Short Outcomes Of Early Tirofiban In Patients With Moderate And High Risk Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

Background and ObjectiveFor patients with moderate and high risk non-ST-segment elevation acute coronary syndromes (NSTEACS) who undergo early invasive treatment strategies, current guidelines recommend early administration of platelet glycoprotein (GP)Ⅱb/Ⅲa inhibitors. However, the optimal timing is undefined. Now there are two strategies of tirofiban in clinical trial, early tirofiban or selectively provisional usage of tirofiban, and there is no clinical trial to confirm which is more beneficial to ACS patients. To study the optimal timing of tirofiban administration and the benefits and safety of early tirofiban, this study observed short outcomes of early tirofiban in patients with moderate and high risk NSTEACS undergoing percutaneous coronary interventions (PCI) by directly comparing three strategies including early tirofiban, downstream tirofibn and no tirofiban. Methods118 confirmed moderate and high risk NSTEACS patients undergoing PCI were randomized into early tirofiban group (n=45,tirofiban was used at least 4 hours before PCI), downstream tirofiban (n=47, just after PCI) and no tirofiban group (n=26, tirofiban was not used before and after PCI). Patients who had provisional usage of tirofiban were excluded from the downstream tirofiban and no tirofiban groups. Asparin, clopidogrel, statins and low molecular weight heparin (LMWH) were administrated to all patients. Platelet aggregation rate (PAR), MB isoenzyme of creatine kinase(CK-MB)and TIMI 3 flow rate before and after PCI,incidences of 7-day,30-day and 90-day major adverse cardiac events(MACE, death, reinfarction, recurrent myocardial ischemia), acute thrombosis events, bleeding complications and thrombocytopenia were recorded.ResultsTime of tirofiban administration was 12.4 hours earlier in the early group than in the downstream one. Platelet aggregation was inhibited more than 90 percent when tirofiban was administered for 12 hours, and PAR came to baseline level when stopped for 6 hours. The value of CK-MB was significantly lower after PCI in early tirofiban group and downstream tirofiban (10.40±4.10 vs 13.18±6.95 vs 19.05±13.01,P=0.009), whereas there was no significant difference between the two groups of tirofiban administration. Before PCI, TIMI 3 flow rate of the target vessel was significantly higher in early tirofiban group than that in downstream and no tirofiban groups (50.8% vs 28.8% vs 34.3%,P=0.046).However, TIMI 3 flow rate after PCI was not significantly different between the three groups (98.4% vs 94.2% vs 94.3%,P=0.278).The occurrence of acute thrombosis events was higher in downstream tirofiban (8.5% vs 0 vs 0,P=0.044).There was no significant difference between the three groups in the 7-day,30-day and 90-day occurrences of MACE, through the incidences were consistently lower in early tirofiban. No GUSTO severe or moderate bleeding was observed. The incidences of slight bleeding complications and thrombocytopenia were not significantly different in the three groups.ConclusionAmong patients with moderate and high risk NSTEACS pretreated with aspirin and clopidogrel, early tirofiban was associated with potently inhibited of platelet aggregation, a better patency(TIMI 3 flow) before PCI, attenuated minor myocardial damage, the lower occurrence of acute thrombosis events and the tendency of reducing incidences of 7-day,30-day and 90-day MACE.6 to 12 hours earlier use of tirofiban before PCI is a safe and effective strategy, and it would be optimal timing of tirofiban in clinical practice in the future. However, larger studies are warranted to evaluate the benefits of early tirofiban in terms of long-term follow-up.