A study presented at the AHA Scientific Sessions looks at the risks and benefits of continuing dual antiplatelet therapy beyond one year after placement of one or more drug-eluting stents as compared with aspirin therapy alone.
The “Twelve or 30 months of dual antiplatelet therapy after drug-eluting stents (DAPT),” study’s authors conclude that, while continuing dual antiplatelet therapy with a thienopyridine (clopidogrel or prasugrel) in addition to aspirin after one year significantly reduced the risks of stent thrombosis and major adverse cardiovascular and cerebrovascular events, continuation was also associated with increased risk of bleeding.
Given the currently available scientific evidence on antiplatelet therapy, the Society for Cardiovascular Angiography and Interventions (SCAI) recommends the interventional cardiology community should continue to follow the practice guidelines of one year (12 months) of dual antiplatelet therapy. However, the DAPT findings suggest that, in specific patient cohorts, a longer duration of the therapy may be considered. These data contrast with other smaller randomised trials, suggesting that shorter durations of dual antiplatelet therapy may be considered, particularly with the use of second generation drug-eluting stents. Thus, each physician should use his or her judgment in tailoring therapy to the individual patient.
The DAPT study found that continuing dual antiplatelet treatment after one year significantly reduced the rates of stent thrombosis (0.4% versus 1.4%) and major adverse cardiovascular and cerebrovascular events (4.3% versus 5.9%). There was also a significant reduction in myocardial infarction (2.1% versus 4.1%), including myocardial infarction not related to stent thrombosis. Although there was a modest increase in overall mortality among the patients on extended dual antiplatelet therapy, this increase may have been at least partly due to an imbalance in pre-existing cancer in that group. The overall benefit of prolonging dual antiplatelet therapy occurred at the expense of increased moderate or severe bleeding.
This study adds to the body of scientific literature regarding the question of how long to continue dual antiplatelet therapy after the placement of a drug-eluting stent. The study reinforces the importance of dual antiplatelet therapy, which the current clinical guidelines for percutaneous coronary intervention state should be continued for one year after placement of a drug-eluting stent, and indicates extending the therapy may be considered in some patients.
“While interventional cardiologists may tailor how long antiplatelet therapy is continued based on physician clinical judgment and the individual patient’s needs and treatment goals, the guideline recommendation of one year of dual antiplatelet therapy remains steadfast,” said Dominick J Angiolillo, associate professor of medicine and director of cardiovascular research at the University of Florida College of Medicine.
“DAPT is one of many studies that address the issue of how long to continue dual antiplatelet therapy after placement of a drug-eluting stent,” said Angiolillo. “We cannot ignore other trials presented [at the AHA Scientific Sessions] or earlier trials suggesting shorter durations of dual antiplatelet therapy for some patients. We will continue to follow guideline-based care, while evaluating the findings of DAPT and the forthcoming PEGASUS trial and how best to implement the implications of those results in clinical practice for the benefit of each individual patient.”