ABC | Volume 113, Nº1, July 2019

Statement Statement on Antiplatelet Agents and Anticoagulants in Cardiology – 2019 Arq Bras Cardiol. 2019; 113(1):111-134 7. Antithrombotic Therapy in Oncology Patients with Thrombocytopenia 7.1. Introduction Cardiovascular diseases and cancer are the main causes of death in Brazil. 151 Advances in treatment of neoplasm have increased survival in this population which has thus gone on to be more exposed to traditional risk factors for developing atherosclerotic disease. On the other hand, oncology patients, as they are in a pro-inflammatory and pro-thrombotic state, may develop atherosclerosis more quickly, and they have a higher risk of developing ACS. 152 Neoplasia treatment with radiotherapy and chemotherapy itself has deleterious collateral coronary effects, such as the occurrence of vasospasms and endothelial injuries. 153 Finally, the presence of thrombocytopenia increases the risk of both bleeding and ischemic phenomena. A retrospective evaluation at the MD Anderson Hospital showed that 39% of patients with ACS had platelet counts of < 100,000 cells/mm 3 . 154 7.2. Antithrombotic Therapy There are no randomized studies on antithrombotic therapy in patients with thrombocytopenia, as this population is normally excluded from large clinical trials. A retrospective study of 70 oncology patients with ACS showed lower 7-day mortality in patients with thrombocytopenia who received ASA. 155 In a case series which evaluated patients with platelet counts > 50,000 cells/mm 3 who underwent angioplasty, the use of antiplatelet agents and anticoagulants did not increase the incidence of bleeding events. 156 On the other hand, in patients with platelet counts between 30,000 and 50,000 cells/mm 3 , the use of ASA and clopidogrel was safe; lower doses of unfractionated heparin (30 IU/kg to 50 IU/kg), however, were enough to reach the therapeutic goal in this population.156 In patients with platelet counts below 10,000, risks and benefits should be evaluated individually. Platelet transfusion and antiplatelet therapy are a therapeutic possibility (Table 14). 156 There are no studies on new antiplatelet agents or non- vitamin K dependent anticoagulants in this population. Table 14 – Recommendations for use of antiplatelet agents and anticoagulants in oncology patients with thrombocytopenia Indications Grade of recommendation Level of evidence Use of acetylsalicylic acid in patients with coronary disease I A Combined use of clopidogrel and acetylsalicylic acid in patients with high-risk acute coronary syndrome or after coronary angioplasty I A Acetylsalicylic acid should always be used at a minimum dose, preferably ≤ 100 mg daily IIa C Use of antiplatelet therapy and/or anticoagulant in acute coronary syndrome patients, even if they have thrombocytopenia IIa C Use of a reduced dose of enoxaparin and unfractionated heparin in patients with platelet count < 50,000. Monitoring of therapeutic goal IIa C 1. Sorensen R, Hansen ML, Abildstrom SZ, Hvelplund A, Andersson C, Jorgensen C, et al. Risk of bleeding in patients with acute myocardial infarction treatedwith different combinations of aspirin, clopidogrel, and vitamin K antagonists in Denmark: a retrospective analysis of nationwide registry data. Lancet. 2009;374(9706):1967-74. 2. HansenML,SorensenR,ClausenMT,Fog-PetersenML,Raunso J,Gadsboll N, et al. Risk of bleeding with single, dual, or triple therapy with warfarin, aspirin, and clopidogrel in patients with atrial fibrillation. Arch InternMed. 2010;170(16):1433-41. 3. Dans AL, Connolly SJ, Wallentin L, Yang S, Nakamya J, BrueckmannM, et al. Concomitant use of antiplatelet therapy with dabigatran or warfarin in the Randomized Evaluation of Long-TermAnticoagulation Therapy (RE-LY) trial. Circulation. 2013;127(5):634-40. 4. Oldgren J, Budaj A, Granger CB, Khder Y, Roberts J, Siegbahn A, et al; RE- DEEM Investigators.Dabigatranvs.placebo inpatientswithacutecoronary syndromes on dual antiplatelet therapy: a randomized, double-blind, phase II trial. Eur Heart J. 2011;32(22):2781-9. 5. Barnes GD, Gu X, Haymart B, Kline-Rogers E, Almany S, Kozlowski J, et al. The predictive ability of the CHADS2 and CHA2DS2-VASc scores for bleeding risk in atrial fibrillation: the MAQI (2) experience. Thromb Res. 2014;134(2):294-9. 6. Roldan V, Marin F, Manzano-Fernandez S, Gallego P, Vilchez JA, Valdes M, et al. The HAS-BLED score has better prediction accuracy for major bleeding than CHADS2 or CHA2DS2-VASc scores in anticoagulated patients with atrial fibrillation. J AmColl Cardiol. 2013;62(23):2199-204. 7. Valgimigli M, Bueno H, Byrne RA, Collet JP, Costa F, Jeppsson A, et al; ESC ScientificDocumentGroup.2017ESC focusedupdateondualantiplatelet therapy in coronary artery disease developed in collaborationwith EACTS: The Task Force for dual antiplatelet therapy in coronary artery disease of the European Society of Cardiology (ESC) and of the European Association for Cardio-Thoracic Surgery (EACTS). Eur Heart J. 2018;53(1):34-78. 8. 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