Comparisons between ticagrelor and clopidogrel following percutaneous coronary intervention in patients with acute coronary syndrome: a comprehensive meta-analysis.

Background: The efficacy and safety of ticagrelor following percutaneous coronary intervention for patients with acute coronary syndrome remains unclear. This study sought to evaluate clinical outcomes of ticagrelor as part of dual-antiplatelet treatment for these patients. Methods: PubMed, MEDLINE, Embase, and other Internet sources were searched for eligible citations. The primary end point was major adverse cardiovascular and cerebrovascular events, consisting of cardiovascular death, myocardial infarction, and stroke. The secondary end point was the occurrence of definite/probable stent thrombosis (ST). The risk of bleeding was chosen to be the safety end point. Results: Eleven clinical trials - six randomized trials and five observational trials were finally analyzed. A tendency toward reduction in the risk of major adverse cardiovascular and cerebrovascular events was observed only with respect to ticagrelor (OR 0.83, 95% CI 0.66-1.03; P=0.091), which might have resulted from the lower risk of cardiovascular death (OR 0.78, 95% CI 0.68-0.89; P<0.001). The overall incidence of ST differed significantly between the ticagrelor group and the clopidogrel group (OR 0.74, 95% CI 0.59-0.93; P=0.009), but the risk of bleeding, regardless of major or minor bleeding, increased significantly. Conclusion: As part of dual-antiplatelet treatment following percutaneous coronary intervention, ticagrelor significantly reduced the risk of cardiovascular death and ST in acute coronary syndrome patients, but at the cost of bleeding. More powerful relevant randomized trials are still warranted to guide clinical decision-making.