The Western Washington myocardial infarction registry and emergency department tissue plasminogen activator treatment trial

Abstract

This study comprised a registry and an emergency department treatment trial using recombinant tissue plasminogen activator. During 1 year, 1,028 patients with documented acute myocardial infarction (AMI) were evaluated for eligibility for thrombolytic therapy. Of these, 221 patients (22%) were eligible for thrombolytic therapy under currently accepted criteria, 175 (79%) of them were correctly identified by emergency department physicians for thrombolytic therapy, and 160 were enrolled in the trial. Only 3 patients (2%) enrolled by emergency department physicians did not subsequently evolve documented AMI. In all, 807 patients (78%) Were ineligible for thrombolytic therapy: 335 (33%) because of ≥1 contraindications, 364 (36%) because of nondiagnostic electrocardiograms on presentation, and 105 (10%) because of age >75 years, or >6 hours of chest pain at presentation, or both. Mortality in treated patients at 14 days was 5.6%, and survival at 1 year was 92%. The mean time from hospital arrival to thrombolytic treatment was 55 ± 27 minutes. Initial management of AMI with recombinant tissue plasminogen activator in the emergency department provided rapid and safe treatment comparable to that reported in trials that started treatment in the coronary care unit. The proportions of eligible patients could be increased from 1 in 5 to 1 in 3, if patients currently excluded only because of age >75 years or because of >6 hours of chest pain were offered treatment.