ATA Guidelines Updated for Managing Hyperthyroidism
Expert task force revises the 5-year old clinical care guidelines to reflect critical advances in patient management
The American Thyroid Association (ATA) updated, evidence-based recommendations to enhance guidance to clinicians in the management of patients with hyperthyroid diseases, and other forms of thyrotoxicosis.1 The section on less common causes of thyrotoxicosis was expanded in the 2016 update.
“A wealth of new clinical information has resulted in the modification of recommendations, and the addition of new concepts,"said the ATA Task Force chair, and lead author Douglas Ross, MD, who is co-director of Thyroid Associates at Massachusetts General Hospital in Boston, MA.
Thyrotoxicosis has multiple etiologies and manifestations with many potential therapies available. However, appropriate treatment requires accurate diagnosis; and, is also influenced by coexisting medical conditions and patient preferences.
New Paradigms Reflected in the Updated Guidelines
Considerable new literature that has been amassed since the original guidelines were issued in 2011, which has necessitated the addition of four new paradigms in the following areas:
- Evaluation of the etiology of thyrotoxicosis: Since the publication of the 2011 guidelines, third-generation thyrotropin receptor antibody (TRAb) assays have become widely available. The 2016 guidelines recommend that measurement of TRAb, radioactive iodine uptake (RAIU), and thyroidal blood flow on ultrasound (provided expertise is available) are all reasonable methods for determining the etiology of thyrotoxicosis. In addition, TRAb measurements have been confirmed as more cost effective, and quicker to obtain, than RAIU measurements.
- Management of Graves’ hyperthyroidism with antithyroid drugs: The updated guidelines, citing the timing of serious side effects from antithyroid drugs (ATDs) that usually occur within the first 120–180 days of treatment, state that long-term antithyroid drug therapy is reasonable for patients who prefer that approach. The current recommendation is to measure TRAb after 1–2 years of ATD therapy and either continue ATDs, or proceed with definitive therapy if TRAb is still elevated. This is a change from the former suggestion of stopping ATDs after 1–2 years of treatment to see whether the patient had attained a remission. Many clinicians had interpreted this as a recommendation to proceed with definitive therapy if a remission was not achieved in 1–2 years.
- Management of pregnant hyperthyroid patients: New data suggest that both methimazole and propylthiouracil (PTU) can cause birth defects, although PTU-associated birth defects are less severe. Previously, it had been thought that methimazole, but not PTU, caused birth defects, so the prior guidelines had recommended that clinician switch their pregnant patients to PTU in the first trimester. However, based on new data, the 2016 guidelines offer four strategies for women with hyperthyroidism who may become pregnant.
- Preparation of patients for thyroid surgery: New data suggest that repletion of calcium and vitamin D is important before a patient undergoes surgery for hyperthyroidism. The 2016 guidelines recommend that calcium and vitamin D status be assessed and/or supplemented prophylactically to reduce the incidence of post-operative hypocalcemic symptoms.
In addition to these four major changes, several other updates were made to the guidelines based on compelling new findings.
“The endocrinologist and endocrine surgeon will be able to glean key new management choices from these guidelines that influence daily patient care,” said Mira Milas, MD, FACS, who is Chief of Endocrine Surgery, Banner – University Medical Center in Phoenix, AZ. “As an endocrine surgeon, I particularly appreciate the recommendation of supplemental calcium intake prior to surgery for Graves’ disease to help avoid symptoms of hypocalcemia after surgery.”
Guidelines Include 124 Evidence-Based Recommendations
The updated guidelines present 124 evidence-based recommendations to aid clinicians in the best care of patients with thyrotoxicosis. Critical topics with notable advances in practice include:
- Initial evaluation and management of thyrotoxicosis
- Management of Graves’ hyperthyroidism using radioactive iodine, antithyroid drugs, or surgery
- Management of toxic multinodular goiter or toxic adenoma using radioactive iodine or surgery
- Graves’ disease in children, adolescents, or pregnant patients
- Subclinical hyperthyroidism
- Hyperthyroidism in patients with Graves’ orbitopathy
- Management of less common causes of thyrotoxicosis
To update the 2011 guidelines, the ATA assembled a task force of 11 experts, representing the fields of adult and pediatric endocrinology, nuclear medicine, and surgery. These task force members systematically examined the relevant literature published over the past 5 years, and incorporated the new knowledge coupled with experience into the new guidelines. The task force’s objective was to outline what they believed to be current, rational, and optimal medical practice without sacrificing the importance of clinical judgment, individual decision-making, and the wishes of the patient or the patient’s family.