ABC | Volume 111, Nº3, September 2018

Original Article Evaluation of the Bleeding Intensity of Patients Anticoagulated with Warfarin or Dabigatran Undergoing Dental Procedures Marcus Vinicius Santos Andrade, 1,2,3 Luciana Azevedo Prata Andrade, 2,3 Alan Freitas Bispo, 3 Luana de Alencar Freitas, 3 Milena Quadros Sampaio Andrade, 1 Gilson Soares Feitosa, 1,2 Gilson Soares Feitosa-Filho 1,2 Escola Bahiana de Medicina e Saúde Pública, 1 Salvador, BA - Brazil Hospital Santa Izabel da Santa Casa de Misericórdia da Bahia, 2 Salvador, BA - Brazil Centro de Referência em Doenças Cardiovasculares - Dr. Adriano Pondé, 3 Salvador, BA - Brazil Mailing Address: Marcus Vinicius Santos Andrade • Hospital Santa Izabel - Diretoria de Ensino e Pesquisa - Praça Cons. Almeida Couto, 500. Postal Code 40050-410, Nazaré, Salvador, BA - Brazil E-mail: mvandrade@cardiol.br, marcuscardio@hotmail.com Manuscript received January 22, 2018, revised manuscript March 21, 2018, accepted April 25, 2018 DOI: 10.5935/abc.20180137 Abstract Background: Thrombotic disorders remain one of the leading causes of death in the Western world. Dabigatran appeared as an alternative to warfarin for anticoagulation in the treatment of atrial fibrillation (AF). The risk associated with bleeding due to its use has been documented in several randomized clinical trials, but no large study has examined in detail the risk of bleeding during dental extraction and other dental procedures involving bleeding. Objective: To compare the intensity of bleeding in individuals taking dabigatran or vitamin K antagonist (warfarin) and undergoing dental procedures. Methods: Prospective, single-center, controlled study with one single observer. Patients diagnosed with nonvalvular AF, on warfarin or dabigatran, cared for at a cardiology referral center, and requiring single or multiple dental extractions, were evaluated up to seven days post-extraction. The following outcomes were assessed: bleeding time between the beginning and the end of suture and complete hemostasis; bleeding before the procedure, after 24 hours, 48 hours, 7 days, during and after suture removal (late); p<0.05 was defined as of statistical relevance. Results: We evaluated 37 individuals, 25 in the warfarin group and 12 in the dabigatran group. Age, sex, weight, height, blood pressure, color, schooling, family income and comorbidities were similar between the two groups. Regarding bleeding after 24 hours of the procedure, no one in the dabigatran group had bleeding, whereas 32% in the warfarin group had documented bleeding (p = 0.028). The other variables analyzed did not differ between the groups. Conclusions: This study suggests that, regarding dental extraction, there is no statistically significant difference in the intensity of bleeding of patients taking dabigatran as compared to those taking warfarin. Bleeding 24 hours after the procedure was less frequent among patients on dabigatran. (Arq Bras Cardiol. 2018; 111(3):394-399) Keywords: Hemorrhage/complications; Anticoagulants; Oral Surgical Procedures; Bleeding Time; Warfarin; Dabigatran. Introduction Thrombotic disorders remain one of the leading causes of death in the Western world. Several treatments with anticoagulants have been used, including unfractionated heparin, low-molecular-weight heparin, fondaparinux, vitamin K antagonists (warfarin), and novel oral anticoagulants (NOACs), such as apixaban, dabigatran and rivaroxaban. 1 Warfarin, the major anticoagulant, has been used for more than five decades in the United States and worldwide. Over two million people in the United States are estimated to use warfarin, with approximately 300,000 new prescriptions every year. 2 Despite their proven efficacy, the clinical use of vitamin K antagonists has some drawbacks, such as food and drug interaction, variable anticoagulation response, slow onset of therapeutic effects, need for therapeutic responsemonitoring by use of prothrombin time (PT) and International Normalized Ratio (INR), and narrow therapeutic range. 3 Based on the drawbacks of warfarin use and the low efficiency of anticoagulation rates in clinical practice, studies assessing NOACs have been planned and conducted in recent years. The NOACs have been developed and properly assessed in phase 2 and 3 studies, which have clearly demonstrated their efficacy and safety. Some drugs are factor IIa inhibitors (thrombin inhibitor), such as dabigatran, while others are factor Xa inhibitors, such as apixaban, rivaroxaban and edoxaban. Patients with atrial fibrillation (AF) are at high risk for stroke. Although warfarin and other vitamin K antagonists are highly effective, reducing the risk of stroke in approximately two thirds of the cases, their use has the already described drawbacks. Recently, NOACs have shown to be as effective as warfarin, or even superior, in preventing stroke and systemic embolism. 4 394