Objective: To decrease acute myocardial infarction (AMI) and incidence of other cardiovascular event after drug-eluting stent (DES) implantation, so as to prevent non-acute stent thrombosis.
Methods: Patients who had undergone percutaneous coronary intervention with DES from January 2005 to September 2008 were enrolled. All patients were randomly assigned into two groups with different treatment protocols for anti-thrombosis. The patients in control group were treated with aspirin and clopidogrel for anti-thrombosis (double anti-treatment), while those in observation group were treated with tirofiban and warfarin on top of basic treatment with double anti-thromotic drugs. The latter group of patients received warfarin in addition for 6 months, with the international normalized ratio (INR) maintained at 1.5-2.0. The patients in both groups were followed up at 1-3 months after the treatment, and the deadline was October 2012. Stent thrombosis was assessed by the definition of Dublin for Academic Research Consortium. The main ending point indexes were main adverse cardiac and cerebral events (MACCE), and the secondary ending point indexes were incidence of bleeding and other adverse events.
Results: A total of 505 consecutive patients treated with DES implantation were enrolled, 245 in the observation group while 260 in the control. The rates of MACCE at 1- 48 months after operation in observational group were significantly lower than those in control group (1 month: 0.41% vs. 3.08%, 2-6 months: 0 vs. 2.31%, 7-12 months: 0.82% vs. 4.23%, 13-24 months: 1.22% vs. 8.85%, 25- 48 months: 2.04% vs. 12.31%, all P<0.05). Cardiac death (13-24 months: 0.41% vs. 3.08%, 25-48 months: 0.82% vs. 4.23%), non-lethal acute myocardial infarction unrelated with target vessels (25-48 months: 0.41% vs. 3.08%), and rates of revascularization of target vessels (13-24 months: 0.41% vs. 3.08%, 25-48 months: 0.82% vs. 4.23%) in observation group were significantly lower than those in the control group (all P<0.05). The rates of sub-acute stent thrombosis, late stent thrombosis, and very late stent thrombosis in observation group were significantly lower than those in control group (0 vs. 2.31%, 0.82% vs. 4.23%, 1.63% vs. 8.46%, all P<0.05). The rate of bleeding in observational group was a litter higher than control group (3.27% vs. 1.54%, P=0.167) and no severe bleeding occurred. Other severe adverse events were not found in both groups.
Conclusion: The results indicate that tirofiban and warfarin combined with aspirin and clopidogrel could reduce the rates of MACCE and bleeding, and it could prevent non-acute stent thrombosis safely and effectively after percutaneous coronary intervention with DES.