SUN-383 Thromboembolism In Patients With Atrial Fibrillation Due To Hyperthyroidism-a Systematic Review And Meta-analysis

Abstract Disclosure: A. Khan: None. A. Aziz: None. H. Ahmed Elamin: None. J. Khan: None. M. Sadiq: None. F. Ata: None. S. Khalid: None. A.J. Qassim: None. M. Asif: None. A. Ahmed Elamin: None. H. Khalid: None. Z. Yousaf: None. M. Javaid: None. A. Fatima: None. J. Ikram: None. A. Brett-Morris: None. A. Donato: None. M.G. Husnain: None. Background: Hyperthyroidism (HTH) is a reversible etiology of atrial fibrillation (AFib). There is no definite evidence whether the risk of thromboembolism (TE) in AFib due to HTH is higher or lower compared to AFib without HTH. Objective: To assess the clinical outcomes and risk of TE in patients with AFib due to HTH. Methods: A systematic literature search of PUBMED, Scopus and Embase on articles reporting AFib due to HTH yielded 4938 results. 294 studies fulfilled inclusion criteria, of which 274 were included in individual patient data analysis and 20 in meta-analysis. Meta-analysis assessed the proportion of patients developing TE in patients with AFib due to HTH. The protocol was registered on PROSPERO (CRD42022352406). Results: Individual patient data analysis (274 articles) Data was available for 418 patients. The mean age was 54.8±14.8 years. The majority were females (58.1%). 58.4% had newly diagnosed HTH at the time of presentation. Graves’ disease was the most common etiology of HTH (55.7%). 22% of patients had thyroid storm. ICU admission rate was 21.3%. 15.6% had concomitant high-output cardiac failure. The mean CHA2DS2-VASc score was 1.3±1.2. 30.4% of patients were discharged on anticoagulation (80.5% on warfarin and 19.5% on direct oral anticoagulants). TE events were reported in 19.4% of patients. Patients with TE events were older (57±14 vs 52.3±14.7 years; p <0.001), predominantly females (34.4% vs. 18.8%; p = 0.008) and had a higher CHA₂DS₂-VASc score (1.6±0.2 vs. 1.2±0.1; p = 0.03) compared to those who did not have TE. There were no differences in number of comorbidities, type of thyroid disease, thyroid antibody status, and TSH level between the two groups. A statistically significant correlation was found between CHA₂DS₂-VASc score and TE events on spearman correlation analysis (p = 0.02). No correlation was found between free T4 levels at presentation and TE events development at the follow-up (p = 0.33). Meta-analysis (20 studies) A total of 20 observational cohort studies encompassing 30,729 patients with AFib due to HTH were included in the proportional meta-analysis. The pooled prevalence of thromboembolic events in this population was 11.64% (95% CI: 7.88% - 15.96%). However, substantial heterogeneity was observed among the included studies (I² = 89.3%, τ² = 0.0151, p < 0.0001), suggesting considerable variability in event rates across studies. Conclusion: Patients with AFib due to HTH with advanced age are at higher risk of developing TE events. CHA₂DS₂-VASc score can be used for risk stratification in these patients and as it correlates with the risk of TE in these patients. The pooled prevalence of TE events is 11.64%. However, there is significant heterogeneity in the literature, highlighting the possibility of publication bias that may have overstated event risks. A formal trial or registry would better answer the question of incidence of TE in HTH. Presentation: Sunday, July 13, 2025