Dual antiplatelet therapy (DAPT) is the cornerstone of pharmacological treat­ment aimed at preventing the atherothrombotic complications in patients with several coronary artery disease (CAD) manifestations. Physicians face several challenges while prescribing DAPT that include selecting the appropriate P2Y12 inhibitor and determining the optimal duration of DAPT while minimizing the risk of ischemic and bleeding complications in light of each patient’s clinical characteristic and circumstance.

The ACC/AHA guidelines recommend that for patients with ACS treated with DAPT following BMS or DES implantation, P2Y12 inhibitor therapy (clopidogrel, prasugrel, or ticagrelor) should be given for at least 12 months. In patients treated with DAPT, a daily aspirin dose of 81 mg (range, 75 mg to 150 mg) is recommended. The guideline further recommends that in patients treated with DAPT after coronary stent implantation who subsequently undergo CABG, P2Y12 inhibitor therapy should be resumed postoperatively so that DAPT continues until the recommended duration of therapy is completed. In patients with ACS (NSTE-ACS or STEMI) being treated with DAPT who undergo CABG, P2Y12 inhibitor therapy should be resumed after CABG to complete 12 months of DAPT therapy after ACS. Additionally, in patients with ACS managed with medical therapy alone (without revascularization or fibrinolytic therapy) and treated with DAPT, P2Y12 inhibitor therapy (clopidogrel or ticagrelor) should be continued for at least 12 months.

According to the ESC guidelines, for stable CAD patients treated with PCI, the duration of DAPT is 1-6 months depending on the bleeding risk. For patients in whom the ischemic risk prevails over the risk of bleeding, a longer DAPT duration may be considered. For ACS patients irrespective of the final revascularization strategy (medical therapy, PCI, or CABG), the default DAPT duration is 12 months. Six-month therapy duration should be considered in high bleeding risk patients, while >12-month therapy may be considered in ACS patients who have tolerated DAPT with a low bleeding risk. Clopidogrel is considered the default P2Y12 inhibitor in patients with stable CAD treated with PCI, those with an indication for concomitant oral anticoagulation, as well as in ACS patients in whom ticagrelor or prasugrel are contraindicated. Some studies have found no increased risk of stent thrombosis with shorter-duration DAPT (3-6 months). A shorter duration of DAPT results in fewer bleeding complications. Shorter-duration DAPT may be most reasonable in patients currently being treated with “newer-generation” (eg, everolimus-eluting) DES, which are associated with lower stent thrombosis and MI rates than those of “first-generation” DES.

In line with this, the STOPDAPT trial assessed the outcome with 3-month DAPT duration after CoCr-EES implantation. The event rates beyond 3 months were very low (cardiovascular death: 0.5%, MI: 0.1%, ST: 0%, stroke: 0.7%, and TIMI major/minor bleeding: 0.8%). Cumulative 1-year incidence of the primary endpoint (composite of cardiovascular death, MI, stroke, definite stent thrombosis (ST) and TIMI major/minor bleeding) was 2.8%, which was lower than the pre-defined performance goal of 6.6%. Using the CoCr-EES group in the RESET trial as a historical comparison group, where about 90% of patients had continued DAPT at 1 year, cumulative incidence of the primary endpoint tended to be lower in the STOPDAPT than in the RESET (2.8% versus 4.0%) and adjusted hazard ratio was 0.64. The cumulative incidence of definite/probable ST was lower in the STOPDAPT than in the RESET [0 patient (0%) versus 5 patients (0.3%)]. The study concluded that stopping DAPT at 3 months in selected patients after CoCr-EES implantation was at least as safe as the prolonged DAPT regimen adopted in the historical control group.

Decisions about the timing of surgery and whether to discontinue DAPT after coronary stent implantation must be individualized. Such decisions involve weighing the particular surgical procedure and the risks of delaying the procedure, the risks of ischemia and stent thrombosis, and the risk and consequences of bleeding.