A question of optimal DAPT duration in clinical practice

Results of the Dual Antiplatelet Therapy study, better known as DAPT, were recently presented at the American Heart Association Scientific Sessions in November. The trial addressed the key question of whether prolonging dual antiplatelet therapy (DAPT) beyond 1 year in patients treated with coronary stents is associated with a reduction in thrombotic complications. In particular, data from DAPT showed that prolonging treatment with a P2Y12 receptor inhibitor, in addition to aspirin, beyond 1 year was associated with a significant reduction in ischemic events and stent thrombosis; however, this came at the expense of an increased risk for bleeding complications.

The DAPT study has raised the dilemma on how to apply these data to everyday clinical practice, also in light of other studies that support shortening duration of DAPT because of the reduced potential for bleeding complications without any increase in thrombotic events. The latter is a practice that has been largely embraced by many, particularly in Europe, following the introduction of second-generation drug-eluting stents, which have a more favorable safety profile compared with earlier stent technologies, and recent updates in practice guidelines from the European Society of Cardiology.

Dominick J. Angiolillo

So, what am I doing in my clinical practice?

I comply with US practice guidelines and I consider at least 12 months of DAPT in my stented patients. However, I very frequently prolong treatment beyond 1 year in patients who I deem at high risk for recurrent ischemic events. In other words, I prolong treatment as a secondary prevention measure to treat the patient (and not the stent). With the results of the DAPT study, I will likely consider prolonging DAPT beyond 1 year in a broader group of my stented patients, as in the trial the benefit of prolonging therapy was consistent in many subgroups (and not just in the high-risk patients).

Overall, DAPT needs to be considered as a secondary prevention trial in which we consider prolonging DAPT in a similar way that we consider other secondary prevention therapies, such as statins.

I do believe that in the future we will be having more insights on the DAPT study about whether there were specific cohorts of patients in whom the benefits of prolonging DAPT were enhanced, as well as in whom the risk for bleeding were increased. This information will indeed be useful to better define how to best manage our patients in daily clinical practice.

In 2015, results of the PEGASUS trial, assessing the effects of prolonged treatment with ticagrelor (Brilinta, AstraZeneca) in patients with a prior MI and other enrichment factors, will provide more insights for clinicians on the role of prolonging DAPT beyond 1 year for secondary prevention of ischemic recurrences.

Nonetheless, we should not disregard studies supporting shorter duration of DAPT, particularly with second-generation DES. In my practice, I consider shortening duration of DAPT in patients at high risk for bleeding complications. I hope that, with the emerging information, we will be able better define what may be considered the minimal duration of DAPT that is mandatory to reduce risk for stent thrombosis, and differentiate this from what is a secondary prevention strategy obtained by prolonging DAPT. I indeed look forward to updates from practice guidelines to better define on how to incorporate all this new information in my daily clinical practice.

Reference:

Mauri L. N Engl J Med. 2014;371:2155-2166.

Dominick J. Angiolillo, MD, PhD, is an associate professor and the medical director of the cardiovascular research program at the College of Medicine – Jacksonville, University of Florida, and is a Cardiology Today’s Intervention Editorial Board member.

Disclosure: Angiolillo has received consulting fees/honorarium from Abbott Vascular, AstraZeneca, Bayer, Bristol-Myers Squibb, Daiichi Sankyo, Eli Lilly, Merck, PLx Pharma, Sanofi Aventis and The Medicines Company, and institutional payments for grants from AstraZeneca, Bristol-Myers Squibb, Daiichi Sankyo, Eli Lilly, GlaxoSmithKline, Sanofi-Aventis and The Medicines Company; and has participated in review activities for CeloNova, Johnson & Johnson, St. Jude Medical and Sunovion.