MACE and Hyperthyroidism Treated With Medication, Radioactive Iodine, or Thyroidectomy

Importance

Excessive thyroid hormones from hyperthyroidism increase cardiovascular risks. Among 3 available treatments for hyperthyroidism, comparisons of long-term outcomes associated with antithyroid drugs (ATDs), radioactive iodine (RAI), and surgery to treat newly diagnosed hyperthyroidism are lacking.

Objective

To compare risks of major adverse cardiovascular events (MACE) and all-cause mortality among patients with hyperthyroidism treated with ATDs, RAI, or surgery.

Design, Setting, and Participants

This nationwide cohort study used the Taiwan National Health Insurance Research Database. Patients aged 20 years or older with newly diagnosed hyperthyroidism between 2011 and 2020 were enrolled. Treatment groups were determined within 18 months from diagnosis, with follow-up until the development of MACE, death, or the end date of the database, whichever came first. Data were analyzed from October 2022 through December 2023.

Exposures

The ATD group received ATDs only. RAI and surgery groups could receive ATDs before treatment. Anyone who underwent thyroid surgery without RAI was classified into the surgery group and vice versa.

Main Outcomes and Measures

The primary outcomes included MACE (a composite outcome of acute myocardial infarction, stroke, heart failure, and cardiovascular mortality) and all-cause mortality.

Results

Among 114 062 patients with newly diagnosed hyperthyroidism (mean [SD] age, 44.1 [13.6] years; 83 505 female [73.2%]), 107 052 patients (93.9%) received ATDs alone, 1238 patients (1.1%) received RAI, and 5772 patients (5.1%) underwent surgery during a mean (SD) follow-up of 4.4 (2.5) years. Patients undergoing surgery had a significantly lower risk of MACE (hazard ratio [HR] = 0.76; 95% CI, 0.59-0.98; P = .04), all-cause mortality (HR = 0.53; 95% CI, 0.41-0.68; P < .001), heart failure (HR = 0.33; 95% CI, 0.18-0.59; P < .001), and cardiovascular mortality (HR = 0.45; 95% CI, 0.26-0.79; P = .005) compared with patients receiving ATDs. Compared with ATDs, RAI was associated with lower MACE risk (HR = 0.45; 95% CI, 0.22-0.93; P = .03). Risks for acute myocardial infarction and stroke did not significantly differ between treatment groups.

Conclusions and Relevance

In this study, surgery was associated with lower long-term risks of MACE and all-cause mortality, while RAI was associated with a lower MACE risk compared with ATDs.

A comparison of cardiovascular disease, cancer, mortality, and Graves' ophthalmopathy following treatment for hyperthyroidism: A Bayesian network meta-analysis

OBJECTIVES

This network meta-analysis aimed to evaluate the association of anti-thyroid drugs (ATD), radioactive iodine (RAI), and thyroidectomy with subsequent outcomes in patients with newly-diagnosed hyperthyroidism.

METHODS

The Ovid Medline, Ovid Embase, and Cochrane Library databases were searched for observational studies and randomized controlled trials. Included studies were published on or before 1st May 2022 involving at least two of the treatments among ATD, RAI, and thyroidectomy for hyperthyroidism. Pairwise comparisons and Bayesian network meta-analysis were used to estimate hazard ratios (HRs) and their credible interval (CrI) of outcomes, including cardiovascular disease (CVD), cancer, overall mortality, and Graves' ophthalmopathy (GO).

RESULTS

A total of 22 cohort studies with 131,297 hyperthyroidism patients were included. Thyroidectomy was associated with lower risks of mortality and GO than ATD (HR = 0.54, 95% CrI: 0.31, 0.96; HR = 0.31, 95% CrI: 0.12, 0.64) and RAI (HR = 0.62, 95% CrI: 0.41, 0.95; HR = 0.18, 95% CrI: 0.07, 0.35). RAI had a higher risk of GO (HR = 1.70, 95% CrI: 1.02, 2.99) than ATD treatment.

CONCLUSIONS

This Bayesian network meta-analysis indicated that thyroidectomy was associated with lower risks of mortality and GO in newly-diagnosed hyperthyroid patients compared to ATD and RAI. Relative to ATD, RAI therapy increased the risk of GO.

Hyperthyroidism: A Review

Importance

Overt hyperthyroidism, defined as suppressed thyrotropin (previously thyroid-stimulating hormone) and high concentration of triiodothyronine (T3) and/or free thyroxine (FT4), affects approximately 0.2% to 1.4% of people worldwide. Subclinical hyperthyroidism, defined as low concentrations of thyrotropin and normal concentrations of T3 and FT4, affects approximately 0.7% to 1.4% of people worldwide. Untreated hyperthyroidism can cause cardiac arrhythmias, heart failure, osteoporosis, and adverse pregnancy outcomes. It may lead to unintentional weight loss and is associated with increased mortality.

Observations

The most common cause of hyperthyroidism is Graves disease, with a global prevalence of 2% in women and 0.5% in men. Other causes of hyperthyroidism and thyrotoxicosis include toxic nodules and the thyrotoxic phase of thyroiditis. Common symptoms of thyrotoxicosis include anxiety, insomnia, palpitations, unintentional weight loss, diarrhea, and heat intolerance. Patients with Graves disease may have a diffusely enlarged thyroid gland, stare, or exophthalmos on examination. Patients with toxic nodules (ie, in which thyroid nodules develop autonomous function) may have symptoms from local compression of structures in the neck by the thyroid gland, such as dysphagia, orthopnea, or voice changes. Etiology can typically be established based on clinical presentation, thyroid function tests, and thyrotropin-receptor antibody status. Thyroid scintigraphy is recommended if thyroid nodules are present or the etiology is unclear. Thyrotoxicosis from thyroiditis may be observed if symptomatic or treated with supportive care. Treatment options for overt hyperthyroidism from autonomous thyroid nodules or Graves disease include antithyroid drugs, radioactive iodine ablation, and surgery. Treatment for subclinical hyperthyroidism is recommended for patients at highest risk of osteoporosis and cardiovascular disease, such as those older than 65 years or with persistent serum thyrotropin level less than 0.1 mIU/L.

Conclusions and Relevance

Hyperthyroidism affects 2.5% of adults worldwide and is associated with osteoporosis, heart disease, and increased mortality. First-line treatments are antithyroid drugs, thyroid surgery, and radioactive iodine treatment. Treatment choices should be individualized and patient centered.

Long term outcome after toxic nodular goitre

BACKGROUND

The purpose of treating toxic nodular goitre (TNG) is to reverse hyperthyroidism, prevent recurrent disease, relieve symptoms and preserve thyroid function. Treatment efficacies and long-term outcomes of antithyroid drugs (ATD), radioactive iodine (RAI) or surgery vary in the literature. Symptoms often persist for a long time following euthyroidism, and previous studies have demonstrated long-term cognitive and quality of life (QoL) impairments. We report the outcome of treatment, rate of cure (euthyroidism and hypothyroidism), and QoL in an unselected TNG cohort.

METHODS

TNG patients (n = 638) de novo diagnosed between 2003-2005 were invited to engage in a 6-10-year follow-up study. 237 patients responded to questionnaires about therapies, demographics, comorbidities, and quality of life (ThyPRO). Patients received ATD, RAI, or surgery according clinical guidelines.

RESULTS

The fraction of patients cured with one RAI treatment was 89%, and 93% in patients treated with surgery. The rate of levothyroxine supplementation for RAI and surgery, at the end of the study period, was 58% respectively 64%. Approximately 5% of the patients needed three or more RAI treatments to be cured. The patients had worse thyroid-related QoL scores, in a broad spectrum, than the general population.

CONCLUSION

One advantage of treating TNG with RAI over surgery might be lost due to the seemingly similar incidence of hypothyroidism. The need for up to five treatments is rarely described and indicates that the treatment of TNG can be more complex than expected. This circumstance and the long-term QoL impairments are reminders of the chronic nature of hyperthyroidism from TNG.

Management of Graves' hyperthyroidism: present and future

INTRODUCTION

Graves' disease (GD) is an autoimmune disorder due to loss of tolerance to the thyrotropin receptor (TSHR) and ultimately caused by stimulatory TSHR antibodies (TSHR-Ab). GD may be associated with extrathyroidal manifestations, mainly Graves' orbitopathy. Treatment of GD relies on antithyroid drugs (ATDs), radioactive iodine (RAI), thyroidectomy. The major ATD limitation is the high recurrence rate after treatment. The major drawback of RAI and thyroidectomy is the inevitable development of permanent hypothyroidism.

AREAS COVERED

Original articles, clinical trials, systematic reviews, meta-analyses from 1980 to 2021 were searched using the following terms: Graves' disease, management of Graves' disease, antithyroid drugs, radioactive iodine, thyroidectomy, Graves' orbitopathy, thyroid-eye disease.

EXPERT OPINION

ATDs are the first-line treatment worldwide, are overall safe and usually given for 18-24 months, long-term treatment may decrease relapses. RAI is safe, although associated with a low risk of GO progression, particularly in smokers. Thyroidectomy requires skilled and high-volume surgeons. Patients play a central role in the choice of treatment within a shared decision-making process. Results from targeted therapies acting on different steps of the autoimmune process, including iscalimab, ATX-GD-59, rituximab, blocking TSHR-Ab, small molecules acting as antagonists of the TSHR, are preliminary or preclinical, but promising in medium-to-long perspective.

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.

OUP accepted manuscript

Background

The relationship between good early control of thyroid hormone levels after thyroidectomy for Graves’ disease (GD) and subsequent risks of mortality and morbidities is not well known. The aim of this study was to examine the association between thyroid hormone levels within a short interval after surgery and long-term mortality and morbidity risks from a population-based database.

Methods

Patients with GD who underwent complete/total thyroidectomy between 2006 and 2018 were selected from the Hong Kong Hospital Authority clinical management system. All patients were classified into three groups (euthyroidism, hypothyroidism, and hyperthyroidism) according to their thyroid hormone levels at 6, 12, and 24 months after surgery. Cox proportional hazards models were performed to compare the risks of all-cause mortality, cardiovascular disease (CVD), Graves’ ophthalmopathy, and cancer.

Results

Over a median follow-up of 68 months with 5709 person-years, 949 patients were included for analysis (euthyroidism, n = 540; hypothyroidism, n = 282; and hyperthyroidism, n = 127). The hypothyroidism group had an increased risk of CVD (HR = 4.20, 95 per cent c.i. 2.37 to 7.44, P < 0.001) and the hyperthyroidism group had an increased risk of cancer (HR = 2.14, 95 per cent c.i. 1.55 to 2.97, P < 0.001) compared with the euthyroidism group. Compared with patients obtaining euthyroidism both at 6 months and 12 months, the risk of cancer increased in patients who achieved euthyroidism at 6 months but had an abnormal thyroid status at 12 months (HR = 2.33, 95 per cent c.i. 1.51 to 3.61, P < 0.001) and in those who had abnormal thyroid status at 6 months but achieved euthyroidism at 12 months (HR = 2.52, 95 per cent c.i. 1.60 to 3.97, P < 0.001).

Conclusions

This study showed a higher risk of CVD in postsurgical hypothyroidism and a higher risk of cancer in hyperthyroidism compared with achieving euthyroidism early after thyroidectomy. Patients who were euthyroid at 6 months and 12 months had better outcomes than those achieving euthyroidism only at 6 months or 12 months. Attaining biochemical euthyroidism early after thyroidectomy should become a priority.

Cancer Risk After Radioactive Iodine Treatment for Hyperthyroidism: A Systematic Review and Meta-analysis

IMPORTANCE

Whether radioactive iodine (RAI) therapy for hyperthyroidism can increase cancer risk remains a controversial issue in medicine and public health.

OBJECTIVES

To examine site-specific cancer incidence and mortality and to evaluate the radiation dose-response association after RAI treatment for hyperthyroidism.

DATA SOURCES

The Medline and Cochrane Library electronic databases, using the Medical Subject Headings terms and text keywords, and Embase, using Emtree, were screened up to October 2020.

STUDY SELECTION

Study inclusion criteria were as follows: (1) inclusion of patients treated for hyperthyroidism with RAI and followed up until cancer diagnosis or death, (2) inclusion of at least 1 comparison group composed of individuals unexposed to RAI treatment (eg, the general population or patients treated for hyperthyroidism with thyroidectomy or antithyroid drugs) or those exposed to different administered doses of RAI, and (3) inclusion of effect size measures (ie, standardized incidence ratio [SIR], standardized mortality ratio [SMR], hazard ratio [HR], or risk ratio [RR]).

DATA EXTRACTION AND SYNTHESIS

Two independent investigators extracted data according to the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Overall quality assessment followed the recommendations of United Nations Scientific Committee on the Effects of Atomic Radiation. The SIR and SMRs and the RRs and HRs were pooled using random-effects meta-analysis.

MAIN OUTCOMES AND MEASURES

Cancer incidence and mortality for exposure vs nonexposure to RAI therapy and by level of RAI administered activity.

RESULTS

Based on data from 12 studies including 479 452 participants, the overall pooled cancer incidence ratio was 1.02 (95% CI, 0.95-1.09) and the pooled cancer mortality ratio was 0.98 (95% CI, 0.92-1.04) for exposure vs nonexposure to RAI therapy. No statistically significant elevations in risk were observed for specific cancers except thyroid cancer incidence (SIR, 1.86; 95% CI, 1.19-2.92) and mortality (SMR, 2.22; 95% CI, 1.37-3.59). However, inability to control for confounding by indication and other sources of bias were important limitations of studies comparing RAI exposure with nonexposure. In dose-response analysis, RAI was significantly associated with breast and solid cancer mortality (breast cancer mortality, per 370 MBq: 1.35; P = .03; solid cancer mortality, per 370 MBq: 1.14; P = .01), based on 2 studies.

CONCLUSIONS AND RELEVANCE

In this meta-analysis, the overall pooled cancer risk after exposure to RAI therapy vs nonexposure was not significant, whereas a linear dose-response association between RAI therapy and solid cancer mortality was observed. These findings suggest that radiation-induced cancer risks following RAI therapy for hyperthyroidism are small and, in observational studies, may only be detectable at higher levels of administered dose.

Outcomes of Graves' Disease Patients Following Antithyroid Drugs, Radioactive Iodine, or Thyroidectomy as the First-line Treatment

BACKGROUND

The long-term outcomes of first-line choice among ATD, RAI, and thyroidectomy for GD patients remain unclear.

OBJECTIVE

To compare the long-term morbidity, mortality, relapse, and costs of GD patients receiving first-line treatment.

METHODS

A population-based retrospective cohort of GD patients initiating first-line treatment with ATD, RAI, or thyroidectomy as a first-line primary treatment between 2006 and 2018 from Hong Kong Hospital Authority was analyzed. Risks of all-cause mortality, CVD, AF, psychological disease, diabetes, and hypertension were estimated using Cox proportional hazards regression models. The 10-year healthcare costs, change of comorbidities, and risk of relapse were compared across treatments.

RESULTS

Over a median follow-up of 90 months with 47,470 person-years, 6385 patients (ATD, 74.93%; RAI, 19.95%; thyroidectomy, 5.12%) who received first-line treatment for GD were analyzed. Compared with ATD group, patients who had undergone surgery had significantly lower risks of all-cause mortality [hazard ratio (HR) = 0.363, 95% confidence interval (CI) = 0.332-0.396], CVD (HR = 0.216, 95% CI = 0.195-0.239), AF (HR = 0.103, 95% CI = 0.085-0.124), psychological disease (HR = 0.279, 95% CI = 0.258-0.301), diabetes (HR = 0.341, 95% CI = 0.305-0.381), and hypertension (HR = 0.673, 95% CI = 0.632-0.718). Meanwhile, RAI group was also associated with decreased risks of all-cause mortality (HR = 0.931, 95% CI = 0.882-0.982), CVD (HR = 0.784, 95% CI = 0.742-0.828), AF (HR = 0.622, 95% CI = 0.578-0.67), and psychological disease (HR = 0.895, 95% CI = 0.855-0.937). The relapse rate was 2.41% in surgery, 75.60% in ATD, and 19.53% in RAI group. The surgery group was observed with a significant lower Charlson Comorbidity Index score than the other 2 groups at the tenth-year follow-up. The mean 10-year cumulative healthcare costs in ATD, RAI, and surgery group was US$23915, US$24260, and US$20202, respectively.

CONCLUSIONS

GD patients who received surgery as an initial treatment appeared to have lower chances of all-cause mortality, CVD, AF, psychological disease, diabetes, and hypertension in the long-term when compared to those treated with ATD or RAI. The surgery group had the lowest relapse and direct healthcare costs among the 3 treatment modalities. This long-term cohort study suggested surgery may have a larger role to play as an initial treatment for GD patients.

Mortality Risk After Radioiodine Therapy for Hyperthyroidism: A Systematic Review and Meta-Analysis

OBJECTIVE

Radioiodine has been increasingly used to treat hyperthyroidism for many years. Although widely regarded as an effective therapy, radioiodine treatment for hyperthyroidism has been suspected to be associated with the risk of mortality. This study aimed to quantify the mortality outcomes in patients who were treated for hyperthyroidism with radioiodine.

METHODS

Systematic search and meta-analysis were performed to determine the risk of mortality in patients treated with radioiodine for hyperthyroidism. Relevant studies were searched through August 2020 and selected in accordance with the inclusion criteria.

RESULTS

A total of 13 studies were identified. The summary odds ratios (ORs) showed an increased risk of all-cause mortality in patients who were treated with radioiodine for hyperthyroidism (OR = 1.20; 95% CI = 1.07-1.35). The risk of death attributed to all forms of circulatory, respiratory, and endocrine and metabolic diseases was significantly increased, with summary ORs of 1.23 (95% CI, 1.12-1.35), 1.43 (95% CI, 1.17-1.75), and 2.38 (95% CI, 1.85-3.06), respectively. The summary ORs revealed no significant association between radioiodine treatment for hyperthyroidism and the risk of cancer mortality (OR = 1.03; 95% CI, 0.98-1.09). Radioiodine treatment for hyperthyroidism was not associated with the risk of mortality from breast, respiratory system, gastrointestinal, and genitourinary cancers.

CONCLUSION

Radioiodine treatment for hyperthyroidism is associated with the risk of all-cause mortality but not cancer mortality. Future research needs to address the causes of hyperthyroidism, effects of radioiodine therapy, and potential effects of confounding to identify causality.

Cardiovascular Outcomes of Thyroidectomy or Radioactive Iodine Ablation for Graves' Disease

BACKGROUND

Treatment options for Graves' disease (GD) include medical management with antithyroid medications, radioactive iodine (RAI) ablation, or total thyroidectomy (TT). Definitive treatment with RAI ablation may be associated with worse cardiovascular morbidity and mortality than TT. We sought to determine the rate of cardiovascular morbidity before and after definitive treatment for GD.

METHODS

This study is a retrospective single-institution study of sequential adult patients with GD from 2012 to 2018 treated with RAI ablation or TT. Patients with prior thyroid surgery or RAI ablation with subsequent thyroidectomy were excluded. Demographic and clinical variables were collected from diagnosis of GD to last follow-up. Data analysis was performed with descriptive statistics, univariate analysis with Fisher's exact test for categorical variables and the Mann-Whitney U test for continuous variables.

RESULTS

One-hundred and eighty-four patients underwent definitive treatment for GD during the study period, of which 164 met inclusion criteria. One hundred and ten patients (67%) in the study group had TT and 54 (33%) had RAI ablation with a mean dose of 18.4 mCi (standard deviation 6.1). There were no differences in clinical or demographic factors in patients undergoing RAI ablation versus TT for definitive treatment including age, sex, thyroid-stimulating hormone level, free thyroxine level, or thyroid-stimulating immunoglobulin level at time of diagnosis, nor was there any difference in pretreatment cardiovascular comorbidity. Patients with TT had higher rates of resolution of arrhythmia after treatment than those undergoing RAI ablation, P = 0.02. There were no differences in treatment-related complications between the groups.

CONCLUSIONS

For patients undergoing definitive treatment for GD, TT is associated with improved rate of resolution of cardiac arrhythmia compared with RAI ablation.

Management of Graves’ Hyperthyroidism: More Than a Century of Progression

Context: There are three therapeutic modalities for the management of Graves’ disease (GD), including thyroid surgery, radioactive iodine (RAI), and antithyroid drugs (ATDs). We aimed to briefly review the history of these treatment strategies and their advantages and disadvantages. Evidence Acquisition: We searched PubMed for English language articles using pertinent search terms. Results: Each treatment modality for GD is accompanied by several advantages and disadvantages. Nowadays, ATDs are the most commonly prescribed therapy for GD worldwide. The lack of well-designed, large RCTs comparing three different treatments for hyperthyroidism concerning various short-term and long-term outcomes has led to remarkable uncertainty in the preference of each of these treatments, as is evident in relevant guidelines from different societies. Recently, the efficacy and safety of long-term use of ATDs have been documented. Conclusions: Pros and cons of each therapeutic modality for Graves’ hyperthyroidism should be taken into account during the physician-patient discussion to select the primary treatment. Considering recent data about the long-term efficacy and safety of ATDs, it seems that the appropriate selection of Graves’ patients for long-term ATD therapy can be a new avenue in the treatment and even cure of GD.

Current controversies in the management of Graves' hyperthyroidism

Introduction: The management of Graves' disease centers on the use of effective and well-established therapies, namely thionamide antithyroid drugs, radioactive iodine, and thyroidectomy. Optimal treatment strategies are however controversial and vary significantly across centers.Areas covered: This review addresses specific controversies in Graves' disease management including the choice of primary therapy, the approach to women planning pregnancy, and optimal strategies for antithyroid drug and radioiodine therapy.Expert opinion: Important considerations in choosing therapy include treatment efficacy, adverse effects, patient convenience, and resource settings. Recent data suggest that early and effective control of hyperthyroidism is key to improving cardiovascular morbidity and mortality. Studies addressing cancer risk in radioiodine-treated patients face methodological challenges and require clarification in appropriately designed studies. Remission rates with antithyroid drugs are comparable when thionamides are used alone (titration-regimen) or in combination with levothyroxine (block and replace) and can be optimized by extending treatment for at least 12-18 months. Fixed and calculated radioiodine activity regimens are both effective but entail a trade-off between convenience and precision in the administered activity. Optimal preconception strategies are still evolving but ablative treatment in advance of pregnancy offers the most pragmatic means of reducing adverse effects of hyperthyroidism in subsequent pregnancy.

Should radioiodine now be first line treatment for Graves' disease?

Background

Radioiodine represents a cost-effective treatment option for Graves’ disease. In the UK, it is traditionally reserved for patients who relapse after initial thionamide therapy. In a change from current practice, the new guidelines of the National Institute for Health and Care Excellence (NICE) recommends that radioiodine should now be first line therapy for Graves’ disease. However, the safety of radioiodine with respect to long-term mortality risk has been the subject of recent debate. This analysis examines evidence from treatment related mortality studies in hyperthyroidism and discusses their implications for future Graves’ disease treatment strategies.

Main body

Some studies have suggested an excess mortality in radioiodine treated cohorts compared to the background population. In particular, a recent observational study reported a modest increase in cancer-related mortality in hyperthyroid patients exposed to radioiodine. The interpretation of these studies is however constrained by study designs that lacked thionamide control groups or information on thyroid status and so could not distinguish the effect of treatment from disease. Two studies have shown survival advantages of radioiodine over thionamide therapy, but these benefits were only seen when radioiodine was successful in controlling hyperthyroidism. Notably, increased mortality was associated with uncontrolled hyperthyroidism irrespective of therapy modality.

Conclusions

Early radioiodine treatment will potentially reduce mortality and should be offered to patients with severe disease. However, thionamides are still suitable for patients with milder disease, contraindications to radioiodine, or individuals who choose to avoid permanent hypothyroidism. Ultimately, a patient individualised approach that prioritises early and sustained control of hyperthyroidism will improve long-term outcomes regardless of the therapy modality used.

The Long-Term Outcome of Treatment for Graves' Hyperthyroidism

Background: The treatment efficacy of antithyroid drug (ATD) therapy, radioactive iodine (¹³¹I), or surgery for Graves' hyperthyroidism is well described. However, there are a few reports on the long-term total outcome of each treatment modality regarding how many require levothyroxine supplementation, the need of thyroid ablation, or the individual patient's estimation of their recovery. Methods: We conducted a pragmatic trial to determine the effectiveness and adverse outcome in a patient cohort newly diagnosed with Graves' hyperthyroidism between 2003 and 2005 (n = 2430). The patients were invited to participate in a longitudinal study spanning 8 ± 0.9 years (mean ± standard deviation) after diagnosis. We were able to follow 1186 (60%) patients who had been treated with ATD, ¹³¹I, or surgery. We determined the mode of treatment, remission rate, recurrence, quality of life, demographic data, comorbidities, and lifestyle factors through questionnaires and a review of the individual's medical history records. Results: At follow-up, the remission rate after first-line treatment choice with ATD was 45.3% (351/774), with ¹³¹I therapy 81.5% (324/264), and with surgery 96.3% (52/54). Among those patients who had a second course of ATD, 29.4% achieved remission (vs. the 45.3% after the first course of ATD). The total number of patients who had undergone ablative treatment was 64.3% (763/1186), of whom 23% (278/1186) had received surgery, 43% (505/1186) had received ¹³¹I therapy, including 2% (20/1186) who had received both surgery and ¹³¹I. Patients who received ATD as first-line treatment and possibly additional ATD had 49.7% risk (385/774) of having undergone ablative treatment at follow-up. Levothyroxine replacement was needed in 23% (81/351) of the initially ATD treated in remission, in 77.3% (204/264) of the ¹³¹I treated, and in 96.2% (50/52) of the surgically treated patients. Taken together after 6-10 years, and all treatment considered, normal thyroid hormone status without thyroxine supplementation was only achieved in 35.7% (423/1186) of all patients and in only 40.3% of those initially treated with ATD. The proportion of patients that did not feel fully recovered at follow-up was 25.3%. Conclusion: A patient selecting ATD therapy as the initial approach in the treatment of Graves' hyperthyroidism should be informed that they have only a 50.3% chance of ultimately avoiding ablative treatment and only a 40% chance of eventually being euthyroid without thyroid medication. Surprisingly, 1 in 4 patients did not feel fully recovered after 6-10 years. The treatment for Graves' hyperthyroidism, thus, has unexpected long-term consequences for many patients.

Primary therapy of Graves' disease and cardiovascular morbidity and mortality: a linked-record cohort study

BACKGROUND

Graves' disease is routinely treated with antithyroid drugs, radioiodine, or surgery, but whether the choice of initial therapy influences long-term outcomes is uncertain. We evaluated cardiovascular morbidity and mortality according to the method and effectiveness of primary therapy in Graves' disease.

METHODS

In this retrospective cohort study, we identified patients with hyperthyroidism, diagnosed between Jan 1, 1998, and Dec 31, 2013, from a thyroid-stimulating hormone (TSH)-receptor antibody (TRAb) test register in south Wales, UK, and imported their clinical data into the All-Wales Secure Anonymised Information Linkage (SAIL) Databank (Swansea University, Swansea, UK). Patients with Graves' disease, defined by positive TRAb tests, were selected for the study, and their clinical data were linked with outcomes in SAIL. We had no exclusion criteria. Patients were matched by age and sex to a control population (1:4) in the SAIL database. Patients were grouped by treatment within 1 year of diagnosis into the antithyroid drug group, radioiodine with resolved hyperthyroidism group (radioiodine group A), or radioiodine with unresolved hyperthyroidism group (radioiodine group B). We used landmark Kaplan-Meier and Cox regression models to analyse the association of treatment with the primary outcome of all-cause mortality and the secondary outcome of major adverse cardiovascular events (myocardial infarction, heart failure, ischaemic stroke, or death) with the landmark set at 1 year after diagnosis. We analysed the association between outcomes and concentration of TSH using Cox regression and outcomes and free thyroxine (FT4) concentration using restricted cubic-spline regression models.

FINDINGS

We extracted patient-level data on 4189 patients (3414 [81·5%] females and 775 [18·5%] males) with Graves' disease and 16 756 controls (13 656 [81·5%] females and 3100 [18·5%] males). In landmark analyses, 3587 patients were in the antithyroid drug group, 250 were in radioiodine group A, 182 were in radioiodine group B. Patients had increased all-cause mortality compared with controls (hazard ratio [HR] 1·22, 95% CI 1·05-1·42). Compared with patients in the antithyroid drug group, mortality was lower among those in radioiodine group A (HR 0·50, 95% CI 0·29-0·85), but not for those in radioiodine group B (HR 1·51, 95% CI 0·96-2·37). Persistently low TSH concentrations at 1 year after diagnosis were associated with increased mortality independent of treatment method (HR 1·55, 95% CI 1·08-2·24). Spline regressions showed a positive non-linear relationship between FT4 concentrations at 1 year and all-cause mortality.

INTERPRETATION

Regardless of the method of treatment, early and effective control of hyperthyroidism among patients with Graves' disease is associated with improved survival compared with less effective control. Rapid and sustained control of hyperthyroidism should be prioritised in the management of Graves' disease and early definitive treatment with radioiodine should be offered to patients who are unlikely to achieve remission with antithyroid drugs alone.

FUNDING

National Institute for Social Care and Health Research, Wales.