Prevalence and Risk Factors of Heart Failure in Patients Diagnosed with Hyperthyroidism: A Systematic Review and Meta-analysis

Objectives: Hyperthyroidism has a significant impact on the cardiovascular system, causing thyrotoxic cardiomyopathy, which is characterized by atrial fibrillation, left ventricular hypertrophy and diastolic dysfunction, and may lead to heart failure. This study aimed to investigate the prevalence and associated risk factors for heart failure in patients with hyperthyroidism. Methods: A systematic literature search was conducted on PubMed, SCOPUS and Ovid SP up until April 2023. Pooled prevalence and pooled odds ratio for risk factors were calculated using the generic inverse variance method. Results: Studies involving 30,889 patients were included in this meta-analysis. The overall prevalence of heart failure in patients with hyperthyroidism was 8% (95% confidence interval [CI]: 6-11%). Further analyses revealed that the prevalence of heart failure in patients who underwent treatment with radioactive iodine ablation, antithyroid medication and thyroidectomy was 8% (95% CI: -1 to 16%), 6% (95% CI: 2 to 11%) and 4% (95% CI: -2 to 10%), respectively. The risk factors of heart failure in hyperthyroidism include atrial fibrillation, chronic kidney disease, anaemia, hypertension, history of stroke or transient ischaemic attack, history of coronary artery disease and diabetes mellitus. Conclusion: Heart failure occurs in 8% of patients with hyperthyroidism, with the most common risk factor being atrial fibrillation.