NOACs versus warfarin in people with atrial fibrillation and thyroid dysfunction

Anticoagulant therapy is an important measure to prevent stroke or other embolic events in patients with atrial fibrillation (AF). Warfarin, a classical anticoagulant, has a narrow therapeutic range and requires frequent testing and adjustment, making it inconvenient for patients. Additionally, thyroid dysfunction affects the coagulation–fibrinolysis imbalance, with hyperthyroidism increasing the risk of thrombosis and hypothyroidism increasing the risk of bleeding. The study aimed to evaluate the safety and effectiveness of non-vitamin K antagonist oral anticoagulants (NOACs) compared to warfarin in thyroid dysfunction patients. This retrospective study was conducted at 2 academic medical centers in southwestern China, including patients at least 18 years of age with abnormal thyroid function who were initiated on NOACs or warfarin for AF. The primary endpoint was the composite of clinical failure, including mortality, stroke incidence, and major bleeding events. We compared the baseline characteristics and the complex endpoint between NOACs group and warfarin group. A total of 137 patients, 86 receiving NOACs and 51 receiving warfarin were included in the final analysis. At the baseline, the prevalence of chronic heart failure was more common in those receiving warfarin (79.6% vs 55.3%, P = .005), who also had higher CHA2DS2-VASc scores (89.8% vs 74.12% in male ≥ 2 or female ≥ 3, P = .029). It is found that NOACs had a significantly higher estimated 3-year complex endpoint survival rate compared to warfarin. Stratified analyses show that patients with a body mass index < 24 kg/m2 being at a higher risk of experiencing endpoint events. NOACs appear to be superior to warfarin in long-term survival rate for patients with AF and thyroid dysfunction, especially in those with body mass index < 24 kg/m2.