Dual antiplatelet therapy (DAPT) combining aspirin with an adenosine diphosphate receptor inhibitor has significantly reduced the incidence of ischaemic events, including stent thrombosis, after percutaneous coronary intervention, and is thus strongly recommended by international practice guidelines.
However, less clear has been the optimal duration for which DAPT should be recommended, especially in the context of a drug-eluting stent (DES)
implantation, where previous reports have implicated an association with increased late stent thrombosis events after DAPT has been stopped. In addition, this issue is further influenced by the exposure of the patient to an increased risk of bleeding while on DAPT.
The DAPT study was therefore designed to evaluate the benefits and risks of continuing a patient on DAPT beyond 12 months after coronary stenting3. This study was distinct from prior studies in that it was powered to detect a difference in stent thrombosis rates, and was composed of five individual studies with similar protocols involving eight different devices and pharmaceutical companies. Briefly, the DAPT study was an international, multicentre, prospective, blinded, placebo-controlled study that included 9,961 patients who had successfully completed 12 months of DAPT after coronary stenting without a significant ischaemic or bleeding event, and who were then randomly assigned to either continuing on DAPT for a further 18 months, or stopping DAPT and continuing on aspirin alone4. The two co-primary efficacy endpoints were stent thrombosis and major adverse cardiovascular and cerebrovascular events (MACCE) (a composite of death, myocardial infarction, or stroke) during the period from 12 to 30 months.