What to do with a patient who has thyrotoxicosis, an ejection fraction (EF) of 20 percent, and is in atrial fibrillation (AFib) with rapid ventricular response (RVR)?

From the Guidelines

For a patient with thyrotoxicosis, an ejection fraction of 20%, and atrial fibrillation with rapid ventricular response, the most appropriate initial management is to start with a beta-blocker, such as metoprolol, to control the heart rate, alongside anti-thyroid medication and heart failure therapy, and to consider anticoagulation to prevent thromboembolism, as recommended by the most recent guidelines 1. The patient's condition requires a multifaceted approach, addressing both the thyroid dysfunction and the cardiac manifestations.

• Controlling the heart rate is crucial, and according to the 2024 ESC guidelines for the management of atrial fibrillation, beta-blockers are recommended for rate control therapy in patients with any ejection fraction 1.
• Simultaneously, initiating anti-thyroid medication, such as methimazole, is essential to manage the thyrotoxicosis.
• For the severely reduced ejection fraction, adding heart failure therapy, including an ACE inhibitor (e.g., lisinopril) and carefully titrated diuretics (e.g., furosemide), is necessary.
• Anticoagulation, with a preference for direct oral anticoagulants (DOACs) over vitamin K antagonists (VKAs) unless specific conditions are met, should be considered to prevent thromboembolism, given the patient's atrial fibrillation and low ejection fraction, as per the guidelines 1.
• It is also important to avoid digoxin initially, as it may be less effective in thyrotoxicosis, and to carefully manage any potential interactions between medications. The comprehensive approach should prioritize the patient's safety, symptom reduction, and quality of life, with regular reassessments to adjust the treatment plan as necessary, following the principles outlined in the latest guidelines 1.

From the Research

Management of Thyrotoxicosis with Atrial Fibrillation and Heart Failure

• The patient's condition of thyrotoxicosis, an ejection fraction (EF) of 20 percent, and atrial fibrillation (AFib) with rapid ventricular response (RVR) requires careful management to prevent further cardiac complications 2.
• Treatment should focus on normalizing thyroid hormone levels and controlling symptoms, with medications such as beta-blockers, thionamides, and iodine-containing solutions 3.
• Beta-blockers, such as propranolol, can help control heart rate and reduce symptoms of thyrotoxicosis, but may need to be used with caution in patients with heart failure 4.
• In patients with AFib and RVR, beta-blockers may be useful in controlling heart rate, but may not be sufficient to convert the patient to a normal sinus rhythm 4.
• The use of anti-thyroid drugs, such as propylthiouracil or methimazole, may be necessary to reduce thyroid hormone production, but patients should be monitored for side effects 5.

Cardiac Complications and Treatment

• The patient's low EF and AFib with RVR increase the risk of cardiac complications, such as heart failure and thromboembolism 2, 5.
• Treatment should aim to reduce the risk of these complications, with medications such as anticoagulants and anti-arrhythmic agents, as well as close monitoring of cardiac function 2.
• In severe cases, plasmapheresis may be considered as a temporary therapeutic bridge to reduce circulating thyroid hormone levels and improve cardiac function 6, 3.

Monitoring and Follow-up

• Close monitoring of the patient's thyroid hormone levels, cardiac function, and symptoms is essential to adjust treatment and prevent further complications 2, 5.
• Regular follow-up appointments with an endocrinologist and cardiologist are necessary to ensure optimal management of the patient's condition 2, 5.