Incidence of high-risk acute coronary syndromes and eligibility for glycoprotein IIb/IIIa inhibitors among patients admitted for possible myocardial ischemia

Objective Recent studies have demonstrated that glycoprotein (GP) IIb/IIIa inhibitors can reduce cardiac events in patients with acute coronary syndromes (ACS). However, little is known about how many patients are actually eligible for treatment. Our purpose was to determine how many patients admitted for possible myocardial infarction (MI) meet GP IIb/IIIa inhibitor treatment criteria. Methods Patients admitted for possible MI who underwent a standard protocol that included serial sampling of total creatine kinase (CK), CK-MB, and troponin I (TnI) were retrospectively assigned to different treatment algorithms on the basis of criteria from GP IIb/IIIa inhibitor trials: an electrocardiogram (ECG) consistent with acute MI or ischemia, and myocardial marker elevations. Elevated CK-MB was considered diagnostic of MI. High-risk ACS was defined as ischemic ECG changes or troponin elevations without CK-MB elevations. Results A total of 2179 patients were admitted for MI exclusion. MI was identified in 304 patients (14.0%) (123 ST-elevation, 49 ischemic ECG, 132 nonischemic ECG). Another 273 patients (12.5%) without CK-MB criteria for MI met high-risk ACS criteria (172 ischemic ECG, 120 TnI elevations). Ischemic ECGs or elevated myocardial markers identified 454 (21%) patients as eligible for treatment. Inclusion of patients with ST elevation increased eligibility to 26.5%. Of the 454 non-ST-elevation ACS patients, 340 (74%) were identified early by the ECG or the initial markers. Conclusions A large proportion of patients admitted for possible MI met criteria for treatment with GP IIb/IIIa inhibitors. The non-ST-elevation ACS group was >3 times larger than the ST-elevation MI group. These findings have important implications for treatment of patients with ACS. (Am Heart J 2002;143:70-5.)