A Meta-Analysis of Randomized Clinical Trials Comparing Shorter (Less or Equal Than 6 Months) and Longer (More or Equal Than 12 Months) Dual Anti-Platelet Therapy Following Drug-Eluting Coronary Stents

CONTEXT: The optimal duration of dual anti-platelet therapy (DAPT) after the implantation of drug-eluting coronary stents (DES) is still the subject of ongoing debate. This meta-analysis was performed to investigate the optimal duration between ≤ 6 months and ≥ 12 months for DAPT after implantation of DES. EVIDENCE ACQUISITION: This study was conducted at the department of cardiology, the first college of clinical medical sciences, institute of cardiovascular diseases of Three Gorges university during December 2014. Pub-med, Cochrane, Scopus and clinicaltrials.gov databases were searched for papers published until December 2014. Searches of the above databases included terms “dual anti-platelet therapy” and “myocardial infarction (MI)” and “drug-eluting stents (DES)”. All the searched literatures were limited to Randomized Controlled Trials (RCTs). Quality assessments were evaluated with the Jadad quality scale. Data were extracted by two independent observers (FZ and YC). For all analyses, the 95% confidence interval (CI) was calculated and heterogeneity of the studies was analyzed using I2 statistics. RESULTS: Five RCTs with 9979 participants satisfying the inclusion criteria were finally analyzed. Overall, there were 4993 patients with shorter duration of DAPT and 4986 patients with a longer treatment. Clopidogrel was the used P2Y12 receptor inhibitor in all five RCTs. On one hand compared to shorter duration (≤ 12 months) DAPT, longer duration (≥ 12 months) did not reduce risk of mortality, cardiac death, cerebrovascular accidents, myocardial infarction and stent thrombosis (pooled OR 1.03, 95% Confidence Interval (CI) 0.80 - 1.32, P = 0.85, I(2) = 0%; pooled OR 0.91, 95% CI 0.64 - 1.29, P = 0.60, I(2) = 0%; pooled OR 0.84, 95% CI 0.50 - 1.42, P = 0.51, I(2) = 0%; pooled OR 1.17, 95% CI 0.87 - 1.58, P = 0.29, I(2) = 0%; pooled OR 1.36, 95% CI 0.81 - 2.29, P = 0.24, I(2) = 0%). On the other hand, longer duration (≥ 12 months) could also increase the risk of thrombolysis in myocardial infarction (TIMI) major bleeding (pooled OR 0.50, 95% CI 0.29 - 0.85, P = 0.01, I(2) = 0%). CONCLUSIONS: Regarding the efficacy outcomes of the patients after DES implantation, no differences were found between shorter (≤ 6 months) and longer (≥ 12 months) duration of DAPT. What is worse is that longer duration (≥ 12 months) was associated with increased risk of bleeding complications.