Incidence, risk factors, natural history and outcomes of heart failure in patients with Graves' disease

Incidence, Risk Factors, and Outcomes of Incident Atrial Fibrillation in Patients With Graves Disease

OBJECTIVE

To describe the incidence, risk factors, and outcomes of incident atrial fibrillation (AF) in Graves disease (GD).

PATIENTS AND METHODS

Patients with GD between January 1, 2009, and December 31, 2019, were included retrospectively. We defined GD-related AF as AF diagnosed less than or equal to 30 days before or any time after GD. Late-onset AF was defined as incident AF diagnosed more than 90 days after GD.

RESULTS

Of 1371 patients with GD, AF occurred in 139 patients. Late-onset AF occurred in 32 (23.0%) of AF cases, of which 16 (50.0%) had attained euthyroidism. Independent risk factors were age (HR, 1.05; 95% CI, 1.03-1.06 per year), overt hyperthyroidism (free T4 >1.7 ng/dL; HR, 2.75; 95% CI, 1.38 to 5.46), and male sex (HR, 2.30; 95% CI, 1.54 to 3.43) for early AF. These were age (HR, 1.08; 95% CI, 1.05 to 1.119 per year), chronic obstructive pulmonary disease (HR, 3.47; 95% CI, 1.36 to 5.54), and heart failure (HR, 5.86; 95% CI, 2.39 to 14.38) for late AF. Atrial fibrillation in GD was associated with higher mortality (HR, 16.32; 95% CI, 4.66 to 56.58), acute coronary syndrome/stable angina events (HR, 3.89; 95% CI, 1.23 to 12.31), and cardiac hospitalizations (HR, 15.39; 95% CI, 8.17 to 29.00) when adjusted to age, sex, and pre-existing AF.

CONCLUSION

Late-onset AF comprised one-quarter of GD-related AF cases requiring surveillance even after restoring euthyroidism. Risk factors for AF in GD are similar to those in the general population although overt hyperthyroidism conferred the highest risk, especially for early AF. Treatment with thionamide was associated with late AF.

Cardiovascular Health by Graves' Disease Management Modality - Surgery Versus Radioactive Iodine Versus Antithyroid Medications: A Network Meta-Analysis

INTRODUCTION

Graves' disease is an autoimmune disorder of the thyroid gland associated with the overproduction of thyroid hormones. Excess secretion of thyroid hormones leads to cardiovascular consequences. Treatment options include antithyroid medications (ATM), radioactive iodine (RAI) ablation, and total thyroidectomy. We examined the cardiovascular outcomes following Graves' disease management modality.

METHODS

A systematic search was performed up to September 22nd, 2021, using PubMed, EMBASE, and Web of Science databases. We conducted a network meta-analysis analyzing cardiovascular outcomes of interest, including congestive heart failure (CHF), arrhythmia, atrial fibrillation (AF), and hypertension.

RESULTS

Three studies were included in this analysis totaling 6700 patients with Graves' disease, of which 74% were female. The mean age was 44.34 y. When compared to pretreatment, management options lowered the risk of maintaining arrhythmia 81% with surgery (relative risk [RR] = 0.19; 95% confidence interval [CI] = 0.12 to 0.31), 67% with ATM (RR = 0.33; 95% CI = 0.23 to 0.49), and 50% with RAI (RR = 0.50; 95% CI = 0.13 to 1.95). Risk of maintaining CHF was reduced 80% with surgery (RR = 0.20; 95% CI = 0.08 to 0.49), 41% with ATM (RR = 0.59; 95%CI = 0.52 to 0.67), and only 7% with RAI (RR = 0.93; 95%CI = 0.68 to 1.26). Treatment-ranking analysis found all parameters, including CHF, arrhythmia, AF, and hypertension, to be in favor of surgical treatment over medical treatment and RAI ablation.

CONCLUSIONS

This is the first network meta-analysis analyzing the cardiovascular outcomes in Graves' disease patients by treatment option. Our study demonstrated that surgery is superior to RAI and medical treatment.

Graves' disease as a driver of depression: a mechanistic insight

Graves' disease (GD) is characterized by diffuse enlargement and overactivity of the thyroid gland, which may be accompanied by other physical symptoms. Among them, depression can dramatically damage patients' quality of life, yet its prevalence in GD has not received adequate attention. Some studies have established a strong correlation between GD and increased risk of depression, though the data from current study remains limited. The summary of mechanistic insights regarding GD and depression has underpinned possible pathways by which GD contributes to depression. In this review, we first summarized the clinical evidence that supported the increased prevalence of depression by GD. We then concentrated on the mechanistic findings related to the acceleration of depression in the context of GD, as mounting evidence has indicated that GD promotes the development of depression through various mechanisms, including triggering autoimmune responses, inducing hormonal disorders, and influencing the thyroid-gut-microbiome-brain axis. Finally, we briefly presented potential therapeutic approaches to decreasing the risk of depression among patients with GD.

High triiodothyronine levels induce myocardial hypertrophy via BAFF overexpression

Activated B cells contribute to heart diseases, and inhibition of B‐cell activating factor (BAFF) expression is an effective therapeutic target for heart diseases. Whether activated B cells participate in the development and progression of hyperthyroid heart disease, and what induces B cells activation in hyperthyroidism are unknown. The present study aimed to determine the roles of BAFF overexpression induced by high concentrations of triiodothyronine (T3) in the pathogenesis of hyperthyroid heart disease. Female C57BL/6J mice were subcutaneously injected with T3 for 6 weeks, and BAFF expression was inhibited using shRNA. Protein and mRNA expression of BAFF in mouse heart tissues evaluated via immunohistochemistry, western blotting and polymerase chain reaction (PCR). Proportions of B cells in mouse cardiac tissue lymphocytes were quantified via flow cytometry. Morphology and left ventricle function were assessed using pathological sections and echocardiography, respectively. Here, we demonstrate that compared with the control group, the proportion of myocardial B cells was larger in the T3 group; immunohistochemistry, western blotting and PCR analyses revealed increased protein and mRNA expression levels of TNF‐α and BAFF in heart tissues of the T3 group. Compared with the normal controls group, in the T3 group, the diameter of myocardial cells and some echocardiographic values significantly increased and hypertrophy and structural disorder were noticeable. Our results revealed that elevated levels of circulating T3 can promote the expression of BAFF in myocardial cells and can lead to B‐cell activation, an elevated inflammatory response and ventricular remodelling.

Thyroid disorders and cardiovascular manifestations: an update

Cardiovascular disease (CVD) remains the leading cause of death worldwide, representing a major health, social, and economic issue. Thyroid disorders are very common and affect >10% of the adult population in total. The aim of this review is to describe the physiologic role of thyroid hormones on cardiovascular system, to present cardiovascular manifestations in patients with thyroid disorders, emphasizing in molecular mechanisms and biochemical pathways, and to summarize current knowledge of treatment options. Thyroid hormone receptors are located both in myocardium and vessels, and changes in their concentrations affect cardiovascular function. Hyperthyroidism or hypothyroidism, both clinical and subclinical, without the indicated therapeutical management, may contribute to the progression of CVD. According to recent studies, even middle changes in thyroid hormones levels increase cardiovascular mortality from 20% to 80%. In more details, thyroid disorders seem to have serious effects on the cardiovascular system via plenty mechanisms, including dyslipidemia, hypertension, systolic and diastolic myocardial dysfunction, as well endothelial dysfunction. On top of clinical thyroid disorders management, current therapeutics focus on younger patients with subclinical hypothyroidism and elderly patients with subclinical hyperthyroidism.