Optimal Duration of Dual Antiplatelet Therapy after Drug-Eluting Stents: Meta-Analysis of Randomized Trials.

INTRODUCTION

The optimal duration of dual antiplatelet therapy (DAPT) after drug-eluting stent implantation (DES) is not certain. The AHA/ACC guidelines recommend 12 months of DAPT based on observational trials. Recently, several large randomized controlled trials (RCT) suggested a noninferiority of shorter duration of DAPT and other trials showed a benefit from extended duration of DAPT after 12 months of DES implantation.

METHODS

PubMed databases were searched for RCTs comparing the continued use of DAPT to shorter duration of DAPT (aspirin alone) for variable durations beyond 3 months of DES implantation. Our analysis was limited to trials with clinical outcomes. Odds ratio (OR) and 95% confidence intervals (CI) were calculated using fixed and random-effects models. Subgroup analyses were performed for second generation DES and for trials comparing 12 months of DAPT vs. earlier interruption or longer duration of DAPT.

RESULTS

We identified 10 RCTs including 32,136 subjects randomized to continued use of DAPT vs. aspirin alone for variable durations after 3 months of DES implantation. There was no significant heterogeneity among studies (Q test P > 0.1). Compared to shorter DAPT, longer DAPT resulted in a significant reduction in stent thrombosis (0.3% vs. 0.7%, P < 0.01) and myocardial infarction (1.3% vs. 2%, P < 0.01), and a significant increase in major bleeding (0.8% vs. 0.4%, P < 0.01). There was no difference in cardiac deaths or stroke. All-cause deaths were slightly lower with shorter DAPT compared to longer DAPT (OR 0.8, 95% CI 0.7 to 0.99, P = 0.04). A small number of subjects were included between 3 and 6 months after DES implantation.

CONCLUSION

DAPT continued beyond 6 months after second generation DES implantation decreases stent thrombosis and myocardial infarction, but increases major bleeding and all-causes mortality compared to shorter DAPT (aspirin alone). There was no difference in cardiac mortality or stroke.