Duration of dual-antiplatelet therapy may affect risk of stent complications

1. From a systematic review, longer duration dual-antiplatelet therapy was associated with a decreased risk of myocardial infarction in patients with drug-eluting stents.

2. However, longer duration therapy also increased the risk of major bleeding and all-cause mortality.

Evidence Rating Level: 1 (Excellent)

Study Rundown: Patients with coronary artery disease (CAD) who also experience acute coronary syndrome (ACS) are often treated with drug-eluting stent (DES) revascularization. After DES placement, patients are often started on a course of dual-antiplatelet therapy (DAPT), which includes aspirin and a P2Y12 inhibitor, such as clopidogrel. However, the appropriate length of time a patient should remain on DAPT remains controversial. The goal of this systematic review of nine randomized, controlled trials (RCT) was to compare longer- versus shorter-duration DAPT after DES placement. The primary outcomes assessed were all-cause mortality, myocardial infarctions (MIs), and major bleeding events. The longer-duration DAPT resulted in 8 fewer MIs per 1000 patients per year. However, longer-duration DAPT was also associated with 6 more major bleeding events per 1000 patients per year. Additionally, there was a slight increase in all-cause mortality in the longer-duration DAPT cohort. The major limitations of this study include a high degree of imprecision in several included trials and potential bias due to lack of blinding in most of the trials. Overall, this analysis demonstrates that longer-duration DAPT may result in increased risk of complications and was associated with an increased mortality when compared to shorter-duration DAPT.

Click to read the study, published today in the Annals of Internal Medicine

Relevant Reading: Twelve or 30 months of dual antiplatelet therapy after drug-eluting stents

In-Depth [systematic review]: The authors searched MEDLINE and EMBASE for RCTs that compared longer- and shorter-duration DAPT in patients receiving DES. Nine of the 18 articles selected met the following inclusion criteria: the shorter-duration treatment group received DAPT for at least 3 months, the longer-duration treatment group received DAPT for at least 6 months longer than patients in the shorter-duration group; and at least one of the following outcomes were assessed: all-cause death, cardiovascular death, MI, major bleeding, recurrent revascularization, or any stroke. Analysis of the pooled data showed a lower risk of MI in the longer-duration DAPT group (RR 0.73; CI 0.58-0.92). There was also a higher risk of a major bleeding event in the longer-duration group (RR 1.63; CI, 1.34-1.99). Lastly, there was a slightly higher risk of all-cause mortality in the longer-duration group (RR 1.19; CI 1.04-1.36). There were no differences in risk for cardiovascular mortality, recurrent revascularization or any stroke between the two groups.

Image: PD

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