History of major bleeding predicts risk of clinical outcome of patients with atrial fibrillation: results from the COOL-AF registry

Objective To compare clinical outcomes between patients with and without history of major bleeding according to types of antithrombotic medications in patients with non-valvular atrial fibrillation(NVAF). Methods We conducted a multicenter registry of patients with NVAF during 2014 to 2017 in Thailand. The following data were collected: demographic data, type of NVAF, medical illness, components of CHA2DS2-VASc and HAS-BLED scores, history of bleeding and severity, investigations, and antithrombotic medications. Clinical outcomes were death, bleeding, and ischemic stroke/transient ischemic attack(TIA). Results There were a total of 3218 patients. The average age was 67.3 ± 11.3 years, and 58.3% were men. Sixty-nine patients(2.14%) had a history of major bleeding. Antithrombotic use was, as follows: 2126 patients(75.3%) received oral anticoagulant(OAC) alone, 555(17.2%) received antiplatelet alone, 298(9.3%) received both, and 239(7.4%) received neither. During follow-up, 9.9% had major adverse outcomes, including death(5.9%), ischemic stroke/TIA(2.5%), and major bleeding(4.0%). There were no significant differences in the types of antithrombotic medications between patients with and without history of major bleeding. Multivariate analysis revealed old age, low body mass index, hypertension, diabetes, heart failure, and history of major bleeding to be independently associated with major adverse outcome. Adverse events significantly increased in patients with OAC plus antiplatelet. Conclusions History of major bleeding was identified as a factor that significantly affects clinical outcome. Inappropriate use of OAC plus antiplatelet should be avoided. Special caution should be made in this high-risk patients.