Effects of Nonadherence to Dual Antiplatelet Therapy | Journal Scan

Study Questions:

What is the frequency and clinical impact of dual antiplatelet therapy (DAPT) nonadherence?

Methods:

The EDUCATE (Endeavor Drug-Eluting Stenting: Understanding Care, Antiplatelet Agents and Thrombotic Events) registry is a prospective registry to assess practice patterns and patient adherence to DAPT and the risk of subsequent thrombotic events. After successful Endeavor zotarolimus-eluting stent implantation, 2,265 patients were enrolled in this registry with limited exclusions and monitored during 12 months of prescribed DAPT. Predictors of any nonadherence (ANA) at 6 months were analyzed by multivariable analysis, and the association between ANA at 6 or 12 months with the endpoints of death, myocardial infarction (MI), and stent thrombosis was assessed.

Results:

The study population included 30% female patients, 34% with diabetes, and 36% with acute coronary syndromes. ANA occurred in 208 patients (9.6%) before 6 months and 378 patients (18.5%) before 1 year. Major bleeding (odds ratio [OR], 12.83; 95% confidence interval [CI], 7.55-21.80; p < 0.001) was the only predictor of ANA at 6 months. In time-dependent analyses, ANA before 6 months was associated with an increased risk of death or MI (7.6% vs. 3.0%; p < 0.001) and a numerical increase in stent thrombosis (2.0% vs. 0.9%; p = 0.12). After adjustment for baseline differences, ANA within 6 months remained associated with death or MI (OR, 1.95; 95% CI, 1.02-3.75). ANA occurring after 6 months did not increase the risk of subsequent ischemic events.

Conclusions:

The authors concluded that DAPT nonadherence occurs frequently and is associated with increased risk for thrombotic complications if it occurs within the first 6 months.

Perspective:

This multicenter international registry of patients undergoing stenting with the E-ZES reports that nonadherence with the prescribed 12 months of DAPT was frequent, including prolonged (>14 days) nonadherence in over 5% of patients within 6 months of DES implantation. Nonadherence in the first 6 months correlated strongly with the occurrence of major bleeding and was independently associated with adverse thrombotic outcomes at 1 year. For patients fully compliant with DAPT during the first 6 months after E-ZES implantation, subsequent nonadherence between 6 and 12 months did not confer increased ischemic risk. While the optimal duration of DAPT after newer-generation DES remains a matter of debate, uninterrupted DAPT therapy of at least 6 months and preferably 12 months is indicated for most patients undergoing percutaneous coronary intervention.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention

Keywords: Drug-Eluting Stents, Stents, Percutaneous Coronary Intervention, Platelet Aggregation Inhibitors, Thrombosis, Myocardial Infarction, Prospective Studies, Registries, Patient Compliance, Risk


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