Surgery, Radiotherapy for Hyperthyroidism Linked to Fewer Longterm Heart Risks

Credit: Unsplash / Piron Guillaume

Either thyroidectomy or radioactive iodine therapy for hyperthyroidism could help reduce longterm risk of cardiovascular disease versus the option to manage it medically, according to data from a recent study.

Findings from an analysis of more than 100,000 patients with newly diagnosed hyperthyroidism suggest patients treated with radioactive iodine experienced a lower risk of major adverse cardiovascular events like heart attacks, while patients treated with surgery had a reduced risk of events and even mortality versus patients who instead only received antithyroid medication.

“While there are three main treatment options for this condition, the selection of therapy needs to be individualized—this is not one-size-fits-all,” study author Elizabeth Pearce, MD, MSc, professor of Medicine at the Boston University School of Medicine, said in a statement. “Our study suggests that it may be important to consider an individual's cardiovascular risk in making decisions about hyperthyroidism treatment.”

For patients with hyperthyroidism, researchers have identified three treatment approaches with longterm benefit: antithyroid drugs, radioactive iodine therapy, and thyroidectomy. Despite these being staples in the management of patients, few studies have compared their longterm benefits and risks.

With this in mind, Pearce and a team of colleagues designed the current study to estimate these risks among patients with newly diagnosed hyperthyroidism within the Taiwan National Health Insurance Research Database. A database encompassing Taiwan’s entire 23.6-million-person population, investigators obtained data from a cohort of 114,062 patients aged 20 years or older with newly diagnosed hyperthyroidism between 2011 and 2020 for inclusion in their analyses.

The primary outcomes of interest for the study were major adverse cardiovascular events and all-cause mortality. Investigators defined major adverse cardiovascular events as a composite of acute myocardial infarction (heart attack), stroke, heart failure, and cardiovascular mortality.

For the purpose of analysis, treatment groups were determined within 18 months of diagnosis, with follow-up continuing until development of a major adverse cardiovascular event, all-cause mortality, or the end date of the database. Of note, the antithyroid drug group received antithyroid drugs only while the radioactive iodine and surgery groups could receive antithyroid drugs prior to treatment. Investigators pointed out any patients who underwent who underwent thyroid surgery without RAI was classified into the surgery group and vice versa.

The 114,062-person cohort identified for inclusion had a mean age of 44.1 years. Approximately three-fourths were female, and the mean follow-up duration was more than four years. Among the overall study cohort, 93.9 percent received antithyroid drugs, 1.1 percent received radioactive iodine, and 5.1 percent underwent thyroid surgery.

Analysis revealed those who underwent surgery had significantly lower risks than those in the antithyroid drug group for heart failure, cardiovascular mortality, and all-cause mortality.

When assessing outcomes according to patient sex, results indicated female patients treated with surgery had significantly lower risks of heart failure, cardiovascular mortality, and all-cause mortality compared to their counterparts treated with antithyroid drugs. Among male patients, surgery was associated with a reduction in the risk of all-cause mortality relative to treatment with antithyroid drugs.

Investigators called attention to multiple limitations within their study to consider when interpreting results. These included but were not limited to reliance on ICD codes, the retrospective nature of the cohort, and lack of granular clinical information, such as lifestyle habits, smoking status, and body mass index.

“These findings should be interpreted with caution owing to the retrospective, observational nature of the study design, which precludes the evaluation of causal relationships,” wrote investigators. “Further large, long-term prospective studies or randomized clinical trials comparing treatment modalities are needed to provide evidence to support patient-centered decision-making.”

An original version of this article was published on sister site HCPLive.