Prolonged use of dual antiplatelet therapy (DAPT) following PCI may be associated with reduced benefits and greater harms in “real-world” clinical practice vs. the DAPT Study, according to a study published Nov. 8 in Circulation and presented at AHA 2021.

Neel M. Butala, MD, MBA, et al., used data from ACC’s CathPCI Registry to look at the applicability of the DAPT Study to contemporary practice. The researchers looked at differences between the DAPT study population and the contemporary PCI population in the U.S. and treatment effects of extended-duration DAPT of 30 months vs. 12 months after coronary stent procedures in a contemporary patient cohort. After linking DAPT and registry data, the researchers reweighted the DAPT population to represent the registry population and account for patient and procedural characteristics.

The study included 8,864 patients from the DAPT study and 568,540 registry patients. Compared with the DAPT population, the registry population had more comorbidities, were more likely to present with myocardial infarction (MI) and to receive a second-generation drug-eluting stent. Longer-duration P2Y12 inhibitor therapy in the DAPT cohort was associated with a 1.01% decrease in stent thrombosis, 1.9% decrease in major adverse cardiac and cerebrovascular events and a 2.27 decrease in MI but a 0.89% increase in moderate or severe bleeding.

After reweighting the DAPT cohort, prolonged DAPT use was no longer associated with a reduction in stent thrombosis, major adverse cardiac and cerebrovascular events, or MI, but increased bleeding continued.

The findings suggest that “longer duration DAPT may have more limited benefits and greater harms when applied broadly in a contemporary real-world population,” the authors write, adding that the results “highlight the need to evaluate the applicability of cardiovascular clinical trials to contemporary real-world populations more broadly.”

“As cardiovascular practice guidelines are updated, future studies can use the methods in this study to quantify differences between trial and registry populations to understand whether the average treatment effects of completed clinical trials would be applicable to contemporary populations,” they conclude.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention

Keywords: National Cardiovascular Data Registries, CathPCI Registry, Registries, Hemorrhage, Stents, Myocardial Infarction, Thrombosis, Percutaneous Coronary Intervention, Drug-Eluting Stents, Platelet Aggregation Inhibitors, AHA21, AHA Annual Scientific Sessions

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