Background: Optimal antithrombotic therapy after percutaneous coronary intervention (PCI) is currently undefined in patients requiring long-term anticoagulation. Previous studies comparing triple therapy (TT) of warfarin, aspirin and clopidogrel with standard dual therapy (DT) of aspirin and clopidogrel have yielded conflicting results. Meta-analysis of these studies was performed to evaluate safety and efficacy of TT.
Methods: A total of 1482 patients from 6 studies were analyzed using the Mantel-Haenszel random effect model to extract incidence of major bleeding. The secondary end point assessed by three of these studies was major adverse cardiac events (MACEs: cardiovascular death, myocardial infarction and thromboembolic complications). The incidence of MACEs was computed using the Mantel-Haenszel fixed effect model. Combined relative risks (RRs) across all of the studies and the 95% confidence intervals (CIs) were determined. A two-sided alpha error <0.05 was considered statistically significant.
Results: Baseline characteristics were similar in both groups. Compared with patients receiving DT, the risk of major bleeding was significantly higher in the TT group (RR: 2.74, CI: 1.08-6.98; p=0.034). However, risk of MACE was significantly lower in the TT group (RR: 0.72, CI: 0.56-0.98; p=0.014).
Conclusion: In patients requiring long-term anticoagulation after PCI, TT may be superior to DT in reducing the incidence of MACEs, however risk of major bleeding complications is increased significantly.