Pulmonary hypertension in thyroid diseases

Severe pulmonary hypertension associated with hypothyroidism and mixed aortic valve disease: A case report

Pulmonary hypertension is a condition characterised by elevated pulmonary arterial pressures secondary to various aetiologies; the most common ones are left heart diseases. Similarly, an association between thyroid diseases and pulmonary hypertension has been reported in some cases, but the pathophysiological relationship has not been fully elucidated. Etiological investigation is an important step in the management of pulmonary hypertension and determines the appropriate treatment. In this report, we present a case of severe pulmonary hypertension in a 57-year-old woman, in which mixed aortic valve disease and hypothyroidism were involved.

Prevalence and Prognosis of Hypothyroidism in Patients With Chronic Thromboembolic Pulmonary Hypertension: An Updated Review With Description of Case Series

Hypothyroidism has been shown to have several effects on organs, including derangements in the coagulation system, impairing endothelial function, but data on the importance of hypothyroidism in the pathogenesis and development of chronic thromboembolic pulmonary hypertension (CTEPH) are limited. This report presents an updated review of the prevalence and prognosis of hypothyroidism in patients diagnosed with CTEPH, including a detailed retrospective description of the series. The descriptive case series included 34 adult patients diagnosed with CTEPH, of whom 11 patients were diagnosed with hypothyroidism. The prevalence of hypothyroidism in CTEPH was found to be 32.35%. All patients with hypothyroidism had NYHA functional Class II-III. Hemodynamic values obtained through right heart catheterization (RHC) showed that patients with hypothyroidism had significantly higher mean pulmonary arterial pressures (mPAP), with a mean of 56.91 mm Hg vs 43.93 mm Hg (p = 0.026), and the PVR in dynes/sec/cm5 was 932 vs 541 (p = 0.027). Significant differences in PVR were found in wood units (WU) 11.91 vs 7.11 (p = 0.042). The mean level of brain natriuretic peptide (BNP) between both groups was 797.3 pg/mL for patients with hypothyroidism vs 262.02 pg/mL in patients with euthyroidism (p = .032). Hypothyroidism may significantly affect patients' clinical and hemodynamic outcomes in patients with CTEPH. Hypothyroidism as a risk factor in the evaluation and treatment of these patients is vital to optimize outcomes in CTEPH; further research is warranted whether hypothyroidism therapies could alter such outcomes.

Clinical features and long-term survival in idiopathic pulmonary arterial hypertension with thyroid dysfunction: insights from a national multicentre prospective study

Background

Our objective was to clarify the characteristics and long-term survival of idiopathic pulmonary arterial hypertension (IPAH) patients with thyroid dysfunction and compare them with IPAH without thyroid dysfunction.

Methods

A retrospective analysis was conducted using prospectively collected data. IPAH patients with thyroid dysfunction at baseline were included. Patients with other subgroups of PAH and Group 2-5 pulmonary hypertension were excluded. IPAH patients with euthyroid function were matched 1:1 to IPAH patients with thyroid dysfunction by age and sex.

Results

In total, 148 IPAH patients with thyroid dysfunction were included. Patients with hyperthyroidism, hypothyroidism, subclinical hyperthyroidism and subclinical hypothyroidism accounted for 16.2%, 18.9%, 8.1% and 56.8%, respectively. IPAH patients with hyperthyroidism showed the highest mixed venous oxygen saturation (SvO2) and the lowest pulmonary vascular resistance (PVR) at baseline among subgroups, while patients with subclinical hypothyroidism had the lowest SvO2 and highest PVR (p<0.05). Compared with IPAH without thyroid dysfunction, patients with hyperthyroidism (9.14 versus 13.86 WU; p<0.05) and hypothyroidism (10.70 versus 13.86 WU; p<0.05) showed significantly lower PVR. The haemodynamic profiles of patients with subclinical hypothyroidism were similar to IPAH with euthyroid function except for lower right atrial pressure (6 versus 8 mmHg; p=0.009). The long-term survival of patients with clinical thyroid dysfunction was better than IPAH without thyroid dysfunction, while that of those with subclinical diseases was comparable to the latter, even after adjusting for baseline haemodynamics and treatment.

Conclusion

IPAH patients with clinical hyper- and hypothyroidism had better haemodynamics and survival than those without thyroid dysfunction, while patients with subclinical hypothyroidism had similar haemodynamics and survival profiles to the latter.

No evidence of pulmonary hypertension revealed in an echographic evaluation of right-sided hemodynamics in hyperthyroid cats

OBJECTIVES

Hyperthyroidism is a common endocrinopathy affecting middle-aged to elderly cats, with multisystemic repercussions. Hyperthyroid humans show decreased lung compliance and increased cardiac output with subsequent left heart failure leading to pulmonary capillary congestion. Prognosis worsens with the development of increased pulmonary vascular pressures (ie, pulmonary hypertension [PH]) in hyperthyroid humans. The effect of excess thyroid hormone concentration on pulmonary arterial hemodynamics is unknown in cats. Assessing pulmonary vascular pressures in veterinary medicine relies heavily on echocardiographic measurements performed at the level of the heart and pulmonary trunk. This study investigated right-sided cardiac and pulmonary arterial hemodynamics in hyperthyroid cats using echocardiography.

METHODS

Echocardiographic examinations of hyperthyroid cats identified through a bi-institutional database search were reviewed for the determination of systolic pulmonary arterial pressure (PAP) and 20 other metrics. Values were compared with those of a healthy cat group using non-parametric statistical analyses.

RESULTS

Systolic PAP could not be determined in 23/26 hyperthyroid and 13/14 healthy cats owing to unmeasurable tricuspid regurgitation flow velocity. Hyperthyroid cats were roughly twice as old (P <0.001) and had 2-4-fold higher respiratory rates (P <0.001) than healthy cats. Hyperthyroid cats showed an increase in acceleration time-to-ejection time ratio of pulmonary flow (1.4-fold, P = 0.001), pulmonary artery velocity time integral (1.2-1.6-fold, P = 0.001), maximal pulmonary velocity (1.3-1.7-fold, P = 0.002), stroke volume (1.5-fold, P = 0.001) and cardiac output (1.6-fold, P <0.001) vs healthy cats. None of the other echocardiographic metrics reached statistical significance.

CONCLUSIONS AND RELEVANCE

Systolic PAP estimation proved unsuitable as a sole measurement for the assessment of PH in hyperthyroid cats owing to the frequent inability to interrogate tricuspid regurgitant flow velocity. Hyperthyroid cats have altered echocardiographic measures of pulmonary hemodynamics dissimilar to those reported in hyperthyroid humans. Differential effects of thyrotoxic cardiomyopathy on ventricular systolic function may underlie species differences.

Symptomatic and severe pulmonary hypertension due to hyperthyroidism

Hyperthyroidism has been recognised as the cause of secondary pulmonary hypertension (PH). However, several studies have reported that most PH cases due to hyperthyroidism are asymptomatic and not severe. Here, we report the case of a woman in her 30s with symptomatic and severe PH due to hyperthyroidism. She presented with a 2-month history of dyspnoea on exertion, palpitation and lower-extremity oedema. Echocardiography showed severe PH with estimated pulmonary arterial systolic pressure (ePASP) of 62 mm Hg. The diagnostic work-up showed severe PH due to hyperthyroidism. After treatment for hyperthyroidism, improvement of thyroid function contributed to a decrease in ePASP to 30 mm Hg. Similar to the present case, PH due to hyperthyroidism generally improves with the treatment of hyperthyroidism. Therefore, we must not overlook hyperthyroidism as a cause of PH and diagnose and start treatment for PH-causing hyperthyroidism at an early stage.

The clinical characteristics and outcomes of patients with pulmonary hypertension in association with hyperthyroid state: A systematic review

BACKGROUND

Pulmonary hypertension (PHTN) may occur in thyroid disorders, especially in hypothyroidism. However, there is increasing evidence of PHTN in hyperthyroidism (HTH). The etiology, clinical course, management, and factors associated with outcomes of PHTN in the setting of HTH are unascertained. This systematic review consolidates available evidence on patients with HTH who developed PHTN.

METHODS

We conducted a systematic review on English articles from PubMed, Scopus, and Google Scholar reporting PHTN in patients with hyperthyroidism. Data were analyzed and reported in Microsoft Excel 2020, SPSS version 26, and Jamovi version 1.2.

RESULTS

We identified 589 patients with PHTN in the setting of HTH. Etiologies included Grave disease 66.7%), toxic multinodular goiter (TMNG) (16.8%), drug-induced HTH (0.3%), thyroiditis(0.8%), and toxic adenoma(0.1%). Most patients did not receive any specific management for PHTN and were managed by antithyroid treatment (97.4%). Outcomes of PHTN were reported in 181 patients, with a 94% recovery rate. Pulmonary artery pressures (PAP) before and after HTH management ranged from 22.5 to 75 mm Hg and from 24 to 50 mm Hg, respectively. Outcome analysis performed on data from case reports and series with individually identifiable data revealed a 67.6% female preponderance. An estimated 73.5% of the patients had PHTN at the initial presentation of HTH, which was associated with a better resolution rate of PHTN(OR: 12, P-value: 0.048). TRAB was positive in 47% patients with no clinical difference in outcomes. antiTG AB was reported positive in 29.4%, all of whom had an improvement, compared to an 83.3% improvement rate in those with negative antiTG AB. Various etiologies and treatments did not have any significant differences in the outcome of PHTN.

CONCLUSIONS

PHTN can be present at the initial diagnosis of HTH, which is associated with better outcomes of PHTN. There is a clear female preponderance in the development of PHTN. However, resolution rates seem to be better in males. Although TRAB is associated with the development of PHTN, it does not seem to affect the outcomes. PHTN in patients with HTH does not need any specific management, with >90% resolution with antithyroid therapy. Whether any specific antithyroid therapy has a better outcome in PHTN needs to be explored prospectively.

Assessment of causal direction between thyroid function and cardiometabolic health: a Mendelian randomization study

BACKGROUND

Growing evidence have demonstrated that thyroid hormones have been involved in the processes of cardiovascular metabolism. However, the causal relationship of thyroid function and cardiometabolic health remains partly unknown.

METHODS

The Mendelian randomization (MR) was used to test genetic, potentially causal relationships between instrumental variables and cardiometabolic traits. Genetic variants of free thyroxine (FT4) and thyrotropin (TSH) levels within the reference range were used as instrumental variables. Data for genetic associations with cardiometabolic diseases were acquired from the genome-wide association studies of the FinnGen, CARDIoGRAM and CARDIoGRAMplusC4D, CHARGE, and MEGASTROKE. This study was conducted using summary statistic data from large, previously described cohorts. Association between thyroid function and essential hypertension (EHTN), secondary hypertension (SHTN), hyperlipidemia (HPL), type 2 diabetes mellitus (T2DM), ischemic heart disease (IHD), myocardial infarction (MI), heart failure (HF), pulmonary heart disease (PHD), stroke, and non-rheumatic valve disease (NRVD) were examined.

RESULTS

Genetically predicted FT4 levels were associated with SHTN (odds ratio = 0.48; 95% CI = 0.04−0.82,P = 0.027), HPL (odds ratio = 0.67; 95% CI = 0.18−0.88,P = 0.023), T2DM (odds ratio = 0.80; 95% CI = 0.42−0.86,P = 0.005), IHD (odds ratio = 0.85; 95% CI = 0.49−0.98,P = 0.039), NRVD (odds ratio = 0.75; 95% CI = 0.27−0.97,P = 0.039). Additionally, genetically predicted TSH levels were associated with HF (odds ratio = 0.82; 95% CI = 0.68−0.99,P = 0.042), PHD (odds ratio = 0.75; 95% CI = 0.32−0.82,P = 0.006), stroke (odds ratio = 0.95; 95% CI = 0.81−0.97,P = 0.007). However, genetically predicted thyroid function traits were not associated with EHTN and MI.

CONCLUSIONS

Our study suggests FT4 and TSH are associated with cardiometabolic diseases, underscoring the importance of the pituitary-thyroid-cardiac axis in cardiometabolic health susceptibility.

Atypical presentation of cardiac tamponade in pulmonary hypertension: A case report and review of the literature

A young woman with systemic sclerosis, hypothyroidism, and pulmonary hypertension was admitted to our center with massive pericardial effusion and left ventricular collapse. Despite undergoing successful pericardiocentesis, she passed away a month later. The best therapeutic approach in this situation remains to be determined.

Impaired endothelium-dependent and endothelium-independent systemic vasodilatory reserve in pulmonary hypertension regardless the clinical group: A generalized dysfunction beyond the pulmonary arteries?

OBJECTIVE

Endothelium-dependent (ED) and endothelium-independent (EI) flow-mediated vasodilatation (FMD) have been used as measures of systemic arterial vasodilatory reserve. In this study, we aimed to assess both ED-FMD and EI-FMD in different groups with pulmonary hypertension (PH), and to investigate the relationship of these measures with clinical, echocardiographic, and invasive parameters of diseases severity and targeted treatment status.

METHODS

Our study population comprised 41 patients with PH [28 (68.2%) women, age 46.3±19.6 years] including idiopathic pulmonary arterial hypertension, Eisenmenger syndrome, and chronic thromboembolic PH in whom diagnosis were confirmed in accordance with current guidelines and 17 age and sex-matched healthy controls. The brachial artery (BA) was used for assessment of FMD with Duplex ultrasound, and serial changes in diameter were recorded at baseline, 1, and 3 minutes after termination of 2-minute external occlusive compression for ED-FMD, and after sublingual intake of glycerol trinitrate for EI-FMD, respectively.

RESULTS

Compared with controls, overall the PH group showed significantly lower ED-FMD (0.65±0.21 vs. 0.30±0.23 and 0.65±0.18 vs. 0.24±0.21) and EI-FMD (0.67±0.15 vs. 0.37±0.25 and 0.75±0.20 vs. 0.32±0.24) responses at 1st and 3rd min (p<0.001 for all). All these changes in the values of ED-FMD and EI-FMD were comparable among the PH subgroups. Neither ED-FMD nor EI-FMD were correlated with measures of PH severity and targeted therapy (TT) status (p>0.05).

CONCLUSION

Our results suggest an impaired BA vasodilatory reserve in patients with PH regardless of the clinical subgroup. Although these findings seem to be consistent with systemic dysfunction, acute FMD may not reflect the severity of PH and cannot be used as a potential surrogate for outcome in this setting.

Impaired endothelium-dependent and endothelium-independent systemic vasodilatory reserve in pulmonary hypertension regardless the clinical group: A generalized dysfunction beyond the pulmonary arteries?

OBJECTIVE

Endothelium-dependent (ED) and endothelium-independent (EI) flow-mediated vasodilatation (FMD) have been used as measures of systemic arterial vasodilatory reserve. In this study, we aimed to assess both ED-FMD and EI-FMD in different groups with pulmonary hypertension (PH), and to investigate the relationship of these measures with clinical, echocardiographic, and invasive parameters of diseases severity and targeted treatment status.

METHODS

Our study population comprised 41 patients with PH [28 (68.2%) women, age 46.3±19.6 years] including idiopathic pulmonary arterial hypertension, Eisenmenger syndrome, and chronic thromboembolic PH in whom diagnosis were confirmed in accordance with current guidelines and 17 age and sex-matched healthy controls. The brachial artery (BA) was used for assessment of FMD with Duplex ultrasound, and serial changes in diameter were recorded at baseline, 1, and 3 minutes after termination of 2-minute external occlusive compression for ED-FMD, and after sublingual intake of glycerol trinitrate for EI-FMD, respectively.

RESULTS

Compared with controls, overall the PH group showed significantly lower ED-FMD (0.65±0.21 vs. 0.30±0.23 and 0.65±0.18 vs. 0.24±0.21) and EI-FMD (0.67±0.15 vs. 0.37±0.25 and 0.75±0.20 vs. 0.32±0.24) responses at 1st and 3rd min (p<0.001 for all). All these changes in the values of ED-FMD and EI-FMD were comparable among the PH subgroups. Neither ED-FMD nor EI-FMD were correlated with measures of PH severity and targeted therapy (TT) status (p>0.05).

CONCLUSION

Our results suggest an impaired BA vasodilatory reserve in patients with PH regardless of the clinical subgroup. Although these findings seem to be consistent with systemic dysfunction, acute FMD may not reflect the severity of PH and cannot be used as a potential surrogate for outcome in this setting.

Changes in the expression of cardiac genes responsive to thyroid hormones in the chickens with cold-induced pulmonary hypertension

Cold stress is an environmental cause of pulmonary hypertension syndrome (PHS) in broiler chickens. This factor could increase the rate of metabolic activity via thyroid hormones (T3 and T4). To evaluate the effect of these hormones on the heart, the plasma concentration of T3, T4, and the gene expression of their receptors (THRα and THRβ) and many contractile proteins (ACTC1, MHCα, MHCβ, RYR2, SERCA2, THRα, THRβ, and troponin I) were measured in the right ventricle in 2 periods of age (21 and 35 d). Plasma T3 concentration was significantly higher in the PHS group of chickens than in the control one at 21 and 35 d while plasma T4 did not change. The relative expression of MHCα, RYR2, SERCA2, and THRα genes in the right ventricle tissues was only higher in PHS group of broilers than control group at 21 d (P < 0.05) whereas the expression of ACTC1, MHCβ, and troponin I did not differ at 2 periods of age. The positive correlations between MHCα, RYR2, SERCA2, and T3, THRα were confirmed. The expression of THRβ gene was only higher in PHS group of broilers than control at 35 d (P < 0.05). The data determined that cold stress could increase thyroid hormones and the gene expression of their receptor (THRα) in the pick of chicken growth (21 d) that they themselves elevates the expression of many genes related to contractile elements (MHCα, RYR2, and SERCA2), leading to adaptive right ventricle hypertrophy.

Characteristics and Risk Factors of Pulmonary Hypertension in Patients With Hyperthyroidism

OBJECTIVE

This study aimed to comprehensively assess the characteristics and risk factors of hyperthyroidism with pulmonary hypertension (PH).

METHODS

This was a retrospective cross-sectional analysis of 315 consecutive patients with hyperthyroidism admitted to the endocrinology department of Tongji Hospital from February 2016 to December 2017. PH was defined as a pulmonary arterial systolic pressure above 35 mm Hg measured by echocardiography.

RESULTS

Among the 315 patients, 208 were females, the median age was 42 (30-51) years, and the median disease duration was 12 (3-48) months. Thirty-five percent (111/315) of patients were identified with PH. Patients with hyperthyroidism and PH showed significantly higher serum concentrations of free thyroxine (FT4), free triiodothyronine, thyroid receptor antibodies, total bilirubin (TB), direct and indirect bilirubin, lower serum levels of hemoglobin and creatinine, and more severe cardiac load (P < .05 for each) compared with patients without PH. Levels of serum FT4, free triiodothyronine, thyroid receptor antibodies, and thyroid peroxidase antibody were different among groups of patients with different levels of pulmonary arterial systolic pressure (P < .05 for each). Multivariate logistic regression analysis indicated that serum FT4 (odds ratio, 1.02; 95% CI, 1.01-1.04; P = .004) and TB (OR, 1.03; 95% CI, 1.00-1.06; P = .030) were independent risk factors for PH in patients with hyperthyroidism.

CONCLUSION

Elevated serum FT4 and TB levels may be independent risk factors for PH in patients with hyperthyroidism and valuable indicators for the identification and treatment of patients with PH and hyperthyroidism.

Factors Associated with Incident Severe Pulmonary Arterial Hypertension in Systemic Autoimmune Rheumatic Diseases: a Nationwide Study

OBJECTIVES

To assess the association of severe pulmonary arterial hypertension (PAH) with particulate matter <2.5 μm (PM2.5) and clinical data in patients with systemic autoimmune rheumatic diseases (SARDs).

METHODS

We used the 2003-2017 nationwide data in Taiwan to identify patients with SARDs, including systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, dermatomyositis/polymyositis and primary Sjögren's syndrome. We identified 479 cases with severe PAH and selected controls matched (1:4) for age, sex, and index-year. We used conditional logistic regression analysis to determine factors associated with risks for severe PAH shown as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

We found that severe PAH was highly associated with interstitial lung disease (OR, 8.57; 95% CI, 5.52-13.32), congestive heart failure (OR, 7.62; 95% CI, 5.02-11.55), valvular heart disease (OR, 3.34; 95% CI, 2.03-5.50) and slightly associated with thyroid diseases (OR, 1.88; 95% CI, 1.18-3.00), but not the level of exposure to PM2.5. Increased risk for PAH was found in patients receiving corticosteroid (prednisolone equivalent dosage, mg/day, OR, 1.03; 95% CI, 1.01-1.05), biologics (OR, 2.18; 95% CI, 1.15-4.12) as well as immunosuppressants, including cyclosporin (OR, 2.17; 95% CI, 1.31-3.59), azathioprine (OR, 1.96; 95% CI, 1.48-2.61), cyclophosphamide (OR, 2.01; 95% CI, 1.30-3.11) and mycophenolate mofetil/mycophenolic acid (OR, 2.42; 95% CI, 1.37-4.27), and those with the highest level of insured amount (reference, lowest level; OR, 0.53; 95% CI, 0.34-0.83).

CONCLUSION

The population-based study identified risks for severe PAH in patients with SARDs, and these findings provide evidence for PAH risk stratification in patients with SARDs.

Interplay Between Thyroid Hormone Status and Pulmonary Hypertension in Graves' Disease: Relevance of the Assessment in Thyrotoxic and Euthyroid Patients

BACKGROUND

Graves' disease (GD) is the most common cause of hyperthyroidism and can cause cardiac changes, such as pulmonary hypertension.

METHODS

This is a prospective study in which we obtained demographic, clinical, laboratory data and characteristics of the GD, in addition to investigating cardiorespiratory function, focusing on the detection of pulmonary hypertension. Patients were separated into two groups: thyrotoxicosis and euthyroidism. Ninety patients with GD of both sexes, over 18 years of age, were included. The cardiorespiratory assessment included an echocardiographic evaluation, a questionnaire of specific symptoms, spirometry and a six-minute walk test.

RESULTS

The hyperthyroid group included 42 patients (47.73%) and the euthyroid group 46 patients (52.27%); 78 were women (86.67%). The prevalence of pulmonary hypertension between the hyperthyroidism (48.57%) and the euthyroidism (29.41%) groups was not different. Free thyroxine levels (FT4) (OR 1.266), higher left atrium volume (OR 1.113) and right ventricle diameter were associated with pulmonary hypertension. A direct correlation between FT4 with forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1), as also an inverse correlation between initial oxygen saturation (SpO2) with diagnostic time and drop SpO2 with the ratio between the diastolic velocity E of the mitral flow and the diastolic velocity of the mitral ring (E/e') were observed in the euthyroid group. An inverse correlation between FT4 levels with walked distance as % of predicted value, and a direct correlation between E/e' ratio and walked distance as % of predicted value were observed in the hyperthyroid group.

CONCLUSION

We emphasize the importance of a cardiorespiratory reassessment in GD, even after a long-term control of the thyrotoxic state, as we demonstrate that about 30% of these patients remain with PH and are subject to specific treatment.

Autoimmune Polyendocrine Syndrome Complicated by Pulmonary Hypertension

A 24-years old female was admitted for acute renal failure, melanoderma, hyponatremia, and hyperkalemia. The clinical suspicion of Addison's disease was confirmed by laboratory test and the appropriate replacement therapy with corticosteroids and fludrocortisone was started. In the meantime primary hypothyroidism and diabetes mellitus type 1 were disclosed and treated, thus fulfilling a diagnosis of autoimmune polyendocrine syndrome type 2. Eighteen months later she was admitted for right-sided heart failure. The work-up allowed to diagnose pulmonary arterial hypertension. Here, we report the clinical course and discuss the putative link between these two rare diseases.

Beyond the Lungs: Systemic Manifestations of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a disease characterized by progressive loss and remodeling of the pulmonary arteries, resulting in right heart failure and death. Until recently, PAH was seen as a disease restricted to the pulmonary circulation. However, there is growing evidence that patients with PAH also exhibit systemic vascular dysfunction, as evidenced by impaired brachial artery flow-mediated dilation, abnormal cerebral blood flow, skeletal myopathy, and intrinsic kidney disease. Although some of these anomalies are partially due to right ventricular insufficiency, recent data support a mechanistic link to the genetic and molecular events behind PAH pathogenesis. This review serves as an introduction to the major systemic findings in PAH and the evidence that supports a common mechanistic link with PAH pathophysiology. In addition, it discusses recent studies describing morphological changes in systemic vessels and the possible role of bronchopulmonary anastomoses in the development of plexogenic arteriopathy. On the basis of available evidence, we propose a paradigm in which metabolic abnormalities, genetic injury, and systemic vascular dysfunction contribute to systemic manifestations in PAH. This concept not only opens exciting research possibilities but also encourages clinicians to consider extrapulmonary manifestations in their management of patients with PAH.

The Association of Autoantibodies in Hyperthyroid Heart Disease Combined with Pulmonary Hypertension

Hyperthyroidism is a clinical state that results from increased thyroid hormone levels which has a significant impact on cardiac function and structure. Graves' disease is the most common cause of hyperthyroidism in iodine-replete areas. Hyperthyroid heart disease may be associated with pulmonary hypertension in patients who have overt hyperthyroidism. To investigate the association of pulmonary hypertension induced by hyperthyroid heart disease and autoantibody, one hundred and one cases with hyperthyroid heart disease who were consecutively admitted to the inpatient department of endocrinology and metabolism of the Shandong Provincial Hospital between November 2014 and April 2018 were collected and analyzed statistically. According to the Independent samples T-test, variance analysis, chi-square test, Pearson linear correlation analysis, and logistic regression, there was a good correlation between pulmonary artery systolic pressure and thyroid stimulating hormone (TSH) and receptor antibodies (TRAb) (r = 0.264, P=0.025) (OR = 1.037, P=0.029), but there was no significant correlation between the pulmonary artery systolic pressure and other thyroid-related parameters (FT3, FT4, TSH, anti-TPO, and anti-TG). Based on variance analysis, PASP rose as the level of TRAb gets higher. What is more, patients with HHD combined with PH showed a significantly higher serum level of TRAb; moreover, serum TRAb concentration was remarkably correlated with the PASP level. Therefore, TRAb participates in the process of pulmonary hypertension caused by hyperthyroid heart disease.

Effect of experimentally induced hypothyroidism during gestation period on activity dependent neurotrophic factor (ADNF) in newborn rat brain tissue

Purpose The aim of the study was to evaluate the effects of prenatal hypothyroidism on neonatal rats by the way of activity-dependent neuroprotective factor (ADNF) expression. Methods Twenty-one Wistar albino neonatal rats were divided into two subgroups; a control group and neonatal rats with experimental maternal hypothyroidism. Hypothyroidism was induced by using propylthiouracil (PTU). Neonatal rats obtained PTU from breast milk continuously for 1 week after birth. The rats from the control group were fed only normal feed and water. After birth, body weight and blood thyroid hormone levels were tested. Glial fibrillary acidic protein (GFAP), Slug, Numb, Notch-1 and ADNF antibodies were used for immunohistochemical analysis. Real-time polymerase chain reaction (RT-PCR) and Western blotting analyses were used to evaluate ADNF gene expression levels from 1-week-old rat's brain. Results There was no difference between the two groups for birth weights. The thyroxine (T4) level from the experimental group was <0.4 ng/mL, and it was 0.8 ng/mL for the control group. It was shown that, the results from the experimental group samples had significantly lower ADNF mRNA levels than control group (p < 0.05). The increase from GFAP and Numb expression and decrease from Slug expression were shown in the experimental group. Local differences were identified for ADNF and a decrease was shown in both sides of brain. There was no difference for Notch-1 expression for both groups. Conclusion In this study, decreasing ADNF expression might contribute to developing neurological problems in congenital hypothyroidism.

Prospective Echocardiographic Evaluation of the Right Ventricle and Pulmonary Arterial Pressure in Hyperthyroid Patients

BACKGROUND

Pulmonary arterial hypertension (PAH) occurs in 35% to 65% of hyperthyroid patients. Despite this high frequency, only a few authors have examined the effects of hyperthyroidism treatment on PAH and the right ventricle. We evaluated the effects of hyperthyroidism and its reversal on cardiovascular structure and function using Doppler echocardiography.

METHODS

We prospectively evaluated 32 patients (42.5±11.9years old) with thyrotoxicosis. Exclusion criteria included previous cardiovascular disease. An echocardiogram was performed at the time of hyperthyroidism diagnosis and after normalisation of free thyroxine (T4) levels. Patients were divided into two groups according to the presence or absence of PAH at the diagnosis, or at two moments, before and after T4 normalisation.

RESULTS

Graves' disease was the most frequent aetiology (75%) of hyperthyroidism. Pulmonary arterial hypertension was observed in 43.8% of patients. Free T4 concentration was higher in PAH than non-PAH patients. Free T4 normalised after 5 (2.0-10.5; median and percentiles) months of treatment. Cardiac chamber sizes and cardiac output were higher in PAH. Right ventricular (RV) systolic function was impaired in PAH. Cardiac output and free T4 (r=0.42; p<0.05) correlated with pulmonary artery systolic pressure (PASP). Cardiac chamber size, cardiac output, left ventricular ejection fraction, and PASP (34.0±8.6 to 21.7±4.5mmHg) reduced after treatment. Right ventricular myocardial performance index and fractional area change improved after T4 normalisation.

CONCLUSIONS

Pulmonary arterial hypertension is highly prevalent in hyperthyroid patients and is combined with increased cardiac chambers size and cardiac output, and impaired RV function. Cardiovascular changes are reversible after T4 normalisation in patients without cardiovascular disease.

Echocardiographic evolution of pulmonary hypertension in female patients with hyperthyroidism

Objective:

The objective of this study was to highlight the impact of increased cardiac output (CO) and/or pulmonary vascular resistance (PVR) on the occurrence and evolution of pulmonary hypertension (PH) in hyperthyroidism and to follow their evolution in patients under therapy.

Methods:

Our study group consisted of 142 women with hyperthyroidism of different severities and etiologies. We divided our patients into three groups: groups A (overt hyperthyroidism), B (recurrent disease), and C (subclinical forms). We performed echocardiography to determine echocardiographically estimated systolic pulmonary arterial pressure (eePAP), CO, and PVR before and at 3, 6, and 12 months after treatment with thyroid suppression therapy and beta-blockers.

Results:

In our study group we documented PH of various severities in 73 patients (51.4%). Increased CO, induced mostly by hyperthyroidism-specific tachycardia, was frequently detected in overt hyperthyroidism and also augmented PVR, as documented in 43.66% of patients with severe and recurrent forms. For all patients with PH, we emphasized a strong correlation between eePAP and PVR level (r=0.854, p<0.0001) and a moderate one with CO (r=0.437, p<0.0001) and with hyperthyroidism duration (r=0.545, p<0.0001). Under therapy, CO rapidly normalized and PVR significantly decreased in groups A and C. In group B, the reduction was modest and statistically significant.

Conclusion:

The pathophysiological mechanisms responsible for the occurrence of PH are elevated CO and PVR. While increased CO is rapidly alleviated under therapy, elevated eePAP and PVR persist in recurrent cases and are responsible for the perpetuation of PH.

Pulmonary hypertension associated with antiphospholipid antibody: Call for a screening tool?

Antiphospholipid (aPL) antibodies are antibodies specific for anionic phospholipids. They are immunoglobulins that attack phospholipids, phospholipid-binding proteins, or phospholipid-protein complexes and are detected in anticardiolipin and lupus anticoagulant assays. aPL antibodies are often associated with antiphospholipid syndrome (APS) which can be idiopathic or from secondary causes such as systemic lupus erythematosus (SLE), infection or drugs. They have also been shown to be associated with Pulmonary Hypertension. We conducted a review of the literature that included all articles on PubMed with keywords 'antiphospholipid antibody' and 'pulmonary hypertension' between January 1980 and July 2017 and identified 217 articles. A total of 47 articles were found to be relevant to the topic and included as references. We ascertained that aPL antibodies have been implicated in the development of both idiopathic pulmonary arterial hypertension (PAH) and PAH associated with connective tissue disease (CTD). aPL antibodies were also noted to be associated with left-sided valvular heart disease that can lead to pulmonary venous hypertension (PVH). Patients with anitiphospholipid antibody syndrome (Diagnostic criteria incudes +aPL antibodies) were noted to have a high risk of developing chronic thromboembolic pulmonary hypertension (CTEPH). A recent study also found a positive association of aPL antibodies with ILD and PH in patients with systemic sclerosis. While association between autoimmune thyroid disease and PH (Group V PH), and autoimmune thyroid disease and aPL antibodies is established, no studies linked these three phenomena together. Thus, aPL antibodies had an association with all WHO groups of Pulmonary hypertension (PH). In this review article, we study the association and discuss the need for screening for PH in patients with positive aPL antibodies.

Comparison of Linear and Non-linear Regression Analysis to Determine Pulmonary Pressure in Hyperthyroidism

Objectives:

This study aimed at assessing the incidence of pulmonary hypertension (PH) at newly diagnosed hyperthyroid patients and at finding a simple model showing the complex functional relation between pulmonary hypertension in hyperthyroidism and the factors causing it.

Methods:

The 53 hyperthyroid patients (H-group) were evaluated mainly by using an echocardiographical method and compared with 35 euthyroid (E-group) and 25 healthy people (C-group). In order to identify the factors causing pulmonary hypertension the statistical method of comparing the values of arithmetical means is used. The functional relation between the two random variables (PAPs and each of the factors determining it within our research study) can be expressed by linear or non-linear function. By applying the linear regression method described by a first-degree equation the line of regression (linear model) has been determined; by applying the non-linear regression method described by a second degree equation, a parabola-type curve of regression (non-linear or polynomial model) has been determined. We made the comparison and the validation of these two models by calculating the determination coefficient (criterion 1), the comparison of residuals (criterion 2), application of AIC criterion (criterion 3) and use of F-test (criterion 4).

Results:

From the H-group, 47% have pulmonary hypertension completely reversible when obtaining euthyroidism. The factors causing pulmonary hypertension were identified: previously known- level of free thyroxin, pulmonary vascular resistance, cardiac output; new factors identified in this study- pretreatment period, age, systolic blood pressure. According to the four criteria and to the clinical judgment, we consider that the polynomial model (graphically parabola- type) is better than the linear one.

Conclusions:

The better model showing the functional relation between the pulmonary hypertension in hyperthyroidism and the factors identified in this study is given by a polynomial equation of second degree where the parabola is its graphical representation.

Relationship Among Pulmonary Hypertension, Autoimmunity, Thyroid Hormones and Dyspnea in Patients With Hyperthyroidism

OBJECTIVE

Previous studies have reported conflicting results regarding the mechanisms underlying the pathophysiology of pulmonary hypertension (PHT) in patients with hyperthyroidism. Therefore, in this study, we investigated the association between PHT and thyroid-stimulating hormone (TSH) receptor antibody, thyroid peroxidase antibody, thyroglobulin antibody, TSH, fT3, fT4 and dyspnea during daily activities in a large population of patients with hyperthyroidism.

METHODS

A total of 129 consecutive patients with hyperthyroidism, 37 with hypothyroidism and 38 euthyroid controls were enrolled in this study. The modified medical research council scale was used for the assessment of dyspnea in daily activities. All the patients and euthyroid controls underwent transthoracic echocardiography for the assessment of PHT.

RESULTS

Mild PHT was present in 35%, 36%, 13.5% and 5% of the patients with Graves׳ disease, toxic multinodular goiter, hypothyroidism and euthyroid controls, respectively. Pulmonary vascular resistance (PVR) was higher in hyperthyroid patients with PHT than in those without PHT. Moreover, a significant positive correlation was found between modified medical research council scale and pulmonary artery systolic pressure as well as PVR in patients with hyperthyroidism. No association was found between PHT and serum TSH receptor antibody, thyroid peroxidase antibody, thyroglobulin antibody, TSH, fT3 and fT4 levels.

CONCLUSIONS

Mild PHT is present in a significant proportion of patients with hyperthyroidism, regardless of etiology. PVR appears to be the main cause of PHT in patients with hyperthyroidism, and neither autoimmunity nor thyroid hormones are associated with PHT in these patients. Mild dyspnea during daily activities in patients with hyperthyroidism may be related to PHT; however, severe dyspnea requires further evaluation.

Severe Hypothyroidism due to the Loss of Therapeutic Efficacy of l-Thyroxine in a Patient with Esophageal Complication Associated with Systemic Sclerosis

BACKGROUND

Thyroid function abnormalities and thyroid autoantibodies have been frequently described in patients with systemic autoimmune diseases as systemic sclerosis (SSc). Serum TSH levels are higher in SSc patients with more severe skin diseases and a worse modified Rodnan skin score. Asymptomatic esophageal involvement due to SSc has never been described as a cause of severe hypothyroidism due to l-thyroxine (l-T4) malabsorption in patients with Hashimoto's thyroiditis (HT) and SSc.

CASE REPORT

Here, we report a case of a 56-year-old female affected by both SSc and HT who developed severe hypothyroidism due to the loss of therapeutic efficacy of l-T4. Therapeutic failure resulted from the altered l-T4 absorption because of SSc esophageal complications. Clinical findings improved after the administration of oral liquid l-T4. Thyroid function completely normalized with a full clinical recovery, the disappearance of the pericardial effusion and the improvement of the pulmonary pressure.

CONCLUSION

A recognition of a poor absorption is crucial in patients with hypothyroidism and SSc to reduce the risk of the subsequent adverse events. This case suggests the importance of clinical and laboratory surveillance in patients with SSc and HT because the systemic complications of these dysfunctions may worsen the prognosis of hypothyroid SSc/HT patients.

Hematological disorders and pulmonary hypertension

Pulmonary hypertension (PH), a serious disorder with a high morbidity and mortality rate, is known to occur in a number of unrelated systemic diseases. Several hematological disorders such as sickle cell disease, thalassemia and myeloproliferative diseases develop PH which worsens the prognosis. Associated oxidant injury and vascular inflammation cause endothelial damage and dysfunction. Pulmonary vascular endothelial damage/dysfunction is an early event in PH resulting in the loss of vascular reactivity, activation of proliferative and antiapoptotic pathways leading to vascular remodeling, elevated pulmonary artery pressure, right ventricular hypertrophy and premature death. Hemolysis observed in hematological disorders leads to free hemoglobin which rapidly scavenges nitric oxide (NO), limiting its bioavailability, and leading to endothelial dysfunction. In addition, hemolysis releases arginase into the circulation which converts L-arginine to ornithine, thus bypassing NO production. Furthermore, treatments for hematological disorders such as immunosuppressive therapy, splenectomy, bone marrow transplantation, and radiation have been shown to contribute to the development of PH. Recent studies have shown deregulated iron homeostasis in patients with cardiopulmonary diseases including pulmonary arterial hypertension (PAH). Several studies have reported low iron levels in patients with idiopathic PAH, and iron deficiency is an important risk factor. This article reviews PH associated with hematological disorders and its mechanism; and iron homeostasis and its relevance to PH.