Subclinical hypothyroidism is an independent predictor of adverse cardiovascular outcomes in patients with acute decompensated heart failure

Abstract

AimsAltered thyroid hormone metabolism characterized by a low triiodothyronine (T3), so‐called low‐T3 syndrome, is a common finding in patients with severe systemic diseases. Additionally, subclinical thyroid dysfunction, defined as abnormal thyroid stimulating hormone (TSH) and normal thyroxine (T4), causes left ventricular dysfunction. Our objective was to identify the prevalence and prognostic impact of low‐T3 syndrome and subclinical thyroid dysfunction in patients with acute decompensated heart failure (ADHF).Methods and resultsWe examined 274 ADHF patients who were not receiving thyroid medication or amiodarone on admission (70 ± 15 years, 156 male), who underwent thyroid function tests. Euthyroidism was defined as TSH of 0.45 to 4.49 mIU/L; subclinical hypothyroidism as TSH of 4.5 to 19.9 mIU/L; and subclinical hyperthyroidism as TSH < 0.45 mIU/L, with normal free T4 level for the last two. Additionally, low‐T3 syndrome was defined as free T3 < 4.0 pmol/L among euthyroidism subjects. On admission, 188 patients (69%) showed euthyroidism, 58 (21%) subclinical hypothyroidism, 5 (2%) subclinical hyperthyroidism, and 95 (35%) low‐T3 syndrome. Cox proportional hazards models revealed that higher TSH, but not free T3 and free T4, was independently associated with composite cardiovascular events, including cardiac death and re‐hospitalization for heart failure. Indeed, subclinical hypothyroidism was an independent predictor (hazard ratio: 2.31; 95% confidence interval: 1.44 to 3.67; P < 0.001), whereas low‐T3 syndrome and subclinical hyperthyroidism were not.ConclusionsSubclinical hypothyroidism on admission was an independent predictor of adverse cardiovascular outcomes in ADHF patients, suggesting a possible interaction between thyroid dysfunction and the pathophysiology of ADHF.

Low tri-iodothyronine syndrome improve the risk prediction of mortality in patients with acute heart failure

“…Several studies have shown that low T3 syndrome is associated independently with adverse clinical outcomes in patients with heart failure [6][7][8]10 . However, definitions of low T3 syndrome and the measurement of thyroid function among different studies varied.…”

“…Low T3 syndrome is not uncommon in patients with heart failure (10.6-34.5% of such patients) [6][7][8].…”

“…Increasing evidence suggests that low T3 syndrome is associated independently with an increased risk of adverse clinical outcomes in patients with acute heart failure (AHF) [6,8,9] and chronic heart failure [10]. Although previous studies have demonstrated the independent prognostic impact of low T3 syndrome, there is lack of study adjust for baseline N-terminal pro-brain natriuretic peptide (NT-proBNP) concentrations.…”

Модель Несприятливого Перебігу Серцевої Недостатності З Урахуванням Тиреоїдного Статусу Хворих

“…Ïåðåäáà÷àºòüñÿ, ùî äàíèé ñòàí ìîaeå áóòè àäàïòèâíèì êîìïåíñàòîðíèì ìåõàí³çìîì äëÿ çáåðåaeåííÿ ñïîaeèâàííÿ åíåð㳿 òà âåëè÷èíà çì³íè êîíöåíòðàö³¿ T 3 âàð³þº çàëåaeíî â³ä òÿaeêîñò³ çàõâîðþâàííÿ [9]. Ó [10][11][12] êðèòåð³ºì âèçíà÷åííÿ ñèíäðîìó «íèçüêîãî» òðèéîäòèðîí³íó º íèaeíÿ ìåaeà íîðìè Ò 3â ( 2,5 ïìîëü/ë) çà íîðìàëüíèõ ð³âí³â Ò 4â ³ ÒÒÃ. Ó íàøîìó äîñë³äaeåíí³ âèÿâëåíî, ùî á³ëüø çíà÷óùèì äëÿ õâîðèõ ³ç ÑÍ º ð³âåíü Ò 3â  2,07 ïìîëü/ë.…”

Forecasting the course of a heart failure in patients with a non-toxic goiter, accounting function of the thyroid gland

“…Згідно з даними японських дослідників, навіть пацієнти з I ФК СН та в стадії компенсації мають деякі ранні прояви СНТ 3 [20]. У пацієнтів з СН, даний синдром асоціюється з поганою функці-єю ЛШ, тахіаритмією та підвищенням смертності [21].…”