Mortality After Total Thyroidectomy for Amiodarone‐Induced Thyrotoxicosis According to Left Ventricular Ejection Fraction

Abstract Objective To report cardiac outcomes after total thyroidectomy for amiodarone‐induced thyrotoxicosis according to the baseline left ventricular ejection fraction in a tertiary referral center. Study Design Retrospective, monocentric. Setting The tertiary health care system. Methods Patients who underwent total thyroidectomy for amiodarone‐induced thyrotoxicosis between 2010 and 2020 with age >18 and available preoperative left ventricular ejection fraction were included in this study. Patients were dichotomized into: group 1 with left ventricular ejection fraction ≥40% (mildly reduced/normal ejection fraction), and group 2 with left ventricular ejection fraction <40% (reduced ejection fraction). Results There were 34 patients in group 1 and 17 to group 2. The latter were younger (median 58.4 [Q1‐Q3 48.0‐64.9] vs. 69.8 years in group 1 [59.8‐78.3], p = .0035) and they presented more cardiomyopathy (58.8 vs. 26.5%, p = .030). Overall, the median time until surgery referral was 3.1 [1.9‐7.1] months and 47.1% underwent surgery after restoration of euthyroidism. Surgical complications accounted for 7.8%. In group 2, the median left ventricular ejection fraction was significantly improved after surgery (22.5 [20.0‐25.0] vs. 29.0% [25.3‐45.5], p = .0078). Five‐year cardiac mortality was significantly higher in group 2 ( p < .0001): 47.0% died of cardiac causes versus 2.9% in group 1. A baseline left ventricular ejection fraction <40% and a longer time until surgery referral were significantly associated with cardiac mortality (multivariable Cox regression analysis, p = .015 and .020, respectively). Conclusion These results reinforce the idea that surgery, if chosen, should be performed quickly in patients with left ventricular ejection fraction <40%.