Duration of Dual Anti-Platelet Therapy Post-Percutaneous Intervention: Is There A Correct Amount of Time?

Dual antiplatelet therapy (DAPT) is effective in preventing in-stent thrombosis (IST) after placement of drug-eluting coronary stents (DES) and in attenuating risk of athero-thrombotic events, primarily myocardial infarction, among patients with advanced coronary atherosclerosis. However, all studies of DAPT demonstrate an increased risk of moderate or severe bleeding for the duration of therapy. The extent of benefit and risk with various periods of DAPT after DES placement has been evaluated in multiple observational studies and randomized clinical trials. Most studies indicate little or no important reduction of ischemic events but significant increases in bleeding with prolonged treatment. The Dual Antiplatelet Therapy Study was the only randomized trial sufficiently powered to assess IST as an individual endpoint, and this study found that continuing DAPT from 12 to 30months after DES placement provided important reductions in IST and a composite of adverse ischemic events. When all data are considered, a cogent argument can be made for using just 3 to 6months DAPT in patients treated with contemporary second generation DES when the goal of treatment is to avoid IST. Longer therapy should be recommended for patients treated with first generation DESs, for whom a persisting signal of IST risk is apparent, and for patients with low risk for bleeding who wish to minimize their risk of athero-thrombotic events, both related and unrelated to DES.