Evidence for Systemic Endothelial Dysfunction in Patients and First-Order Relatives With Pulmonary Arterial Hypertension

Endothelial Function Correlates With Pulmonary Pressures in Subjects With Clinically Suspected Pulmonary Hypertension

Impaired pulmonary circulation hemodynamics are characteristic of pulmonary hypertension (PH). We therefore sought to evaluate possible correlations between endothelial function noninvasively assessed by brachial artery flow-mediated dilation (FMD) and hemodynamic parameters at right-sided cardiac catheterization in patients with clinically suspected PH. Consecutive outpatients with suspected PH were enrolled in the study. In all patients, endothelial function was assessed by FMD and hemodynamic parameters (pulmonary artery pressure [PAP]); pulmonary vascular resistances [PVR]) were derived by right-sided cardiac catheterization. For this study, 95 consecutive patients with suspected PH were enrolled (mean age 63 ± 13 years, 58% male) and included in the analysis. FMD values were significantly correlated with systolic (s)PAP levels (r = -0.29, p = 0.016); correlation with PVR was of borderline significance (r = -0.21, p = 0.78). After multivariable regression analysis including age, gender, tricuspid annular plane systolic excursion and peak tricuspid regurgitation velocity (peak TRV), and FMD, the latter remained significantly correlated with systolic pulmonary artery pressure (sPAP) values (B = -47, p = 0.02). After classifying patients according to median levels of peak TRV and FMD into 3 groups (neither, either, or both impaired), progressively increased levels of sPAP, mean PAP, and PVR were found (p for trend <0.001 in all cases). FMD values were inversely related to sPAP levels in a small population of patients with clinically suspected PH. In combination with peak TRV levels, FMD values noninvasively assessed were predictive of increased sPAP, mean PAP, and PVR.

Association between preoperative albumin and length of hospital stay in non-cardiac surgery patients with pulmonary hypertension: A secondary retrospective analysis

To explore the risk factors affecting the length of hospital stay (LOS) as well as to examine the relationship between preoperative serum albumin levels and LOS following non-cardiac, non-obstetric surgery in patients with pulmonary hypertension (PHTN). This study represents a secondary retrospective analysis based on 287 non-cardiac, non-obstetric procedures performed on 195 PTHN patients at a single institution in the USA between 2007 and 2013. The primary outcome was the LOS. We conducted a multiple logistic regression analysis to compare the LOS between the 2 groups, divided at a serum albumin level of 3.5 g/dL. After adjusting for multiple covariates, the ORs for the long length of stay (LOS > 7 days) for the high group(albumin > 3.5 g/dL) compared with the low group (albumin ≤ 3.5 g/dL) were 0.35 (95%CI: 0.21~0.6), 0.41 (95%CI: 0.22 ~0.76), 0.41 (95%CI: 0.18~0.94) from model 2 to model 4. The stratified analysis results indicate that these findings are stable (p for trend > 0.05). In this study, it was observed that low levels of preoperative albumin were associated with an increased risk of prolonged hospital stay after non-cardiac, non-obstetric surgery in patients with PHTN. This implies that optimizing preoperative nutrition could potentially reduce the LOS for non-cardiac, non-obstetric surgery in patients with PHTN.

Identification of potential biomarkers for idiopathic pulmonary arterial hypertension using single-cell and bulk RNA sequencing analysis

Idiopathic pulmonary arterial hypertension (IPAH) is a rare and severe cardiopulmonary disease with a challenging prognosis, and its underlying pathogenesis remains elusive. A comprehensive understanding of IPAH is crucial to unveil potential diagnostic markers and therapeutic targets. In this study, we investigated cellular heterogeneity and molecular pathology in IPAH using single-cell RNA sequencing (scRNA-seq) analysis. Our scRNA-seq results revealed significant alterations in three crucial signaling pathways in IPAH: the hypoxia pathway, TGF β pathway, and ROS pathway, primarily attributed to changes in gene expression within arterial endothelial cells. Moreover, through bulk RNA sequencing analysis, we identified differentially expressed genes (DEGs) enriched in GO and KEGG pathways, implicated in regulating cell adhesion and oxidative phosphorylation in IPAH lungs. Similarly, DEGs-enriched pathways in IPAH arterial endothelial cells were also identified. By integrating DEGs from three IPAH datasets and applying protein-protein interaction (PPI) analysis, we identified 12 candidate biomarkers. Subsequent validation in two additional PAH datasets led us to highlight five potential biomarkers (CTNNB1, MAPK3, ITGB1, HSP90AA1, and DDX5) with promising diagnostic significance for IPAH. Furthermore, real-time quantitative polymerase chain reaction (RT-qPCR) confirmed significant differences in the expression of these five genes in pulmonary arterial endothelial cells from PAH mice. In conclusion, our findings shed light on the pivotal role of arterial endothelial cells in the development of IPAH. Furthermore, the integration of single-cell and bulk RNA sequencing datasets allowed us to pinpoint novel candidate biomarkers for the diagnosis of IPAH. This work opens up new avenues for research and potential therapeutic interventions in IPAH management.

Ventricular Function and Cardio-Ankle Vascular Index in Patients With Pulmonary Artery Hypertension

Aim

This study aims to evaluate the left ventricle (LV) systolic and diastolic function in patients with idiopathic pulmonary arterial hypertension (IPAH) and its correlation with systemic arterial stiffness assessed by cardio-ankle vascular index (CAVI).

Patient and methods

We included 37 patients with IPAH and 20 healthy people matched by age. All patients were assessed: vital signs, 6-minute walk test, NT-proBNP level, the CAVI, the right ventricular (RV) and LV function parameters, including ejection time (ET), tissue speckle-tracking values - global longitudinal strain (GLS) and strain rate (SR).

Results

The groups were matched by age, gender, BMI, office SBP and DBP. Patients with IPAH had higher heart rate, NT-proBNP level and lower ferritin level, GFR (CKD-EPI), SaO2 than healthy people. The mean CAVIleft was higher in IPAH patients than in the control group- 8.7±1.1 vs 7.5±0.9, P=0.007. Healthy people had significantly less E/e' and lower IVRT. LVET and RVET were shorter in IPAH patients. Patients with IPAH had mean LVGLS -(-17.6±4.8%) and 35.1% of them were with LVGLS ≤16% compared to healthy people -(-21.8±1.4%) and 0%, respectively. LVSR was significant less in IPAH patients, but in the normal range. We found significant correlations of CAVI with age, history of syncope, bilirubin, uric acid, total cholesterol, cardiac output, cardiac index, RVET, LVET and E/A. Multiple linear regression confirmed the independent significance for age (β=0.083±0.023, CI 0.033-0.133) and RVET (β=-0.018±0.005, CI -0.029 to -0.008) only. The risk to have CAVI ≥8 increased in 5.8 times in IPAH patients with RVET <248 ms (P=0.046). CAVI did not correlate with LVGLS and LVSR.

Conclusion

Significant worse systolic and diastolic LV functions were stated in pulmonary hypertensive patients compared to the control group. No LV GLS, no LV SR had significant associations with arterial stiffness evaluated by CAVI.

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.

Endothelial cells in the pathogenesis of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a devastating disease that involves pulmonary vasoconstriction, small vessel obliteration, large vessel thickening and obstruction, and development of plexiform lesions. PAH vasculopathy leads to progressive increases in pulmonary vascular resistance, right heart failure and, ultimately, premature death. Besides other cell types that are known to be involved in PAH pathogenesis (e.g. smooth muscle cells, fibroblasts and leukocytes), recent studies have demonstrated that endothelial cells (ECs) have a crucial role in the initiation and progression of PAH. The EC-specific role in PAH is multi-faceted and affects numerous pathophysiological processes, including vasoconstriction, inflammation, coagulation, metabolism and oxidative/nitrative stress, as well as cell viability, growth and differentiation. In this review, we describe how EC dysfunction and cell signalling regulate the pathogenesis of PAH. We also highlight areas of research that warrant attention in future studies, and discuss potential molecular signalling pathways in ECs that could be targeted therapeutically in the prevention and treatment of PAH.

Prognostic Significance of Systemic Arterial Stiffness Evaluated by Cardio-Ankle Vascular Index in Patients with Idiopathic Pulmonary Hypertension

BACKGROUND

In a previous study, the cardio-ankle vascular index (CAVI) was increased significantly in idiopathic pulmonary arterial hypertension (IPAH) patients compared to the healthy group and did not much differ from one in systemic hypertensives. In this study the relations between survival and CAVI was evaluated in patients with IPAH.

PATIENTS AND METHODS

We included 89 patients with new-diagnosed IPAH without concomitant diseases. Standard examinations, including right heart catheterization (RHC) and systemic arterial stiffness evaluation, were performed. All patients were divided according to CAVI value: the group with CAVI ≥ 8 (n = 18) and the group with CAVI < 8 (n = 71). The mean follow-up was 33.8 ± 23.7 months. Kaplan-Meier and Cox regression analysis were performed for the evaluation of our cohort survival and the predictors of death.

RESULTS

The group with CAVI≥8 was older and more severe compared to the group with CAVI< 8. Patients with CAVI≥8 had significantly reduced end-diastolic (73.79±18.94 vs 87.35±16.69 mL, P<0.009) and end-systolic (25.71±9.56 vs 33.55±10.33 mL, P<0.01) volumes of the left ventricle, the higher right ventricle thickness (0.77±0.12 vs 0.62±0.20 mm, P < 0.006), and the lower TAPSE (13.38±2.15 vs 15.98±4.4 mm, P<0.018). RHC data did not differ significantly between groups, except the higher level of the right atrial pressure in patients with CAVI≥ 8-11.38±7.1 vs 8.76±4.7 mmHg, P<0.08. The estimated overall survival rate was 61.2%. The CAVI≥8 increased the risk of mortality 2.34 times (CI 1.04-5.28, P = 0.041). The estimated Kaplan-Meier survival in the patients with CAVI ≥ 8 was only 46.7 ± 7.18% compared to patients with CAVI < 8 - 65.6 ± 4.2%, P = 0.035. At multifactorial regression analysis, the CAVI reduced but saved its relevance as death predictor - OR = 1.13, CI 1.001-1.871.

SUMMARY

We suggested the CAVI could be a new independent predictor of death in the IPAH population and could be used to better risk stratify this patient population if CAVI is validated as a marker in a larger multicenter trial.

Non-Invasive Assessment of Endothelial Dysfunction in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is characterised by an increased pressure in the pulmonary arterial circulation, resulting in the elevation of pulmonary vascular resistance. Pulmonary endothelial dysfunction and inflammation, triggered by shear stress and hypoxia, constitute the hallmarks of pulmonary vasculopathy by promoting endothelial and smooth muscle cells proliferation, vasoconstriction, and thrombosis. While research was predominantly focused on pulmonary vasculature, the investigation of peripheral endothelial damage in different vascular beds has attracted the interest over the last years. As a result, effective non-invasive methods that can assess the endothelial function and the architectural integrity have been utilized for the evaluation of pulmonary and peripheral vasculature. Non-invasive plethysmography, pulmonary flow reserve, nailfold videocapillaroscopy, near-infrared spectroscopy, and imaging techniques such as magnetic resonance angiography and perfusion imaging coupled by a number of biomarkers can be used for the assessment of peripheral vascular function in PAH individuals. In this review, we summarise and critically approach the current evidence of more systemic derangement of vascular function in PAH defined by novel, non-invasive methods employed for functional and morphological assessment of endothelium and microcirculation.

Pulmonary Vascular Disease as a Systemic and Multisystem Disease

Pulmonary arterial hypertension (PAH) is a disease of progressive pulmonary vascular remodeling due to abnormal proliferation of pulmonary vascular endothelial and smooth muscle cells and endothelial dysfunction. PAH is a multisystem disease with systemic manifestations and complications. This article covers the chronic heart failure syndrome, including the systemic consequences of right ventricle-pulmonary artery uncoupling and neurohormonal activation, skeletal and respiratory muscle effects, systemic endothelial dysfunction and coronary artery disease, systemic inflammation and infection, endocrine and metabolic changes, the liver and gut axis, sleep, neurologic complications, and skin and iron metabolic changes.

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.

Kidney dysfunction in patients with pulmonary arterial hypertension

Pulmonary arterial hypertension (PH) and chronic kidney disease (CKD) both profoundly impact patient outcomes, whether as primary disease states or as co-morbid conditions. PH is a common co-morbidity in CKD and vice versa. A growing body of literature describes the epidemiology of PH secondary to chronic kidney disease and end-stage renal disease (ESRD) (WHO group 5 PH). But, there are only limited data on the epidemiology of kidney disease in group 1 PH (pulmonary arterial hypertension [PAH]). The purpose of this review is to summarize the current data on epidemiology and discuss potential disease mechanisms and management implications of kidney dysfunction in PAH. Kidney dysfunction, determined by serum creatinine or estimated glomerular filtration rate, is a frequent co-morbidity in PAH and impaired kidney function is a strong and independent predictor of mortality. Potential mechanisms of PAH affecting the kidneys are increased venous congestion, decreased cardiac output, and neurohormonal activation. On a molecular level, increased TGF-β signaling and increased levels of circulating cytokines could have the potential to worsen kidney function. Nephrotoxicity does not seem to be a common side effect of PAH-targeted therapy. Treatment implications for kidney disease in PAH include glycemic control, lifestyle modification, and potentially Renin-Angiotensin-Aldosterone System (RAAS) blockade.

Sublingual microcirculation in pulmonary arterial hypertension

RATIONALE

Pulmonary arterial hypertension (PAH) is a pulmonary vasculopathy that leads to failure of the right ventricle and premature death.

OBJECTIVES

To determine whether the sublingual microcirculation is affected in patients with PAH compared with healthy age- and sex-matched control subjects.

METHODS

Using the CapiScope Handheld Video Capillaroscope we measured the sublingual microvasculature density, flow index, tortuosity, and curvature. Videos were acquired immediately after right heart catheterization, and determinations were made off-line by investigators blinded to the group assignment or hemodynamics.

MEASUREMENTS AND MAIN RESULTS

In this cross-sectional pilot study, we included 26 patients with PAH (age, mean ± SD, 56.7 ± 10 yr; 77% women) and 14 healthy control subjects (age, 53.1 ± 12 yr; 71% women). Sublingual microvasculature flow index was lower (2 ± 0.66 vs. 2.7 ± 0.37, P < 0.001) with higher heterogeneity index (0.63 ± 0.63 vs. 0.25 ± 0.25, P = 0.04) in patients with PAH than control subjects. Microvasculature density was similar between the groups, but tortuosity was more pronounced in patients than control subjects (tort 0: 45 ± 19 vs. 23.6 ± 12, P = 0.001 and tort 1: 0.2 ± 0.16 vs. 0.06 ± 0.04, P < 0.001).

CONCLUSIONS

Patients with PAH showed lower sublingual microvasculature flow index and higher tortuosity compared with healthy age- and sex-matched control subjects. Further investigations are needed to assess whether this methodology can provide information on disease prognosis and/or response to therapy in this condition.

Systemic arterial endothelial function in children and young adults with idiopathic pulmonary arterial hypertension: is there a relation to pulmonary endothelium-dependent relaxation?

Pulmonary arterial endothelial function is known to be affected in patients with idiopathic pulmonary arterial hypertension (IPAH). Current reports also detected peripheral systemic arterial dysfunction in IPAH patients. The purpose of this study was to assess whether there is a relation between pulmonary arterial and systemic arterial endothelial function. Pulmonary arterial endothelium-dependent relaxation was assessed by changes in pulmonary blood flow in response to acetylcholine which were determined using intravascular Doppler flow measurements. Pulmonary flow reserve (PFR) was calculated as the ratio of pulmonary blood flow velocity in response to acetylcholine relative to baseline values. Systemic arterial endothelial function was assessed by the vascular response to reactive hyperemia, and was recorded non-invasively by peripheral arterial finger tonometry under standardized conditions. Thirteen children and young adults [mean age 16.7 (±5.6) years] with IPAH and 13 age-/gender-matched controls were included in the study. Digital reactive hyperemic index (RHI) of the IPAH patients was 1.54 (±0.69), and of the controls was 1.67 (±0.66) [p = 0.64]. The mean baseline flow velocity in the segmental pulmonary artery of all patients was 18.5 (±5.5) cm/s, increasing to 27.4 (±12.3) cm/s (p = 0.003) during acetylcholine infusion. The calculated mean PFR was 1.48 (±0.4). There was no significant correlation between the PFR and RHI (r = 0.19; p = 0.54). According to our results, systemic arterial endothelial function assessed by peripheral arterial finger tonometry was not significantly impaired in children and young adults with IPAH compared with age-/gender-matched controls. There was no correlation between systemic arterial and pulmonary arterial endothelial function, suggesting that different mechanisms may contribute to their pathogenesis and progression.

Brachial artery diameter and the right ventricle: the Multi-Ethnic Study of Atherosclerosis-right ventricle study

BACKGROUND

Endothelial dysfunction is associated with left ventricular morphology and long-term cardiovascular outcomes. The purpose of this study was to assess the relationship between both baseline brachial artery diameter and peripheral endothelial function (assessed by brachial artery ultrasonography) and right ventricular (RV) mass, RV end-diastolic volume (RVEDV), and RV ejection fraction (RVEF).

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) performed cardiac MRI and brachial artery ultrasonography on participants without clinical cardiovascular disease. Baseline brachial artery diameter and flow-mediated dilation were assessed.

RESULTS

The mean age was 60.9 years, and 49.4% of subjects were men (n = 2,425). In adjusted models, larger brachial artery diameter was strongly associated with greater RV mass (β = 0.55 g, P &lt; .001), larger RVEDV (β = 3.99 mL, P &lt; .001), and decreased RVEF (β = -0.46%, P = .03). These relationships persisted after further adjustment for the respective left ventricular parameters. Flow-mediated dilation was not associated with RV mass or RVEF and was only weakly associated with RVEDV.

CONCLUSIONS

Brachial artery diameter is associated with greater RV mass and RVEDV, as well as lower RVEF. Changes in the systemic arterial circulation may have pathophysiologic links to pulmonary vascular dysfunction or abnormalities in RV perfusion.

Peripheral arterial stiffness and endothelial dysfunction in idiopathic and scleroderma associated pulmonary arterial hypertension

OBJECTIVE

Pulmonary endothelial dysfunction and increased reflection of pulmonary pressure waves have been reported in pulmonary arterial hypertension (PAH). However, the systemic vascular involvement is not fully understood. Our study focused on the systemic arterial stiffness and endothelial involvement in idiopathic and scleroderma associated PAH.

METHODS

Peripheral arterial stiffness and endothelial function were evaluated in 38 patients with idiopathic (n = 28) and scleroderma associated (n = 10) PAH, and 21 control subjects (13 healthy; 8 with scleroderma and normal pulmonary pressure). All participants underwent clinical and cardiopulmonary evaluation. Arterial stiffness was measured through the fingertip tonometry derived augmentation index (AI), which is the boost increase in the late systolic pressure wave after the initial systolic shoulder. Endothelial function was measured by forearm blood flow dilatation response to brachial artery occlusion by a noninvasive plethysmograph (EndoPAT 2000), which is associated with nitric oxide-dependent vasodilatation and yields a peripheral arterial tone (PAT) ratio.

RESULTS

Mean systolic pulmonary pressure was 70.5 +/- 21.6 mm Hg (idiopathic-PAH) and 69.3 +/- 20 mm Hg (scleroderma-PAH). AI was higher in scleroderma patients (10.5% +/- 19.6% in healthy controls, 9.0% +/- 21.5% in idiopathic-PAH, 20.1% +/- 19.1% in scleroderma-PAH, and 24.4% +/- 18.9% in scleroderma-controls; nonsignificant). PAT ratio was significantly lower (p < 0.05) than control values in idiopathic-PAH and scleroderma-PAH (PAT ratio: control 2.20 +/- 0.25; idiopathic 1.84 +/- 0.51; scleroderma 1.66 +/- 0.66). AI was not correlated to endothelial dysfunction. There were no differences between the 2 PAH patient groups in age, body mass index, New York Heart Association classification, or 6-min walk test.

CONCLUSION

Our study shows a trend towards increased arterial stiffness in scleroderma (nonsignificant), and also peripheral endothelial dysfunction in idiopathic-PAH and in scleroderma-PAH. These findings suggest involvement of different vessels in scleroderma-PAH compared to idiopathic-PAH.

Peripheral endothelial dysfunction in patients with pulmonary arterial hypertension

BACKGROUND

Pulmonary endothelium plays an important role in the mechanism of pulmonary arterial hypertension (PAH). However, there is only a few data regarding the systemic endothelium in this syndrome. This study focused on the systemic endothelial involvement in PAH.

METHODS

Endothelial function was evaluated in 54 patients with idiopathic (n=28), scleroderma-associated (n=10), chronic thromboembolic (n=7), or Eisenmenger (n=9) PAH and 21 controls (13 healthy; eight scleroderma and normal pulmonary pressure). All underwent clinical evaluation, pulmonary assessment, echocardiography, and pulmonary cardiac stress test. Endothelial function was evaluated by measuring the forearm blood flow dilatation response to brachial arterial occlusion by a non-invasive plethysmograph, yielding a peripheral arterial tone (PAT) ratio.

RESULTS

The PAT ratio was significantly lower (p<0.05) than healthy controls in all patients except the Eisenmenger group (control: 2.20+/-0.25; idiopathic 1.84+/-0.51; scleroderma 1.66+/-0.66; thromboembolic 1.89+/-0.32; Eisenmenger 2.17+/-0.62). The impaired hyperemic response significantly correlated with disease severity, as measured by NYHA classification (r=-0.210, p=0.035), pulmonary pressure (r=-0.228, p=0.035), 6 min walking distance (r=0.215, p=0.047), and oxygen desaturation on effort (r=0.207, p=0.038). Mean systolic pulmonary pressure among patients was 54-99 mmHg.

CONCLUSION

A systemic component of endothelial dysfunction might be involved in idiopathic, scleroderma-associated and chronic thromboembolic PAH that is correlated with disease severity.

Circulating endothelial progenitor cells in patients with Eisenmenger syndrome and idiopathic pulmonary arterial hypertension

BACKGROUND

Impaired endothelial homeostasis underlies the pathophysiology of pulmonary arterial hypertension (PAH). We speculated that PAH patients are deficient in circulating endothelial progenitor cells (EPCs), potentially contributing to endothelial dysfunction and disease progression.

METHODS AND RESULTS

We recruited 41 patients with Eisenmenger syndrome (13 with Down syndrome), 55 with idiopathic PAH, and 47 healthy control subjects. Flow cytometry and in vitro assays were used to quantify EPCs and to assess cell function. The number of circulating CD34+, CD34+/AC133+, CD34+/KDR+, and CD34+/AC133+/KDR+ progenitor cells was low in Eisenmenger patients compared with healthy control subjects, and those with Down syndrome displayed even fewer EPCs. Reductions in EPC numbers correlated with New York Heart Association functional class, 6-minute walk distance, and plasma brain-type natriuretic peptide levels. The capacity of cultured peripheral blood mononuclear cells to form colonies and incorporate into tube-like structures was impaired in Eisenmenger patients. Idiopathic PAH patients had reduced numbers of EPCs, and the number of circulating EPCs correlated with invasive hemodynamic parameters in this cohort. Levels of immune inflammatory markers, cGMP, stable nitric oxide oxidation products, and asymmetric dimethylarginine were abnormal in patients with PAH and related to numbers of EPCs. Within the idiopathic PAH population, treatment with the phosphodiesterase inhibitor sildenafil was associated with a dose-dependent rise in EPC numbers, resulting in levels consistently above those found with other therapies.

CONCLUSIONS

Circulating EPC numbers are reduced in 2 well-characterized forms of PAH, which also exhibit raised levels of inflammatory mediators. Sildenafil treatment may represent a pharmacological means of increasing circulating EPC numbers long-term.

Non-thromboembolic pulmonary hypertension in multiple myeloma, after thalidomide treatment: a pilot study

BACKGROUND

Multiple myeloma (MM) is thrombogenic as a consequence of multiple hemostatic effects and endothelial damage. Thalidomide has been associated with an increased risk of thromboembolic pulmonary hypertension (PH). PH in the absence of venous thromboembolism has also been described in MM patients during thalidomide treatment.

AIM

Detection of clinical and subclinical nonthromboembolic PH in MM patients after thalidomide treatment.

PATIENTS AND METHODS

Eighty-two patients, 46-82 years (median age 61 years), 42 males, were studied. They underwent echocardiographic study at baseline, 1 month thereafter, 6 months later and whenever symptoms indicating deterioration of cardiac function appeared. Echocardiographic signs of PH were especially identified.

RESULTS

Clinical and echocardiographic evaluation revealed four patients (out of 82 patients, 4.87%) with PH. Nonimaging and imaging diagnostic methods excluded thromboembolic PH. Statistical analysis demonstrated significant correlation between structural heart disease and PH (r = 14.078; P = 0.008). No significant correlation between age (r = 0.770; P = 0.724), gender (r = 1.157; P = 0.285), International Staging System (ISS) (r = 0.316; P = 0.716) and PH was found.

CONCLUSIONS

Preexisted endothelial dysfunction due to structural cardiac disease enhances the vasoactive substances release causing increased pulmonary vascular resistance. Thalidomide possibly causes a vasodilator and vasoconstriction imbalance, which may cause abnormal pulmonary vascular response interfering to a vicious circle perpetuating PH.