Intensified Antiplatelet Treatment Reduces Major Cardiac Events in Patients with Clopidogrel Low Response: A Meta-analysis of Randomized Controlled Trials

Background: Clopidogrel low response (CLR) is an independent risk factor of adverse outcomes in patients undergoing percutaneous coronary intervention (PCI), and intensified antiplatelet treatments (IAT) guided by platelet function assays might overcome laboratory CLR. However, whether IAT improves clinical outcomes is controversial. Methods: Relevant trials were identified in PubMed, the Cochrane Library, and the Chinese Medical Journal Network databases from their establishment to September 9, 2014. Trials were screened using predefined inclusion criteria. Conventional meta-analysis and cumulative meta-analysis were performed using the Review Manager 5.0 and STATA 12.0 software programs. Results: Thirteen randomized controlled trials involving 5111 patients with CLR were recruited. During a follow-up period of 1–12 months, the incidences of cardiovascular (CV) death, nonfatal myocardial infarction (MI), and stent thrombosis were significantly lower in the IAT arm than in the conventional antiplatelet treatment arm (relative risk [RR] = 0.45, 95% confidence interval [CI]: 0.36–0.57, P < 0.000,01), whereas bleeding was similar between the two arms (RR = 1.05, 95% CI: 0.86–1.27, P = 0.65). Conclusions: IAT guided by platelet function assays reduces the risk of CV death, nonfatal MI, and stent thrombosis (ST) without an increased risk of bleeding in patients undergoing PCI and with CLR.