Duration of dual antiplatelet therapy after various drug-eluting stent implantation

Abstract

Objective: To evaluate efficacy and safety of long duration dual anti-platelet therapy i.e., >12months (L-DAPT) and short duration DAPT i.e., ≤12months (S-DAPT) after various drug-eluting stent (DES) implantation.

Methods: We searched Medline, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) to identify randomized controlled trials (RCTs) assessing the effect of L-DAPT versus S-DAPT after sirolimus-eluting (Cypher®); paclitaxel-eluting stents (Taxus®); zotarolimus-eluting (Endeavor®) and everolimus-eluting stents (Xience V®) implantation. Odds ratio (OR) and 95% confidence intervals (CI) were calculated using random-effects models. Subgroup analyses were performed comparing two second generation DES and for RCTs comparing S-DAPT and L-DAPT.

Results: We included six RCTs that randomized 19,012 patients to S-DAPT versus L-DAPT (4638 in first generation DES; 14,374 in second generation DES; 8099 EES; 4876 in ZES). Compared with L-DAPT, S-DAPT was associated with a higher rate of myocardial infarction (MI) and stent thrombosis (ST) after first [2.65 (1.88, 3.73) and 3.85 (2.14-6.93) respectively] and a higher rate of MI after second generation DES [1.33 (1.06, 1.67)]. There were no significant differences in the rates of all cause mortality, cardiovascular (CV) mortality and stroke with L-DAPT and S-DAPT after implantation of first [0.97 (0.52, 1.81); 1.19 (0.52-2.70); and 1.12 (0.36-3.52) respectively] and second generation DES [0.93 (0.69, 1.25); 0.93 (0.63, 1.36); and 0.58 (0.19, 1.75), respectively]. On further analysis of type of second generation DES, S-DAPT continues to show a higher rate of MI and ST after EES implantation [1.54 (1.11, 2.13) and 2.68 (1.20-5.94) respectively]; however there was no significant difference in the rate of MI and ST with S-DAPT and L-DAPT after ZES implantation [1.07 (0.44, 2.61) and 1.11(0.39, 3.13), respectively].

Conclusion: 1) Compared with L-DAPT, S-DAPT was associated with a higher rate of MI without any significant difference in the rate of all cause mortality, CV mortality and stroke after first and second generation DES. 2) Rate of ST was also higher with S-DAPT compared to L-DAPT after first generation DES implantation; however, it was not significantly different after second generation DES. 3) On further subgroup analysis of second-generation stent there was no significant difference in the rate of all cause mortality, CV mortality, MI, ST and stroke with S-DAPT and L-DAPT after ZES implantation. S-DAPT may be optimal for newer generation stents particularly ZES.

Keywords: Drug-eluting stents; Dual anti-platelet therapy.