Related Experiment Videos
Prognostic impact of subclinical thyroid dysfunction in heart failure
Anna Frey1, Matthias Kroiss, Dominik Berliner
1Department of Internal Medicine I, Cardiology, University Hospital Würzburg, Germany. frey_a@medizin.uni-wuerzburg.de
International Journal of Cardiology
|October 9, 2012
Summary
Subclinical thyroid dysfunction does not increase mortality risk in heart failure (HF) patients. Euthyroid sick syndrome (ESS) in HF patients indicates a poor prognosis, but subclinical thyroid issues do not require further intervention.
Area of Science:
- Cardiology
- Endocrinology
- Internal Medicine
Background:
- The prognostic significance of subclinical thyroid dysfunction in heart failure (HF) patients remains unclear.
- This study investigated the prognostic impact of euthyroidism, subclinical thyroid dysfunction, and euthyroid sick syndrome (ESS) in systolic HF.
Purpose of the Study:
- To compare the prognostic impact of euthyroidism, subclinical thyroid dysfunction, and ESS in patients with systolic heart failure.
- To determine if subclinical thyroid dysfunction predicts mortality risk in HF patients.
Main Methods:
- Included 758 patients with systolic HF (LVEF ≤40%) from a randomized trial.
- Assessed all-cause death risk based on thyroid function tests (TSH and full profile).
- Evaluated changes in thyroid function after six months in 451 subjects.
Main Results:
- Subclinical thyroid dysfunction was present in 14% of patients at baseline.
- Euthyroid sick syndrome (ESS) was associated with a 3-fold increased age-adjusted mortality risk (P=0.001).
- Neither subclinical hyperthyroidism nor hypothyroidism predicted increased mortality risk; persistent dysfunction also showed no worse outcome.
Conclusions:
- Subclinical thyroid dysfunction does not predict increased mortality in moderate to severe HF.
- Further diagnostic and therapeutic procedures for subclinical thyroid dysfunction appear unnecessary in HF patients.
- ESS is an infrequent but significant indicator of poor prognosis in HF.
Related Concept Videos
01:27Hyperthyroidism II: Pathophysiology
Hyperthyroidism is a hypermetabolic state caused by elevated levels of thyroid hormones, triiodothyronine (T3) and thyroxine (T4). It results from dysregulation at the thyroid, pituitary, or immune system level and affects multiple organ systems.PathophysiologyThe most common cause of hyperthyroidism is Graves’ disease, an autoimmune disorder in which antibodies, specifically thyroid-stimulating antibodies (TSAb), a subtype of TSH receptor antibodies (TRAb), bind to and activate TSH receptors...
01:23Hypothyroidism II: Pathophysiology
Hypothyroidism is a disorder characterized by insufficient production of thyroid hormones, which regulate metabolism, energy balance, and multiple organ systems.TypesHypothyroidism is classified based on the level of dysfunction. Primary hypothyroidism results from intrinsic thyroid gland dysfunction, causing reduced hormone production despite normal or increased stimulation. Secondary hypothyroidism arises from inadequate thyroid-stimulating hormone (TSH) secretion by the pituitary. Tertiary...
01:27Heart Failure I: Introduction
Heart failure refers to a clinical syndrome caused by structural or functional cardiac disorders that prevent the heart from pumping an adequate amount of blood to meet the body's metabolic needs. This condition often arises from myocardial infarction or ischemia, leading to decreased cardiac output, reduced tissue perfusion, impaired gas exchange, fluid volume imbalance, and decreased functional ability.Heart failure can result from disruptions in the mechanisms that regulate cardiac output...
01:25Hyperthyroidism I: Introduction
Hyperthyroidism is a type of thyrotoxicosis characterized by the thyroid gland's overproduction of the thyroid hormones triiodothyronine (T3) and thyroxine (T4). This hormone excess increases the basal metabolic rate and enhances sensitivity to catecholamines.DiagnosisDiagnosis is based on clinical features and biochemical testing. It typically shows suppressed thyroid-stimulating hormone (TSH) levels below 0.4 mIU/L, with elevated free T3 and/or T4. Additional tests, including thyroid...
01:17Pathophysiology of Heart Failure
Heart failure (HF) is a progressive syndrome involving ventricles that leads to inadequate cardiac output. It can be classified based on location and output or ejection fraction. Ejection fraction (EF) is an essential measurement in the diagnosis and surveillance of HF. Reduced EF corresponds to systolic heart failure (HFrEF). However, HF with preserved ejection fraction (HFpEF) is becoming increasingly prevalent. Also known as diastolic HF, this form of HF is related to aging. The...
01:30Heart Failure IV: Classification and Diagnostic Evaluation
Heart failure can be classified in various ways, with the most common classifications based on physical activity limitations, disease progression, severity, and treatment strategies.The Functional Classification of Heart Failure divides patients into four categories based on physical activity limitation due to symptom burden.Class I: Patients in this class have cardiac disease but no physical activity limitations. Ordinary activities like walking, climbing stairs, or routine tasks do not cause...