The reverse triiodothyronine and heart failure

Abstract

Objective — to investigate the effects of high levels of reversible triiodothyronine (T3r) on the course of heart failure (HF).Materials and methods. The examinations involved 221 patients with HF against the background of postinfarction cardiosclerosis. The investigations included determinations of the serum levels of thyroid stimulating hormone (TSH), free (T3 (T3fr)) and thyroxin (T4 (T4fr)), reversible T3 (T3r), echocardioscopy and study of the HF course.Results and discussions. The HF patients were divided into 2 groups according to the following criterion: the first group included 175 (79.19 %) patients with normal serum T3r (< 350 pg/ml). The second group included 46 (20.81 %) patients with a high level of this hormone ≥ 350 pg/ml. In patients with HF and with a high level of T3r II functional class (FC) by NYHA HF was 30 % more often compared to frequency in patients with normal level of the hormone (c2 = 7.711, p = 0.021); non­toxic goiter (0 vs. 8.0 %, at c2 = 3.953, p = 0.047). These patients had an increased level of granulocytes (5.3 %, p = 0.043), decreased relative levels of monocytes (7.14 %, p = 0.003); increased content of TSH (35.0 %, p = 0.001) was also found, with a concordant increase in T4fr (17.0 %, p = 0.002) and T3fr (11.7 %, p = 0.041). These patients also had a lower left ventricular ejection fraction (5.26 %, p = 0.037), a thinner interventricular sept (2.5 %, p = 0.007), increased left (2.22 %, p = 0.007) and right (at 1.86 %, p = 0.003) atrium size, compared to those values in patients with normal levels of reversible triiodothyronine. The serum T3r level had a positive relationship with the presence of atrial fibrillation (r = 0.176, p = 0.028), with a relative granulocytes’ levels (r = 0.363, p < 0.001); negative with thickness of the interventricular sept in diastole (r = –0.169, p = 0.048), with relative monocyte levels in blood (r = –0.204, p = 0.018). The model of high T3r level for HF included: FC HF (a = 0.160, p = 0.008), free T3 level (a = 0.095, p = 0.009), age of the first MI development (a = 0.012, p = 0.026).Conclusions. The increased T3r level was revealed in 20.8 % of HF patients with at hospitalization. The patients with increased T3r level had significantly increased granulocytes (by 5.3 %), decreased relative monocytes’ levels (by 7.1 %), increased TSH levels (by 35.0 %) with concordant increasing of T4fr (on 17.0 %) and T3fr (by 11.7 %). Besides, they demonstrated smaller ejection fraction of the left ventricle (5.26 %), decreased size of the left (2.22 %) and right (1.86 %) atriums. The serum T3r level had a positive correlation with the presence of atrial fibrillation (r = 0.176, p = 0.028) and relative granulocytes’ levels (r = 0.363, p < 0.001); negative correlation with the thickness of the interventricular sept in diastole (r = –0.169, p = 0.048), and with the relative blood monocytes’ levels (r = –0.204, p = 0.018). The regressive model of the high T3fr levels included the following parameters: HF FC (a = 0.160, p = 0.008), T3r level (a = 0.095, p = 0.009), and age of the first myocardial infarction (a = 0.012, p = 0.026).