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

Abstract

ObjectiveTo report cardiac outcomes after total thyroidectomy for amiodarone‐induced thyrotoxicosis according to the baseline left ventricular ejection fraction in a tertiary referral center.Study DesignRetrospective, monocentric.SettingThe tertiary health care system.MethodsPatients 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).ResultsThere 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).ConclusionThese results reinforce the idea that surgery, if chosen, should be performed quickly in patients with left ventricular ejection fraction <40%.

Short review: novel concepts in the approach to patients with amiodarone-induced thyrotoxicosis

“…The favorable result obtained when surgery was performed in this high-risk setting was ascribed to its capability to promptly restore euthyroidism with a consequent improvement in systolic function (mean LVEF 45% pre-surgery vs 50% post-surgery, p < 0.0001) [ 17 ]. This has been confirmed by other studies, particularly in patients with severe systolic dysfunction [ 54 , 56 ].…”

“…At multivariate analysis, duration of exposure to thyroid hormone excess was confirmed as a significant risk factor for mortality (HR 1.004, IQR 1.000–1.006) [ 57 ], as previously postulated by other authors [ 58 ]. The same results were recently confirmed in another study from a different country which reported a baseline LVEF < 40% and a longer time period prior to surgery as the main determinants of cardiac mortality [ 54 ].…”

“…An original series reported very high rates of complications (29.5%) and mortality (8.8%)[ 49 ], even though a more recent study on 17 AIT patients submitted to total thyroidectomy at the same hospital revised the unfavorable data previously described [ 49 ]. Importantly, subsequent reports were generally concordant in confirming the safety of surgery in this setting, when performed by a skilled team of anesthesiologists and surgeons [ 17 , 50 – 53 ]: specifically, the two largest series (totalling 102 thyroidectomies for AIT) reported complications rate ranging from 7.8% to 11.8% [ 17 , 54 ].…”

“…As anesthetic and surgical risks may remain quite high in this setting [ 59 ], a careful risk-to-benefit evaluation should be performed in the individual patient [ 60 , 61 ]. It seems agreeable to have surgery performed by skilled surgeons and only when a multidisciplinary team is available [ 17 , 53 , 54 , 62 , 63 ].…”