ABC | Volume 113, Nº1, July 2019

Statement Statement on Antiplatelet Agents and Anticoagulants in Cardiology – 2019 Arq Bras Cardiol. 2019; 113(1):111-134 rivaroxaban were safer and that they reduced bleeding rates in comparison with conventional triple therapy. 18 Similarly, in 2017, the Evaluation of Dual Therapy with Dabigatran vs. Triple Therapy with Warfarin in Patients with AF that Undergo a PCI with Stenting (REDUAL-PCI) multicenter randomized prospective study included 2,725 patients with AF who underwent PCI, divided into triple therapy (warfarin + clopidogrel/ticagrelor + ASA) versus dabigatran + clopidogrel/ticagrelor. The primary outcome was major or clinically relevant bleeding. Furthermore, they tested the noninferiority of dual therapy in relation to thromboembolic events, death, and revascularization. The bleeding rate was 15.4% in the group that received 110 mg of dabigratan compared to 26.9% in the triple therapy group (p < 0.001 for noninferiority). In patients who received 150 mg of dabigratan, the bleeding rate was 20.2% compared to 25.7% in the triple therapy group (p < 0.001 for noninferiority). The combined events rates were 13.7% and 13.4% in the double and triple therapy groups, respectively (p = 0.005 for noninferiority). They mainly observed a reduced need for revascularization. The use of dual therapy with dabigatran was thus shown to be noninferior to triple therapy. As in the PIONEER AF-PCI study, the REDUAL-PCI study was not powered to show differences in coronary events or death. It was only possible to evaluate safety. 19 Triple therapy should, thus, be considered only for patients with low hemorrhage risks during the shortest time possible (preferably 1 month, with the possibility of extending up to 6 months). After this period, anticoagulant use combined with just 1 antiplatelet agent should be maintained. However, when there is a high ischemia risk (Table 3) as well as a high hemorrhage risk, the recommendation is to use triple therapy for, at most, 1 month or to initiate dual therapy with an anticoagulant and clopidogrel directly (Table 4 and Figure 1). On the other hand, in patients with high risks of bleeding and low ischemia risks, in accordance with the results of the main published studies, the current recommendation is to initiate dual therapy with an anticoagulant and clopidogrel from the beginning (Table 4 and Figure 1). It is, preferably, recommended to use NOAC instead of warfarin, due to the predictability of their effect. Furthermore, the NOAC should be chosen in accordance with the medical knowledge already established in this context and at doses previously studied in scientific research. When opting to use warfarin, the INR should be maintained close to 2.0. Suspension of the antiplatelet agent is recommended 12 months after the last coronary event. Evidence for this conduct is scarce; it is, however, based on studies that showed that, after 1 year, anticoagulation is superior to ASA and that the combination, in addition to increasing bleeding rate, has no additional benefits. 20 Combined therapy with clopidogrel and OAC may be prolonged for more than 1 year in patients with high ischemia risk and mechanical valve prostheses. 3. Duration of Dual Antiplatelet Therapy Following Percutaneous Coronary Intervention 3.1. Introduction The combination of P2Y 12 inhibitors with ASA monotherapy is known to be a great ally in the management of patients with coronary artery disease (CAD), be it acute or stable, and it reduces the risk of atherothrombotic phenomena, as well as stent thrombosis rates following PCI. 21-23 This reduced ischemia risk is, however, indisputably associated with higher bleeding rates. 22-25 The state of the art is to weigh the risks and benefits of dual therapy, as well as treatment duration, by contemplating clinical characteristics, the anatomical characteristics of the lesions addressed, and the type of stent used. The risk of stent thrombosis in patients who have undergone PCI with conventional (metallic) stents is much more frequent during the first days and weeks following the procedure. In this manner, dual antiplatelet therapy is recommended for 1 month. 26 With the advent of drug-eluting stents, conventional stents have been reserved, ideally, for patients with very high risks of bleeding who need shorter periods (at least 1 month) of dual antiplatelet therapy. In Brazil, however, conventional metallic stents continue to be used, especially in public health services. Thrombosis in first-generation drug-eluting stents intensified perspectives on therapy duration in the past. 27 Although the relative risk is still considerable, late or very late Table 3 – Definition of high long-term ischemic risk Prior history of stent thrombosis during adequate antiplatelet therapy “Final” artery angioplasty Multiarterial coronary disease, especially in patients with diabetes Chronic renal insufficiency (ClCr < 60 mL/min) At least 3 stents and/or 3 lesions treated PCI in bifurcation, with at least 2 stents placed Total stent length > 60 mm Treatment for chronic coronary occlusion CrCl: creatinine clearance. 116