BACKGROUND
Hyperthyroidism is a condition whereby the thyroid gland becomes overactive and makes too much thyroid hormone. The most common causes of hyperthyroidism in the United States are Graves’ disease and toxic nodules. There are several options available for treating hyperthyroidism including antithyroid medications (ATD), such as methimazole and propylthiouracil (PTU), thyroid surgery, and radioactive iodine therapy (RAI) to destroy the thyroid. Antithyroid medications are becoming the most common treatment option, at least initially, but depending on the cause of hyperthyroidism and patient and physician preferences, the other treatment options may be recommended.

Heart racing/palpitations are common symptoms of hyperthyroidism. Indeed, hyperthyroidism has been associated with increased risk of atrial fibrillation, heart attacks and death. This study sought to determine if treatment choice impacts major adverse cardiac events (MACE) and death rates (all-cause mortality). These investigators examined long term MACE and all-cause mortality in newly diagnosed hyperthyroid subjects in Taiwan based on treatment choice.

THE FULL ARTICLE TITLE
Peng CC-H, et al. MACE and hyperthyroidism treated with medication, radioactive iodine, or thyroidectomy. JAMA Netw Open 2024;7:e240904. PMID: 38436957. doi: 10.1001/jamanetworkopen.2024.0904.

SUMMARY OF THE STUDY
The study was a nationwide study using the Taiwan National Health Insurance Database. Subjects aged 20 years or older with new hyperthyroidism diagnosed between 2011 and 2020 were examined according to the treatment they received (ATD, surgery, or RAI) for their hyperthyroidism. Subjects in the ATD group only received ATD treatment while those in the surgical or RAI groups could have received ATD’s before their definitive treatment.

Subjects were followed until the development of MACE, death or the database analysis was performed (October 2022 through December 2023). A MACE outcome was defined as any combination of acute heart attack, stroke, heart failure or cardiovascular death. Included in the analysis were 114,062 patients with hyperthyroidism (73.2% female, 26.8% male). Most patients were treated solely with ATD’s (93.9%). Only 1.1% (1,238 patients) received RAI and 5.1% (5,772 patients) underwent surgical removal. Over the time of follow up in the study, patients that received surgical thyroid removal (thyroidectomy) as a treatment for hyperthyroidism demonstrated a lower risk of MACE, heart failure and both cardiovascular and all-cause mortality compared to patients who received ATD’s alone. Patients who received RAI had lower risk for developing MACE in comparison to ATD-treated hyperthyroid patients. There were no differences overall in terms of risk of stroke or acute heart attack between the patient groups.

WHAT ARE THE IMPLICATIONS OF THIS STUDY?
Hyperthyroidism is associated with increased risk of cardiovascular events and overall mortality. Treatment type appears to impact this risk. Thyroidectomy was associated with lower risk of MACE and overall mortality and RAI was associated with lower risk of MACE compared to ATD’s. These findings require further confirmation but may ultimately alter the recommended treatment, particularly in patients with higher baseline risk of cardiovascular disease. Surgery or RAI may eventually be determined to be a better treatment choice for hyperthyroidism in patients with increased risk of cardiovascular disease.

— Whitney W. Woodmansee MD

Table of Contents | PDF File for Saving and Printing