ABC | Volume 113, Nº1, July 2019

Statement Statement on Antiplatelet Agents and Anticoagulants in Cardiology – 2019 Arq Bras Cardiol. 2019; 113(1):111-134 anticoagulants. There were no significant differences in the primary outcome, which was a composite of transient ischemic attack, stroke, peripheral embolism, AMI, and cardiovascular death (0.51% versus 1.02%; risk ratio [RR] 0.5; 95% CI 0.15 to 1.73), or the safety outcome, which was major bleeding (0.6% versus 0.8%; RR 0.76; 95% CI 0.21 to 2.67). Time to cardioversion was shorter in the rivaroxaban group. 79 Furthermore, post hoc analysis of the ROCKET-AF study also showed no difference in events between patients who underwent cardioversion using rivaroxaban or warfarin (HR 1.38; 95% CI 0.61 to 3.11). 100 With relation to dabigatran, which is a direct thrombin inhibitor, post-hoc analysis of the RE-LY study observed that 1,983 cardioversions were performed with 1,270 patients (from the total of more than 18,000 patients randomized in the original study). The incidence of stroke or systemic embolism in up to 30 days after cardioversion was similar between the groups receiving pericardioversion anticoagulation with warfarin, dabigatran 110 mg twice daily, and dabigatran 150 mg twice daily (0.6%, 0.8%, and 0.3%, respectively; p > 0.05). In the same manner, there were no differences in bleeding rates between the groups (0.6%, 1.7%, and 0.6%, respectively; p > 0.05). The results were not altered by prior TEE.77 Moreover, an observational Danish study, which compared 456 patients with nonvalvular AF receiving dabigatran with 774 patients receiving warfarin, provided evidence that there was a reduced median time to first cardioversion (4.0 weeks, with interquartile interval [IQI] of 2.9 to 6.5 compared to 6.9 weeks, with IQI of 3.9 to 12.1, for dabigatran and warfarin, respectively). No differences were observed between the 2 drugs regarding efficacy and safety. 101 With relation to apixaban, post-hoc analysis of the ARISTOTLE study compared patients who underwent cardioversion receiving apixaban or warfarin. A total of 743 cardioversions occurred in 540 patients, with 265 patients in the apixaban group and 275 in the warfarin group. Average age (67 years old) and LVEF (around 52%) were similar in both groups, and average CHADS 2 score in the apixaban group was 1.8 (± 1.0) and 1.9 (± 1.1; p = 0.17) in the warfarin group. There were no (zero) strokes or embolic events over 30 days in either of the groups, and 1 major bleeding episode occurred in each group. 78 These data were subsequently confirmed in the EMANATE trial, which was presented at the European Congress of Cardiology in 2017 (to be published). In this study, 1,500 patients were randomized to receive apixaban or heparin/warfarin (conventional treatment) within 48 hours after cardioversion. Average age in both groups was approximately 64, and average CHA 2 DS 2 -VASc scores were Table 11 – Recommendations on cardioversion anticoagulation in atrial fibrillation Indications Grade of recommendation Level of evidence Electrical cardioversion is recommended for patients with hemodynamic instability to reestablish cardiac output I B Anticoagulation with heparin or a new oral anticoagulant should be initiated as soon as possible before any cardioversion for AF or flutter IIa B In stable patients, with persistent AF, who are to undergo electrical or chemical cardioversion, OAC is recommended for at least 3 weeks before and 4 weeks after cardioversion within the therapeutic range (INR between 2 and 3). After 4 weeks, OAC maintenance should be in accordance with CHA 2 DS 2 VASc risk score I B TEE is recommended to exclude thrombi as an alternative to periprocedural anticoagulation when early cardioversion is programmed I B In the event that a thrombus is identified, anticoagulation should be maintained for 3 weeks I C It is recommended to repeat TEE after 3 weeks of anticoagulation to ensure that the thrombus has been resolved before cardioversion IIa C During the pericardioversion period, it is possible to opt for OAC with vitamin K antagonists or new anticoagulants, for the previously described duration IIa B The use of OAC is indicated for patients with atrial flutter, with the same considerations as in AF I C The preferred dose of rivaroxaban should be 20 mg daily, as long as there is a low risk of bleeding I B The preferred dose of dabigatran should be 150 mg twice daily, as long as there is a low risk of bleeding I B The preferred dose of apixaban should be 5 mg twice daily, as long as there is a low risk of bleeding I B For patients undergoing electrical cardioversion guided by TEE without thrombi, UFH is recommended EV (bolus following by continuous infusion) before cardioversion and should be maintained until full OAC is reached I B For patients with AF who need emergency electrical cardioversion, UFH is recommended EV (bolus following by continuous infusion) I C For patients undergoing electrical cardioversion guided by TEE without thrombi, LMWH is recommended before cardioversion and should be maintained until full OAC is reached I B For patients with AF who need emergency electrical cardioversion, a full dose of LMWH is recommended I C AF: atrial fibrillation; EV: endovenous; INR: international normalized ratio; LMWH: low-molecular weight heparin; OAC: oral anticoagulation; TEE: transesophageal echocardiography; UFH: unfractionated heparin. 123