Nonthyroidal Illness Syndrome and Hypothyroidism in Ischemic Heart Disease Population: A Systematic Review and Meta-Analysis

The impact of thyroid disorder on cardiovascular disease: Unraveling the connection and implications for patient care

The thyroid gland is responsible for metabolism, as well as cardiac function and the peripheral vascular system. Thyroid dysfunctions are associated with an increase in the risk of cardiovascular diseases, including heart failure and coronary heart disease atrial fibrillation, by impairing heart contractility, stroke volume, heart rate, peripheral vascular resistance, and electrical activity. Thyroid dysfunctions also alter several cardiovascular risk factors, such as atherosclerosis, hypertension, and dyslipidemia, as well as causing stroke, which is associated with atrial fibrillation. An antiarrhythmic drug, amiodarone, may also induce both thyrotoxicosis and hypothyroidism, so its use requires serial thyroid function testing. Every CVD patient is recommended to be screened and treated for any possible thyroid dysfunction to reduce the patient's mortality and morbidity.

Long-term prognostic value of thyroid hormones in left ventricular noncompaction

PURPOSE

Thyroid function is closely related to the prognosis of cardiovascular diseases. This study aimed to explore the predictive value of thyroid hormones for adverse cardiovascular outcomes in left ventricular noncompaction (LVNC).

METHODS

This longitudinal cohort study enrolled 388 consecutive LVNC patients with complete thyroid function profiles and comprehensive cardiovascular assessment. Potential predictors for adverse outcomes were thoroughly evaluated.

RESULTS

Over a median follow-up of 5.22 years, primary outcome (the combination of cardiovascular mortality and heart transplantation) occurred in 98 (25.3%) patients. For secondary outcomes, 75 (19.3%) patients died and 130 (33.5%) patients experienced major adverse cardiovascular events (MACE). Multivariable Cox analysis identified that free triiodothyronine (FT3) was independently associated with both primary (HR 0.455, 95%CI 0.313-0.664) and secondary (HR 0.547, 95%CI 0.349-0.858; HR 0.663, 95%CI 0.475-0.925) outcomes. Restricted cubic spline analysis illustrated that the risk for adverse outcomes increased significantly with the decline of serum FT3. The LVNC cohort was further stratified according to tertiles of FT3 levels. Individuals with lower FT3 levels in the tertile 1 group suffered from severe cardiac dysfunction and remodeling, resulting in higher incidence of mortality and MACE (Log-rank P < 0.001). Subgroup analysis revealed that lower concentration of FT3 was linked to worse prognosis, particularly for patients with left atrial diameter ≥ 40 mm or left ventricular ejection fraction ≤ 35%. Adding FT3 to the pre-existing risk score for MACE in LVNC improved its predictive performance.

CONCLUSION

Through the long-term investigation on a large LVNC cohort, we demonstrated that low FT3 level was an independent predictor for adverse cardiovascular outcomes.

Thyroid Function in Causal Relation to MRI Markers of Cerebral Small Vessel Disease: A Mendelian Randomization Analysis

CONTEXT

Observational studies have provided insufficient information on the association between thyroid function and the risk of cerebral small vessel disease (CSVD); moreover, the causality of this link is still unclear.

OBJECTIVE

This study aims to investigate whether genetically predicted variation within thyroid function is causally associated with the risk of CSVD using 2-sample Mendelian randomization (MR) analysis.

METHODS

In this 2-sample MR study with genome-wide association variants, we estimated the causal effects of genetically predicted thyrotropin (thyroid-stimulating hormone, TSH; n = 54 288), free thyroxine (FT4; n = 49 269), hypothyroidism (n = 51 823), and hyperthyroidism (n = 51 823) on 3 neuroimaging markers of CSVD, including white matter hyperintensity (WMH; n = 42 310), mean diffusivity (MD; n = 17 467), and fractional anisotropy (FA, n = 17 663). The primary analysis was conducted by the inverse variance-weighted MR method, followed by sensitivity analyses using MR-PRESSO, MR-Egger, weighted median, and weighted mode methods.

RESULTS

Genetically increased TSH was associated with increased MD (β = .311, 95% CI 0.0763, 0.548, P = .01). Genetically increased FT4 was associated with increased FA (β = .540, 95% CI 0.222, 0.858, P < .001). Sensitivity analyses using different MR methods showed similar directions but lower precision. No significant associations of hypothyroidism or hyperthyroidism with WMH, MD, or FA were found (all P > .05).

CONCLUSION

This study indicated that genetically predicted increased TSH was associated with increased MD, as well as increased FT4 with increased FA, implying the causal effect of thyroid dysfunction on white matter microstructural injury. There were no significant causal relationships of hypothyroidism or hyperthyroidism with CSVD. Further investigations should verify these findings and clarify the underlying pathophysiological mechanisms.

The severity of valvular heart disease in euthyroid individuals is associated with thyroid hormone levels but not with TSH levels

Background

Abnormal thyroid function is a metabolic disorder and can lead to several complications, including cardiovascular diseases. In this study, we aimed to examine the relationship between clinical traits and outcomes and the thyroid hormone level of euthyroid individuals with valvular heart disease (VHD).

Method

The thyroid function was evaluated in 526 euthyroid VHD patients and 155 healthy control people. As well as clinical indicators were collected and analyzed.

Results

No difference in TSH levels (p>0.05) was recorded; however, fT3, TT3, and TT4 levels were lower in the euthyroid VHD patients than in healthy control(4.3 vs 4.63; 1.37 vs 1.48; 97.7 vs 102.09, respectively, all p<0.05), while the fT4 level was higher (12.91 vs 12.35, p<0.05). Moreover, all showed a continuous trend with the change of NYHA grade which does not consist of the incidence of euthyroid sick syndrome(ESS). Further analysis showed that for every 10-fold increase in BNP, fT4 increases by 83%, fT3 decreases by 30%, and TT3 decreases by 12% after being adjusted for other influencing factors. Meanwhile, adjusted fT4 was correlated with multiple worse clinical indicators, which were influenced by age.

Conclusion

Thyroid hormones are widely regulated in VHD patients even with acceptable cardiac function, except for TSH level. And the adjusted fT4 is related to worse clinical indicators and outcomes which are only recorded in patients under 53 years old.

Similar hypothyroid and sepsis circulating mRNA expression could be useful as a biomarker in nonthyroidal illness syndrome: a pilot study

Objective

Based on hypothetical hypothyroidism and nonthyroidal illness syndrome (NTIS) gene expression similarities, we decided to compare the patterns of expression of both as models of NTIS. The concordant profile between them may enlighten new biomarkers for NTIS challenging scenarios.

Materials and methods

We used Ion Proton System next-generation sequencing to build the hypothyroidism transcriptome. We selected two databanks in GEO2 platform datasets to find the differentially expressed genes (DEGs) in adults and children with sepsis. The ROC curve was constructed to calculate the area under the curve (AUC). The AUC, chi-square, sensitivity, specificity, accuracy, kappa and likelihood were calculated. We performed Cox regression and Kaplan-Meier analyses for the survival analysis.

Results

Concerning hypothyroidism DEGs, 70.42% were shared with sepsis survivors and 61.94% with sepsis nonsurvivors. Some of them were mitochondrial gene types (mitGenes), and 95 and 88 were related to sepsis survivors and nonsurvivors, respectively. BLOC1S1, ROMO1, SLIRP and TIMM8B mitGenes showed the capability to distinguish sepsis survivors and nonsurvivors.

Conclusion

We matched our hypothyroidism DEGs with those in adults and children with sepsis. Additionally, we observed different patterns of hypothyroid-related genes among sepsis survivors and nonsurvivors. Finally, we demonstrated that ROMO1, SLIRP and TIMM8B could be predictive biomarkers in children´s sepsis.

Interplay between cardiovascular and thyroid dysfunctions: A review of clinical implications and management strategies

Cardiovascular diseases (CVD) and thyroid dysfunction are two of the most prevailing disorders in the world that are closely interlinked. Actions of thyroid hormones are mediated via thyroid receptors present in the myocardium and the vascular tissue. Primary mechanism that links thyroid dysfunction with CVD is the modification of cardiovascular risk factors (dyslipidemia, blood pressure, coagulation parameters, etc.) resulting in endothelial and left ventricular systolic and diastolic dysfunction.

Both overt and subclinical hyperthyroidism and hypothyroidism may cause adverse alterations in cardiac function. Hyperthyroidism gives rise to palpitation, atrial fibrillation, systolic hypertension, and heart failure, whereas hypothyroidism increases diastolic hypertension, pericardial effusion, and the risk of ischemic heart disease via altering lipid and coagulation parameters. Early recognition and treatment of thyroid dysfunction may prevent adverse cardiovascular events in patients with or without pre-existing CVD.

Certain cardiac conditions and medications can cause alterations in thyroid function that may predispose an individual to higher morbidity and mortality. In certain situations, thyroid dysfunction treatment may have cardiovascular benefits. This study deals with the interplay between cardiovascular and thyroid dysfunctions associated with clinical implications and management strategies.

Minor perturbations of thyroid homeostasis and major cardiovascular endpoints—Physiological mechanisms and clinical evidence

It is well established that thyroid dysfunction is linked to an increased risk of cardiovascular morbidity and mortality. The pleiotropic action of thyroid hormones strongly impacts the cardiovascular system and affects both the generation of the normal heart rhythm and arrhythmia. A meta-analysis of published evidence suggests a positive association of FT4 concentration with major adverse cardiovascular end points (MACE), but this association only partially extends to TSH. The risk for cardiovascular death is increased in both subclinical hypothyroidism and subclinical thyrotoxicosis. Several published studies found associations of TSH and FT4 concentrations, respectively, with major cardiovascular endpoints. Both reduced and elevated TSH concentrations predict the cardiovascular risk, and this association extends to TSH gradients within the reference range. Likewise, increased FT4 concentrations, but high-normal FT4 within its reference range as well, herald a poor outcome. These observations translate to a monotonic and sensitive effect of FT4 and a U-shaped relationship between TSH and cardiovascular risk. Up to now, the pathophysiological mechanism of this complex pattern of association is poorly understood. Integrating the available evidence suggests a dual etiology of elevated FT4 concentration, comprising both ensuing primary hypothyroidism and a raised set point of thyroid function, e. g. in the context of psychiatric disease, chronic stress and type 2 allostatic load. Addressing the association between thyroid homeostasis and cardiovascular diseases from a systems perspective could pave the way to new directions of research and a more personalized approach to the treatment of patients with cardiovascular risk.

Nonthyroidal illness syndrome in acute pancreatitis patients: an 8-year cohort study

BACKGROUND

Nonthyroidal illness syndrome (NTIS) is common in critical illness and is associated with poor prognosis. The aim of this study was to find the prevalence, charateristics, and prognosis of NTIS and its correlation with outcomes in AP patients.

METHODS

A retrospective review of AP patients with a diagnosis of NTIS from Jan 2012 to September 2020 was performed. The serum thyroidal hormone (TH) disturbances, as well as the demographic characteristics and clinical outcomes of the study patients, were collected and analyzed.

RESULTS

Over the eight years, 183 included AP patients were diagnosed as NTIS, constituting an incidence of 64.7%. Patients with NTIS were admitted with worse condition based on the higher APACHE II score, SOFA score, Balthazar's CT score, CRP and lower albumin than euthyroid patients. Also, these patients had a longer ICU duration (3, 2-10 vs 2, 0-3, days, P = 0.039) and tended to be more likely to develop infected pancreatic necrosis (IPN) (15.3% vs 6.3%, P = 0.087) and gastrointestinal fistula (6% vs 0%, P = 0.082) than euthyroid patients. Free triiodothyronine (FT3) was found the best performance in predicting death compared by other well-recognized biomarkers.

CONCLUSION

NTIS is common in AP patients within 7 days after the onset of the disease. NTIS is associated with the worse characteristics at admission and poor outcome during the course. FT3 should be investigate as a potential biomarker in the prediction of death in AP patients.

Thyroid and heart, a clinically relevant relationship

BACKGROUND

Thyroid disorders, both overt and subclinical, are highly prevalent conditions in the general population. Although a clear relationship between overt thyroid dysfunctions and cardiovascular complications has long been established, data regarding subclinical thyroid dysfunction are by far more controversial.

PURPOSE

The present review will be aimed at providing a summary of most recent evidence coming from meta-analyses regarding the complex relationship between thyroid dysfunction and cardiovascular disease.

CONCLUSIONS

The review will summarize, in the first part, the physiopathological link between thyroid hormone imbalances and the cardiovascular system. In the second part the review will outline the evidence coming from meta-analyses regarding the cardiovascular risk related with both overt and subclinical thyroid dysfunctions. Particular attention will be put towards studies showing data stratified for patient's age, TSH levels and pre-existing cardiovascular disease. Finally, an overview regarding the effects of specific therapy for subclinical thyroid diseases in terms of amelioration of cardiovascular outcomes will be included.

The prognostic impact of thyroid disorders on the clinical severity of COVID-19: Results of single-centre pandemic hospital

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can cause thyroid hormonal disorders. In addition, tracheal compression by thyroid nodules can aggravate hypoxia in critically ill patients. No studies have investigated the effect of thyroid nodules on the prognosis of patients with COVID-19. In this study, we investigated the effect of thyroid hormonal disorders and thyroid nodules on the prognosis of patients with COVID-19.

MATERIALS AND METHODS

This prospective study was conducted at the Şırnak State Hospital (Pandemic hospital in Turkey) between 15 March and 15 August 2020. We evaluated thyroid hormonal disorder and thyroid nodules in 125 patients who were admitted to the non-intensive care unit (non-ICU) due to mild COVID-19 pneumonia (group 1) and 125 critically ill patients who were admitted to the ICU (group 2).

RESULTS

Thyroid-stimulating hormone levels (TSH) were not significantly different between groups 1 and 2; however, group 2 patients had significantly lower levels of free thyroxine (FT4) and free triiodothyronine (FT3) as compared to group 1 (P = .005, P < .0001, respectively). FT3 level showed a negative correlation with length of hospital stay and C-reactive protein level (rho: -0.216, p: 0.001; rho: -0.383, P < .0001). Overt thyroid disorder was observed in 13 patients [2 patients in group 1 (both with overt thyrotoxicosis) and 11 patients in group 2 (3 overt hypothyroidism, 8 overt thyrotoxicosis) (P = .01)]. Thyroid nodules sized ≥1 cm were found in 9 patients (7%) in group 1 and 32 patients (26%) in group 2 (P < .0001).

CONCLUSION

Overt thyroid hormonal disorders were more common in critically ill COVID-19 patients. FT3 level at hospital admission is a potential prognostic marker of COVID-19 patients. Thyroid nodules may be associated with severe COVID-19 disease.

Thyroid Dysfunction in Patients Admitted in Cardiac Care Unit: Prevalence, Characteristic and Hospitalization Outcomes

Introduction

Cardiovascular disease is one of the main causes of hospital admission and mortality, and thyroid dysfunction increases the risk of developing acute or exacerbation of chronic cardiac conditions. The aim of this study is to investigate the prevalence of thyroid hormone abnormality among patients in the cardiac care unit (CCU) patients and its relation to admission diagnosis, clinical, biochemical data, and hospital-related outcomes.

Methods

We conducted a retrospective cohort observational that included adult patients who were admitted to the CCU. We excluded those with known thyroid dysfunction and those who received amiodarone or IV contrast.

Results

A total of 374 patients with a mean age of 62.7+14.7 years old were included. Ischemic changes were observed in 70.6% of the patients based on the admission diagnosis. In comparison to the non-ischemic group, the ischemic group was more likely to be male (P=0.010), to be active/former smokers (P=0.011), to have diabetes (P=0.009), to have diastolic dysfunction (P=<0.001), to have undergone thrombolysis (P=<0.001), and to have been referred to a tertiary center (P=<0.001). Euthyroidism was observed in 57.8% of the patients based on the thyroid function test at admission. Compared to patients with thyroid dysfunction, those with Euthyroidism were more likely to be active/former smokers (P=0.002), to have lower heart rates (P=0.018), to not have chronic kidney disease (P=0.016), to not have heart failure (P=0.006), to have lower thyroid-stimulating hormone (TSH) levels (P=<0.001), and to have lower tricuspid regurgitation (P=0.042).

Conclusion

Thyroid dysfunction is common among patients admitted to the CCU. Non-significant positive correlations between TSH and hospitalization length, tertiary center referral, 30-day readmission, and in-hospital mortality when adjusting for potential confounders.