It is now standard practice to give dual antiplatelet therapy (DAPT) for one year after implantation of a drug eluting stent in a coronary artery. The question of continuing has been addressed in the DAPT Study. Now the results of the DAPT Study for the diabetic subset has been published in Circulation . Around twelve thousand patients who received dual antiplatelet therapy for one year after coronary stenting and free of ischemic or bleeding complications were randomized to further 18 months of dual antiplatelet or single antiplatelet therapy. It was found that there is a further reduction in stent thrombosis and myocardial infarction by extended dual antiplatelet therapy. But the benefits were attenuated in diabetic patients. Still the benefits were better than single antiplatelet agent even in the diabetic subset. So we have now evidence for extended dual antiplatelet therapy beyond one year after coronary stenting in those without any bleeding complications.
The important reason for stepping down to single antiplatelet therapy after one year was mainly that the bleeding risk which became comparable to the benefit of prolonged dual antiplatelet therapy. Moreover, many patients who suffer fractures or have other indications for semi-urgent non-cardiac surgery had to wait for surgery during discontinuation of the second antiplatelet agent. If patient is only on aspirin, most surgeons now take up the case if the surgery is not associated with a high bleeding risk. Same is true of anaesthesiologists agreeing for neuraxial blocks.
- Meredith IT et al. Mellitus and Prevention of Late Myocardial Infarction After Coronary Stenting in the Randomized Dual Antiplatelet Therapy Study. 2016; 133: 1772-1782.