Invited Lecture II
From Evidence to Practice

The “Optimal” Duration of Dual Antiplatelet Therapy Following DES Revascularization
——Live Interview with Professor David E. Kandzari

<International Circulation>: How do you determine the “optimal” duration of dual antiplatelet therapy following DES revascularization？How many factors should be involved in consideration of the duration of dual antiplatelet therapy following DES revascularization？

Dr. Kandzari: Our current recommendations in the United States and some European countries are for patients who receive a drug-eluting stent to receive aspirin indefinitely combined with at least one year of thenopyridine therapy. We must understand that the primary motivator for this is a concern for stent thrombosis， and the use of drug-eluting stents for some clinicians has been assumed to require lifelong antiplatelet therapy while other clinicians do not believe that even one year of thenopyridine treatment is required. Therefore， we have a great deal of variability in clinical practice and a great deal of uncertainty. This issue of what the optimal duration of dual antiplatelet therapy is after DES revascularization challenges every clinician who is involved in the care of a patient who is being considered for a drug-eluting stent or even patients who have already received drug-eluting stents. The only way that we can truly define the best duration of antiplatelet therapy is through the performance of clinical trials that will not only evaluate safety outcomes like bleeding but also balance that with efficacy outcomes in terms of reducing death， myocardial infarction， and stent thrombosis. Even then the story becomes very challenging when we consider that there might be differences in the risk of stent thrombosis between different types of DES and more recently there is emerging evidence suggesting that there may differences among individuals in their responses to antiplatelet therapy. To date， our recommendations for one year of antiplatelet therapy are derived largely from observation studies that have suggested that longer term durations may reduce the risk of death and M.I. but not necessarily stent thrombosis. The second motivator for our current guideline recommendations is this intuitive perception that longer term durations of dual antiplatelet therapy could reduce late stent thrombotic complications. Ultimately， we must realize that most of the current recommendations are based on more on opinion rather than clinical trial evidence. In fact， most of the observational data that we have today indicates that beyond six months， treatment with dual antiplatelet therapy may not reduce the risk of stent thrombosis and in a broad all-comers population it may not even reduce the risk of death and myocardial infarction. Just recently， one randomized trial further suggests that major adverse events， including stent thrombosis and bleeding， may not significantly differ between 12 and 24 months of dual antiplatelet therapy following DES revascularization.