Efficacy of hirudin in reducing cardiovascular events in patients with acute coronary syndrome undergoing early percutaneous coronary intervention

AIMS: Although hirudin is superior to unfractionated heparin for prevention of death, myocardial infarction, or refractory ischaemia in patients with non-ST-elevation acute coronary syndrome, it is not clear whether hirudin is also of benefit in acute coronary syndrome patients undergoing early percutaneous coronary intervention. METHODS AND RESULTS: In the OASIS 2 trial, 10 141 patients with non-ST-elevation acute coronary syndrome were randomized to 72 h of intravenous hirudin or unfractionated heparin. Percutaneous coronary intervention was performed at the discretion of the investigator. One hundred and seventeen patients underwent percutaneous coronary intervention within the first 72 h ("early percutaneous coronary intervention"). In patients undergoing early percutaneous coronary intervention, hirudin compared with unfractionated heparin was associated with a significantly lower incidence of death or myocardial infarction at 96 h (6.4% vs 21.4%, OR 0.30; 95% CI: 0.10-0.88) and 35 days (6.4% vs 22.9%, OR 0.25; 95% CI: 0.07-0.86). In the unfractionated heparin group, death or myocardial infarction was significantly higher at 35 days in patients undergoing early percutaneous coronary intervention compared with those managed conservatively (22.9% vs 7.3%, OR 3.14, P<0.001) but this early percutaneous coronary intervention-related hazard was not observed in hirudin-treated patients (6.4% vs 6.8%, OR 0.94 P=1.0). A time-dependent covariate for percutaneous coronary intervention was not significant in a Cox regression model, suggesting a similar treatment benefit with hirudin before and after percutaneous coronary intervention. After adjustment for percutaneous coronary intervention propensity, the benefits of hirudin remained significant. There were three major bleeds in patients undergoing early percutaneous coronary intervention, all in patients randomized to hirudin. CONCLUSION: In patients with non-ST-elevation acute coronary syndrome undergoing early percutaneous coronary intervention, a direct thrombin inhibitor such as hirudin may be more effective than heparin in reducing the incidence of ischaemic complications.