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Background: Evidence on the efficacy and safety of anticoagulation in preventing stroke and thromboembolic events in people with thyrotoxic atrial fibrillation is scarce. Objective: We evaluated the efficacy and safety of anticoagulation in people with thyrotoxic atrial fibrillation. Methods: Our study protocol was published in the International Prospective Register of Systematic Reviews (registration no. CRD42020222782). Four databases and two systematic review registers were searched through 25 November 2020 for interventional and observational studies comparing anticoagulation therapy with active comparators, placebo, or no treatment in people with thyrotoxic atrial fibrillation. Random-effects meta-analysis and sensitivity analysis were performed. Quality of evidence was described using the GRADE framework. Results: In the study, 23,145 records were retrieved. One randomized controlled trial and eight cohort studies were ultimately included. Effect estimates on the efficacy and safety of anticoagulation were extracted. Meta-analysis using the inverse variance and random-effects methods was conducted on four cohort studies with 3443 participants and 277 events. Anticoagulation in people with thyrotoxic atrial fibrillation reduced the risk of ischemic stroke and systemic thromboembolism by 3% (95% CI: 1-6%). Warfarin may prevent ischemic stroke in people with thyrotoxic atrial fibrillation if the CHA2DS2-VASc score exceeds 1 and when atrial fibrillation persists beyond 7 days. Direct oral anticoagulants may be associated with fewer bleeding events than warfarin. Conclusions: Anticoagulation prevents ischemic stroke and systemic thromboembolism in people with thyrotoxic atrial fibrillation. Direct oral anticoagulants may be associated with fewer bleeding events.
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INTRODUCTION: Childhood radiation exposure is a known risk factor for thyroid malignancy and dysfunction. However, local data are limited and there is no consensus on the modality and frequency of screening in this high-risk group. METHODS: Retrospective analysis study evaluating patients with childhood radiation exposure in 2006-2016 and minimum of 1-year follow-up. RESULTS: Of the 132 childhood cancer survivors in the study, thyroid malignancy was detected in 2 cases (1.5%) and thyroid nodules in 13 (9.8%). The earliest thyroid malignancy was detected 5 years post-radiotherapy via ultrasound. Of the 84 patients who had screening thyroid function test, 26 (31.0%) were detected with abnormal test results post-radiation, majority being subclinical hypothyroidism. CONCLUSION: Regular screening via clinical examination for thyroid nodules should be performed at least annually. Where feasible and if resources permit, consideration should be given to using ultrasound for thyroid nodule(s) and malignancy screening at 5 years post-radiation therapy. Screening for thyroid dysfunction can be considered from 6-12 months post-radiotherapy.