Background: Only few studies specifically addressed the effect of timing of angiography and/or pre-treatment with a glycoprotein 2b/3a receptor blocker in patients with non-ST elevation acute coronary syndromes (ACS) who undergo invasive treatment.
Methods: In a 2-year period, 220 patients with non-ST elevation ACS, were randomized to early angiography without tirofiban pre-treatment (Early strategy) or to delayed angiography after 24-48h pre-treatment with tirofiban (Late strategy). The first 48h after admission, CKmb levels were measured and enzymatic infarct size (LDHQ(48)) was assessed by the area under the LDH release curve. When PCI was performed beyond 48h, CKmb was measured 6 and 12h afterwards.
Results: Median time to angiography was 6 (Early) and 50 (Late) hours. PCI was performed in 130 patients (59%). In these patients, a patent (TIMI 2 or 3 flow) culprit vessel was more often present in the Late group compared to the Early group (66% vs 82% p=0.05). In patients with an elevated CKmb (n=96, 44%), LDHQ(48)was significantly lower in patients who underwent angiography after pre-treatment with tirofiban (629+/-503U/L (Early) vs 432+/-441U/L (Late), p=0.02). No difference in clinical outcome between the groups was observed at 30 days follow-up.
Conclusion: This pilot study showed that a strategy of delayed angiography with concomitant pre-treatment with tirofiban is associated with improved angiographic outcomes and less initial enzyme release, compared to a strategy of immediate angiography without 2b/3a inhibitor pre-treatment. The use of an end point parameter, which assess total enzyme release over a given period of time, might be of special value in patients with non-ST elevation ACS, who undergo very early invasive treatment.