Direct bilirubin level is an independent risk factor for atrial fibrillation in thyrotoxic patients receiving radioactive iodine therapy.

Abstract

This study aimed to indicate the risk factors of atrial fibrillation (AF) in thyrotoxic patients receiving radioactive iodine (RAI) therapy after antithyroid drug and other medication. This study was a retrospective cohort study. Thyrotoxic patients were divided into two groups, with or without AF. Clinical features were retrospectively analyzed. Univariate and multivariate analyses of data from thyrotoxic patients were performed to evaluate the probability of AF. The following clinical factors were found to be correlated with AF: age, gender, duration of hyperthyroidism, coronary artery disease, hypertension, and levels of platelets, creatinine, uric acid (UA), and certain liver enzymes. According to the multiple logistic regression model, age and levels of UA, direct bilirubin (DBIL), and gamma-glutamyl transpeptidase (GGT) were important risk factors for predicting AF. ROC analysis showed that DBIL levels were predictive of AF, with a specificity of 0.813, a sensitivity of 0.767, and an area under the curve of 0.8515 (P < 0.001). Older age and levels of UA, DBIL, and GGT influenced the occurrence of AF in thyrotoxic patients receiving RAI. DBIL level was an important factor in predicting AF in patients with hyperthyroidism. Thus, thyrotoxic patients who have the above-mentioned risk factors should undergo routine pulse palpation should be considered for active antithyroid drug therapy.