Background: Despite their proven beneficial effects and inclusion in the guidelines, glycoprotein (GP) IIb/IIIA blockers are underused in daily practice in patients with non ST-segment elevation acute coronary syndrome (NSTE ACS). This study combines the data from two randomized controlled trials, comparing routine upstream versus selective down stream use of tirofiban in patients with NSTE ACS.
Methods: Inclusion criteria for both studies (ELISA-1 and 2) were angina pectoris, with ST depression >1 mm and or a positive cardiac biomarkers. All patients were scheduled for coronary angiography. The primary and secondary end points for both studies were enzymatic infarct size (LDHQ48) and initial TIMI flow of the culprit lesion respectively.
Results: From August 2000 to January 2005, 273 patients were randomized to routine upstream tirofiban and 275 patients to selective down stream use of tirofiban. Selective down stream tirofiban was used in 55 patients (20%). Patients in the upstream group more often had a patent culprit lesion (65% vs. 50%, P=0.003) and a significantly smaller enzymatic infarct size, LDHQ48 median (25-75%): 125 (55-309) vs. 189 (68-504) IU/l, P=0.006 as compared to the selective down stream group. Subgroup analysis showed that routine upstream tirofiban was particularly effective in males, patients with a positive troponin on admission and in those not pretreated with clopidogrel.
Conclusion: Routine upstream GP IIb/IIIa is mainly effective in patients with elevated troponin on admission and those not pretreated with clopidogrel. Large scale randomized trials are needed to evaluate the effect of GP IIb/IIIa blockers on top of clopidogrel pretreatment on major adverse cardiac events.