Amiodarone‐induced thyrotoxicosis in heart failure with a reduced ejection fraction: A retrospective cohort study

Abstract

BackgroundAmiodarone‐induced thyrotoxicosis (AIT) is associated with significant morbidity and mortality. We aimed to describe AIT and its clinical outcomes in patients with heart failure with reduced ejection fraction (HFrEF).MethodsWe performed a retrospective chart review at a heart failure center in Winnipeg, Canada. We screened 1059 consecutive patients seen over a 12‐month period (August 2011 to July 2012) for AIT in patients with HFrEF. Using descriptive and Cox proportional hazard analyses, we explored the association between AIT and mortality.ResultsA total of 110 patients with HFrEF who were exposed to amiodarone were included in the analysis. Of these, 13 (11.8%) were diagnosed with AIT. All AIT patients in our cohort were male. Amiodarone was discontinued in nearly half (46.2%) of patients with AIT. All patients were treated with antithyroid medications, and 5 patients (38.5%) also received prednisone. Euthyroidism was achieved in 2 patients (15.4%), hypothyroidism occurred in 6 patients (46.2%), and 5 patients remained thyrotoxic until death or time of chart review (38.5%).ConclusionThyrotoxicosis is common in patients with HFrEF on amiodarone and is challenging to treat. Due to the sample size, while no association was found in mortality for patients with HFrEF with AIT, a real association could have been missed.

Management in A Patient with Cardiomyopathy and Thyrotoxicosis: A Challenging Decision

“…Differentials include Graves' disease, toxic multinodular goiter and/or amiodarone induced thyrotoxicosis (AIT). AIT is known to present after weeks to months of amiodarone consumption [3]. This patient was known to be on amiodarone as an outpatient but remains unclear if he was compliant.…”

“…Severe thyrotoxicosis can result in cardiomyopathy if left untreated due to decreased systemic vascular resistance and uncontrolled tachycardia. However, it is uncommon to see patients with known cardiomyopathy develop severe thyrotoxicosis [1][2][3][4]. There is increased mortality in hyperthyroid patients with NYHA Class II and III Heart Failure [5,6].…”

Total thyroidectomy in a patient awaiting heart transplant with amiodarone‐induced thyrotoxicosis: A case report

“…In a population of patients with HFrEF treated with amiodarone, Yamamoto et al encountered about 12% with AIT development. 17 Although uncommon, AIT is associated with three‐fold increased risk of major adverse cardiovascular events; that is why its early diagnosis and prompt treatment are crucial. 10 …”

“…In a population of patients with HFrEF treated with amiodarone, Yamamoto et al encountered about 12% with AIT development. 17 Although uncommon, AIT is associated with three-fold increased risk of major adverse cardiovascular events; that is why its early diagnosis and prompt treatment are crucial. 10 Thyroid dysfunction is a common event in amiodarone treated patients, so all patients should have TSH levels measured before starting therapy, at three-to four-month intervals during treatment and for at least 1 year after the amiodarone is discontinued.…”

Amiodarone-induced thyrotoxicosis type 2: predictors and treatment options

“…Часто развитие АмИТ2 неожиданное и бурное, в раннем периоде или через несколько лет от начала терапии Ам. Наибольшую опасность заболевание представляет у пожилых пациентов с нарушенной функцией левого желудочка, поскольку усугубляет проявления имеющейся кардиальной патологии и может приводить к летальному исходу [40]. Благодаря антиадренергической активности Ам и его блокирующему влиянию на конверсию Т 4 в Т З , классические симптомы тирео токсикоза -потливость, тремор рук, потеря веса -могут быть выражены незначительно или отсутствовать.…”