Optimal Duration of Dual Antiplatelet Therapy After DES Implantation | Journal Scan

Study Questions:

What are the mortality and other clinical outcomes with different dual antiplatelet therapy (DAPT) strategies?


The investigators searched Medline, Embase, Cochrane databases, and proceedings of international meetings on November 20, 2014, for randomized controlled trials comparing different DAPT durations after drug-eluting stent (DES) implantation. They extracted study design, inclusion and exclusion criteria, sample characteristics, and clinical outcomes. DAPT duration was categorized in each study as shorter versus longer, and as 6 months or shorter versus 1 year versus longer than 1 year. Analyses were done by both frequentist and Bayesian approaches. The primary endpoint was all-cause mortality. The pooled hazard ratio (HR) was calculated with both fixed-effect (inverse variance weighted) and random-effect (DerSimonian and Laird) models.


The authors identified 10 trials published between December 16, 2011, and November 16, 2014, including 31,666 randomly assigned patients. By frequentist pairwise meta-analysis, shorter DAPT was associated with significantly lower all-cause mortality compared with longer DAPT (HR, 0.82; 95% CI, 0.69–0.98; p = 0.02; number needed to treat [NNT] = 325), with no significant heterogeneity apparent across trials. The reduced mortality with shorter compared with longer DAPT was attributable to lower noncardiac mortality (0.67, 0.51–0.89; p = 0.006; NNT = 347), with similar cardiac mortality (0.93, 0.73–1.17; p = 0.52). Shorter DAPT was also associated with a lower risk of major bleeding, but a higher risk of myocardial infarction and stent thrombosis. The investigators noted similar results in a Bayesian framework with noninformative priors. By network meta-analysis, patients treated with 6-month or shorter DAPT and 1-year DAPT had higher risk of myocardial infarction and stent thrombosis, but lower risk of mortality compared with patients treated with DAPT for longer than 1 year. Patients treated with DAPT for 6 months or shorter had similar rates of mortality, myocardial infarction, and stent thrombosis, but lower rates of major bleeding than did patients treated with 1-year DAPT.


The authors concluded that although treatment with DAPT beyond 1 year after DES implantation reduces myocardial infarction and stent thrombosis, it is associated with increased mortality.


The primary finding of this study is that shorter DAPT duration was associated with significantly lower rates of all-cause mortality compared with longer DAPT due to an increased risk of noncardiovascular mortality with longer-duration DAPT not offset by a reduction in cardiac mortality. Furthermore, compared with longer DAPT, shorter DAPT was associated with significantly lower rates of major bleeding and any bleeding, but with increased rates of myocardial infarction and definite or probable stent thrombosis. The totality of the available data suggests an individualized approach for DAPT duration, where the specific risks versus benefits are carefully considered taking into account clinical presentation, type of stent, bleeding risk, and stent thrombosis risk, instead of recommending the same duration for every individual undergoing DES implantation.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention

Keywords: Drug-Eluting Stents, Stents, Mortality, Platelet Aggregation Inhibitors, Risk, Myocardial Infarction, Thrombosis, Meta-Analysis

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