive heart failure, higher Killip class on admission, and longer time from onset of symptoms to presentation. In evaluating the standard contraindications for fibrinolysis, approximately 10% in the thrombolytic group, 40% in the primary percutaneous coronary intervention (PCI), and 34% of those not receiving reperfusion therapy had at least one of these characteristics. Of those patients treated with fibrinolysis, only 20% met the National Heart Attack Alert Program goal of door-to-drug time < or =30 minutes. Likewise, of those treated with primary PCI, only 30% had PCI performed within < or =90 minutes. In-hospital mortality was significantly higher for patients not treated with reperfusion therapy (18.9%), compared with patients treated with fibrinolysis (7.6%) and those treated with primary PCI (10.5%) (P < 0.001). Thus, we found that reperfusion therapy was underused, with only 69% of patients with STEMI receiving this proven treatment, and of those only 25% treated within the recommended timeline. These data suggest that there is room for improvement in the management of these patients.