PROSPECTIVE EVALUATION OF ELIGIBILITY FOR THROMBOLYTIC THERAPY IN ACUTE MYOCARDIAL-INFARCTION

Objective-To determine the proportion of patients presenting with acut e myocardial infarction who are eligible for thrombolytic therapy. Des ign-Cohort follow up study. Setting-The four coronary care units in Au ckland, New Zealand. Subjects-All 3014 patients presenting to the unit s with suspected myocardial infarction in 1993. Main outcome measures- Eligibility for reperfusion with thrombolytic therapy (presentation wi thin 12 hours of the onset of ischaemic chest pain with ST elevation g reater than or equal to 2 mm in leads V1-V3, ST elevation greater than or equal to 1 mm in any other two contiguous leads, or new left bundl e branch block); proportions of (a) patients eligible for reperfusion and (b) patients with contraindications to thrombolysis; death (includ ing causes); definite myocardial infarction. Results-948 patients had definite myocardial infarction, 124 probable myocardial infarction, an d nine ST elevation but no infarction; 1274 patients had unstable angi na and 659 chest pain of other causes. Of patients with definite or pr obable myocardial infarction, 576 (53.3%) were eligible for reperfusio n, 39 had definite contraindications to thrombolysis (risk of bleeding ). Hence 49.7% of patients (537/1081) were eligible for thrombolysis a nd 43.5% (470) received this treatment. Hospital mortality among patie nts eligible for reperfusion was 11.7% (55/470 cases) among those who received thrombolysis and 17.0% (18/106) among those who did not. Conc lusions-On current criteria about half of patients admitted to coronar y care units with definite or probable myocardial infarction are eligi ble for thrombolytic therapy. Few eligible patients have definite cont raindications to thrombolytic therapy. Mortality for all community adm issions for myocardial infarction remains high.