Thyroid function on admission and outcome in patients hospitalized for acute decompensated heart failure.

BACKGROUND: Although thyroid dysfunction is a known prognostic factor for cardiovascular disease, the relationship between thyroid function and prognosis in patients with acute decompensated heart failure (ADHF) is poorly understood. Herein, we investigated the association between thyroid hormone levels and outcome in patients hospitalized for ADHF.

METHODS: We evaluated 270 hospitalized ADHF patients with thyroid hormone levels measured at admission between April 2007 and May 2012.

RESULTS: The median (interquartile range) thyroid stimulating hormone, free triiodothyronine (fT3), and free thyroxine were 2.79 (1.49-4.96)μU/ml, 2.32 (1.93-2.75)pg/ml, and 14.0 (12.1-15.7)pg/dl, respectively. Receiver operating characteristic (ROC) curve analysis was applied to assess their prognostic value for in-hospital outcome. The fT3 had the most favorable performance, with an area under the ROC curve of 0.791 (optimal cutoff point ≤2.05; sensitivity 85.0%; specificity 72.0%). Although patients in the low fT3 group (≤2.05) had higher age and lower body mass index, there were no significant differences with respect to systolic blood pressure and heart rate between the groups. In multivariate analysis adjusted for various markers of disease severity and amiodarone use, low fT3 level was independently associated with higher in-hospital mortality (odds ratio 14.4; p<0.001). In addition, the probability of 1-year total death among patients with low fT3 was significantly higher than that among patients with normal fT3 (log-rank p<0.001).

CONCLUSIONS: Low fT3 level was associated with adverse outcomes in patients hospitalized for ADHF. Thyroid hormone measurements might be useful in the risk stratification of ADHF patients.