Thyrotoxic Cardiomyopathy: State of the Art. TouchREVIEWS in endocrinology Thyroid hormones, mainly triiodothyronine, have genomic and non-genomic effects on cardiomyocytes related to the contractile function of the heart. Thyrotoxicosis, which is the set of signs and symptoms derived from the excess of circulating thyroid hormones, leads to increased cardiac output and decreased systemic vascular resistance, increasing the volume of circulating blood and causing systolic hypertension. In addition, the shortening of the refractory period of cardiomyocytes produces sinus tachycardia and atrial fibrillation. This leads to heart failure. Approximately 1% of patients with thyrotoxicosis develop thyrotoxic cardiomyopathy, a rare but potentially fatal form of dilated cardiomyopathy. Thyrotoxic cardiomyopathy represents a diagnosis of exclusion, and prompt identification is crucial as it is a reversible cause of heart failure, and heart function can be recovered after achieving a euthyroid state using antithyroid drugs. Radioactive iodine therapy and surgery are not the best initial therapeutic approach. Moreover, it is important to manage cardiovascular symptoms, for which beta blockers are the first-line therapeutic option. 10.17925/EE.2023.19.1.78

131I therapy for 345 patients with refractory severe hyperthyroidism: Without antithyroid drug pretreatment. Ding Yong,Xing Jialiu,Fang Yi,Wang Yong,Zhang Youren,Long Yahong Experimental biology and medicine (Maywood, N.J.) The aim of this study is to evaluate the safety and long-term results of (131)I therapy alone for patients with refractory severe hyperthyroidism without antithyroid drug pretreatment. From January 2002 to December 2012, 408 patients with refractory severe hyperthyroidism were treated with (131)I alone. Among them, 345 were followed up for 1 to 10 years for physical examination, thyroid function, and thyroid ultrasound. Complete Blood Count (CBC) liver function, electrocardiogram, echocardiogram, and Emission Computed Tomography (ECT) thyroid imaging were performed as indicated. The 345 patients had concomitant conditions including thyrotoxic heart disease, severe liver dysfunction, enlarged thyroid weighing 80 to 400 g, severe cytopenia, and vasculitis. One to two weeks prior to (131)I therapy, all patients were given low-iodine diet. The dose of (131)I therapy was 2.59 to 6.66 MBq (70 to180 µCi) per gram of thyroid with an average of 3.83 ± 0.6 MBq (103.6 ± 16.4 µCi); and the total (131)I activity administrated for the individuals was 111 to 3507.6 MBq (3.0 to 94.8 mCi, mean 444 ± 336.7 MBq (12.0 ± 9.1 mCi)). Out of the 408 patients, 283 were cured, 15 with complete remission, and 47 with incomplete remission. No treatment failure or significant clinical worsening was noted in these patients. Our data indicated that (131)I therapy alone for patients with refractory severe hyperthyroidism without antithyroid drug pretreatment is safe and effective. 10.1177/1535370215602784

Preliminary Results of Utrasound-Guided Percutaneous Radiofrequency Ablation in the Treatment of Refractory Non-nodular Hyperthyroidism. Cardiovascular and interventional radiology PURPOSE:To assess the safety and efficacy of ultrasound-guided percutaneous radiofrequency ablation (RFA) for the treatment of refractory non-nodular hyperthyroidism. METHODS:This was a single-center retrospective study in 9 patients with refractory non-nodular hyperthyroidism (2 males, 7 females; median age, range, 36 years, 14-55 years) who underwent RFA between August 2018 and September 2020. The incidence of post-procedural complications, changes in thyroid volume, thyroid function and the use and dosages of anti-thyroid drugs, were compared pre- and post-RFA. RESULTS:All patients completed the procedure successfully, and no serious complications occurred. Three months after ablation, thyroid volumes were significantly decreased with the mean volumes of the right and left lobes reduced to 45.6% (10.9 ± 2.2 ml/23.9 ± 7.2 ml, p < 0.001) and 50.2% (10.8 ± 7.4 ml/21.5 ± 11.4 ml, p = 0.001) of the volumes within 1 week after ablation. The thyroid function was gradually improved in all patients. At 3 months post-ablation, the levels of FT3 and FT4 were returned to the normal range (FT3, 4.9 ± 1.6 pmol/L vs. 8.7 ± 4.2 pmol/L, p = 0.009; FT4, 13.1 ± 7.2 pmol/L vs. 25.9 ± 12.6 pmol/L, p = 0.038), the TR-Ab level was significantly lower (4.8 ± 3.9 vs. 16.5 ± 16.4 IU/L, p = 0.027), and the TSH level was significantly higher (0.76 ± 0.88 vs. 0.03 ± 0.06, p = 0.031) than that before-ablation. Additionally, three months after RFA, the anti-thyroid medication dosages were reduced to 31.25% compared to baseline (p < 0.01). CONCLUSION:Ultrasound-guided RFA in the treatment of refractory non-nodular hyperthyroidism was safe and effective in this small group of patients with limited follow-up. Further studies with larger cohorts and longer follow-up are needed to validate this potential new application of thyroid thermal ablation. 10.1007/s00270-023-03401-5

Risk of recurrence at the time of withdrawal of short- or long-term methimazole therapy in patients with Graves' hyperthyroidism: a randomized trial and a risk-scoring model. Endocrine PURPOSE:In Graves' disease, administration of low-dose methimazole for more than 60 months induces higher remission rates compared with the conventional duration of 12-18 months. However, the risk of recurrence and its predictors beyond 48 months of drug withdrawal are not known. The aims of this study were to determine the risk of recurrence during 84 months after withdrawal of short- or long-term methimazole therapy and a risk stratification for recurrence of hyperthyroidism. METHODS:A total of 258 patients were treated with methimazole for a median of 18 months and randomized to discontinuation of the drug(conventional short-term group; n = 128) or continuation of the treatment up to 60-120 months(long-term group; n = 130). Patients were followed for 84 months after methimazole withdrawal. Cox proportional hazards modeling was performed to identify factors associated with relapse and develop a risk-scoring model at the time of discontinuing the treatment. RESULTS:Hyperthyroidism recurred in 67 of 120(56%) of conventionally-treated patients versus 20 of 118(17%) of those who received long-term methimazole treatment, p < 0.001. Age, sex, goiter grade, triiodothyronine, thyrotropin, and thyrotropin receptor antibodies were significant predictors of recurrence in both "conventional" and "long-term" groups but free thyroxine just in the "long-term" group. The risk-scoring model had a good discrimination power (optimism corrected c-index = 0.78,95%CI = 0.73-0.82) with a range of 0-14 and sensitivity of 86% and specificity of 62% at the risk-score of eight. CONCLUSION:A relapse-free state was achieved in 83% of patients with Graves' hyperthyroidism 84 months after cessation of long-term methimazole treatment which could be predicted by some significant predictors in a simple risk-scoring system. 10.1007/s12020-023-03656-5