Low-density lipoprotein cholesterol and survival in pulmonary arterial hypertension

Kidney Dysfunction, Hepatic Impairment, and Lipid Metabolism Abnormalities in Patients with Precapillary Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) is a global health issue that has profound medical and research implications.

METHODS

This retrospective study examined changes in renal and liver function, as well as lipid metabolism, over a 12-month period in 49 adult patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). All cases were admitted, managed, and followed up with in the PH Center, County Emergency Clinical Hospital of Targu Mures, Romania.

RESULTS

Kidney dysfunction was observed in 12.24% of cases at baseline, decreasing to 8.16% at 12 months, and CTEPH patients were more affected. In particular, CTEPH patients exhibited an improvement in renal function, confirmed by an increase in their glomerular filtration rates. Hepatic impairment was present in 57.14% of subjects at baseline, declining to 42.86% at 12 months, with significant improvements noted in the PAH group. Lipid metabolic dysregulations were experienced by 22.45% of all patients at baseline, decreasing to 16.33% at 6 months, with a slow elevation to 24.49% at 12 months, but with no statistically significant differences. Pharmacological regimens were adjusted in accordance with the PH groups, a patient's functional and clinical response, and laboratory tests.

CONCLUSIONS

Our results demonstrate the multi-organ damage in PH and the importance of individualized treatment approaches.

Markuszewski M, Da̧browska-Kugacka A. Metabolomics Meets Clinics: A Multivariate Analysis of Plasma and Urine Metabolic Signatures in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a severe, multifactorial, and frequently misdiagnosed disorder. The aim of this observational study was to compare the plasma and urine metabolomic profiles of PAH patients and healthy control subjects. Plasma and urine metabolomic profiles were analyzed using the GC-MS technique. Correlations between metabolite levels and clinical parameters among PAH patients, as well as the between-group differences, were evaluated. The linear discriminant analysis model, which allows for subject classification in terms of PAH with the highest possible precision, was developed and proposed. Plasma pyruvic acid, cholesterol, threonine, urine 3-(3-hydroxyphenyl)-3-hydroxypropanoic acid, butyric acid, 1,2-benzenediol, glucoheptonic acid, and 2-oxo-glutaric acid were found to build a relatively accurate classification model for PAH patients. The model reached an accuracy of 91% and significantly improved subject classification (OR = 119 [95% CI: 20.3-698.3], p < 0.0001). Five metabolites were detected in urine that provide easily available and noninvasive tests as compared to right heart catheterization. The selected panel of metabolites has potential for early recognition of patients with dyspnea and faster referral to a reference center.

Association of non-insulin-based insulin resistance indices with disease severity and adverse outcome in idiopathic pulmonary arterial hypertension: a multi-center cohort study

BACKGROUND

Insulin resistance (IR) plays an important role in the pathophysiology of cardiovascular disease. Recent studies have shown that diabetes mellitus and impaired lipid metabolism are associated with the severity and prognosis of idiopathic pulmonary arterial hypertension (IPAH). However, the relationship between IR and pulmonary hypertension is poorly understood. This study explored the association between four IR indices and IPAH using data from a multicenter cohort.

METHODS

A total of 602 consecutive participants with IPAH were included in this study between January 2015 and December 2022. The metabolic score for IR (METS-IR), triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio, triglyceride and glucose (TyG) index, and triglyceride-glucose-body mass index (TyG-BMI) were used to quantify IR levels in patients with IPAH. The correlation between non-insulin-based IR indices and long-term adverse outcomes was determined using multivariate Cox regression models and restricted cubic splines.

RESULTS

During a mean of 3.6 years' follow-up, 214 participants experienced all-cause death or worsening condition. Compared with in low to intermediate-low risk patients, the TG/HDL-C ratio (2.9 ± 1.7 vs. 3.3 ± 2.1, P = 0.003) and METS-IR (34.5 ± 6.7 vs. 36.4 ± 7.5, P < 0.001) were significantly increased in high to intermediate-high risk patients. IR indices correlated with well-validated variables that reflected the severity of IPAH, such as the cardiac index and stroke volume index. Multivariate Cox regression analyses indicated that the TyG-BMI index (hazard ratio [HR] 1.179, 95% confidence interval [CI] 1.020, 1.363 per 1.0-standard deviation [SD] increment, P = 0.026) and METS-IR (HR 1.169, 95% CI 1.016, 1.345 per 1.0-SD increment, P = 0.030) independently predicted adverse outcomes. Addition of the TG/HDL-C ratio and METS-IR significantly improved the reclassification and discrimination ability beyond the European Society of Cardiology (ESC) risk score.

CONCLUSIONS

IR is associated with the severity and long-term prognosis of IPAH. TyG-BMI and METS-IR can independently predict clinical worsening events, while METS-IR also provide incremental predictive performance beyond the ESC risk stratification.

Blood Cholesterol and Triglycerides Associate with Right Ventricular Function in Pulmonary Hypertension

Background

Blood lipids are dysregulated in pulmonary hypertension (PH). Lower high-density lipoproteins cholesterol (HDL-C) and low-density lipoproteins cholesterol (LDL-C) are associated with disease severity and death in PH. Right ventricle (RV) dysfunction and failure are the major determinants of morbidity and mortality in PH. This study aims to test the hypothesis that dyslipidemia is associated with RV dysfunction in PH.

Methods

We enrolled healthy control subjects (n=12) and individuals with PH (n=30) (age: 18-65 years old). Clinical characteristics, echocardiogram, 2-[18F] fluoro-2-deoxy-D-glucose positron emission tomography (PET) scan, blood lipids, including total cholesterol (TC), triglycerides (TG), lipoproteins (LDL-C and HDL-C), and N-terminal pro-B type Natriuretic Peptide (NT-proBNP) were determined.

Results

Individuals with PH had lower HDL-C [PH, 41±12; control, 56±16 mg/dL, p<0.01] and higher TG to HDL-C ratio [PH, 3.6±3.1; control, 2.2±2.2, p<0.01] as compared to controls. TC, TG, and LDL-C were similar between PH and controls. Lower TC and TG were associated with worse RV function measured by RV strain (R=-0.43, p=0.02 and R=-0.37, p=0.05 respectively), RV fractional area change (R=0.51, p<0.01 and R=0.48, p<0.01 respectively), RV end-systolic area (R=-0.63, p<0.001 and R=-0.48, p<0.01 respectively), RV end-diastolic area: R=-0.58, p<0.001 and R=-0.41, p=0.03 respectively), and RV glucose uptake by PET (R=-0.46, p=0.01 and R=-0.30, p=0.10 respectively). NT-proBNP was negatively correlated with TC (R=-0.61, p=0.01) and TG (R=-0.62, p<0.02) in PH.

Conclusion

These findings confirm dyslipidemia is associated with worse right ventricular function in PH.

Metabolic Syndrome: A Narrative Review from the Oxidative Stress to the Management of Related Diseases

Metabolic syndrome (MS) is a growing disorder affecting thousands of people worldwide, especially in industrialised countries, increasing mortality. Oxidative stress, hyperglycaemia, insulin resistance, inflammation, dysbiosis, abdominal obesity, atherogenic dyslipidaemia and hypertension are important factors linked to MS clusters of different pathologies, such as diabesity, cardiovascular diseases and neurological disorders. All biochemical changes observed in MS, such as dysregulation in the glucose and lipid metabolism, immune response, endothelial cell function and intestinal microbiota, promote pathological bridges between metabolic syndrome, diabesity and cardiovascular and neurodegenerative disorders. This review aims to summarise metabolic syndrome's involvement in diabesity and highlight the link between MS and cardiovascular and neurological diseases. A better understanding of MS could promote a novel strategic approach to reduce MS comorbidities.

Case Report: Two Case Reports of Pulmonary Hypertension after mRNA COVID-19 Vaccination

BACKGROUND

We herein report two cases of sudden onset symptomatic pulmonary hypertension after coronavirus disease 2019 (COVID-19) vaccination.

CASE SUMMARY

Pulmonary hypertension in previously healthy adult males occurred within three weeks of receiving the second dose of the Pfizer (BNT162b2) mRNA COVID-19 vaccine from different lots. Both patients experienced a sudden onset of severe fatigue and dyspnea on exertion with negative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) testing. The diagnosis was made by serial transthoracic echocardiography in the first case and by both transthoracic echocardiography and right heart catheterization in the second. Both cases resulted in functional limitations and likely permanent organ damage. No evidence of pulmonary emboli was detected in either case.

DISCUSSION

Pulmonary hypertension is a serious disease characterized by damage to lung vasculature and restricted blood flow through narrowed arteries from the right to left heart. The onset of symptoms is typically insidious, progressive and incurable, leading to right heart failure and premature death. The World Health Organization (WHO) classifies pulmonary hypertension into five categories and recently re-defined it as a resting mean pulmonary artery pressure greater than 20 mmHg. Sudden onset pulmonary hypertension would only be expected in the settings of surgical pneumonectomy or massive pulmonary emboli with compromise of at least 50% of the lung vasculature. We present here two novel cases of sudden onset pulmonary hypertension without evidence of pulmonary emboli, both of which occurred after receiving a COVID-19 mRNA vaccine.

Impact of diabetes mellitus on disease severity and patient survival in idiopathic pulmonary arterial hypertension: data from the Polish multicentre registry (BNP-PL)

BACKGROUND

Recent studies revealed that alterations in glucose and lipid metabolism in idiopathic pulmonary arterial hypertension (IPAH) are associated with disease severity and poor survival. However, data regarding the impact of diabetes mellitus (DM) on the prognosis of patients with IPAH remain scarce. The aim of our study was to determine that impact using data from a national multicentre prospective pulmonary hypertension registry.

METHODS

We analysed data of adult patients with IPAH from the Database of Pulmonary Hypertension in the Polish population (BNP‑PL) between March 1, 2018 and August 31, 2020. Upon admission, clinical, echocardiographic, and haemodynamic data were collected at 21 Polish IPAH reference centres. The all-cause mortality was assessed during a 30-month follow-up period. To adjust for differences in age, body mass index (BMI), and comorbidities between patients with and without DM, a 2-group propensity score matching was performed using a 1:1 pairing algorithm.

RESULTS

A total of 532 patients with IPAH were included in the study and 25.6% were diagnosed with DM. Further matched analysis was performed in 136 patients with DM and 136 without DM. DM was associated with older age, higher BMI, more advanced exertional dyspnea, increased levels of N-terminal pro-brain natriuretic peptide, larger right atrial area, increased mean right atrial pressure, mean pulmonary artery pressure, pulmonary vascular resistance, and all-cause mortality compared with no DM.

CONCLUSIONS

Patients with IPAH and DM present with more advanced pulmonary vascular disease and worse survival than counterparts without DM independently of age, BMI, and cardiovascular comorbidities.

Simvastatin and dehydroepiandrosterone sulfate effects against hypoxic pulmonary hypertension are not additive

Pulmonary hypertension is a group of disorders characterized by elevated mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance. To test our hypothesis that combining two drugs useful in experimental pulmonary hypertension, statins and dehydroepiandrosterone sulfate (DHEA S), is more effective than either agent alone, we induced pulmonary hypertension in adult male rats by exposing them to hypoxia (10%O2) for 3 weeks. We treated them with simvastatin (60 mg/l) and DHEA S (100 mg/l) in drinking water, either alone or in combination. Both simvastatin and DHEA S reduced mPAP (froma mean±s.d. of 34.4±4.4 to 27.6±5.9 and 26.7±4.8 mmHg, respectively), yet their combination was not more effective (26.7±7.9 mmHg). Differences in the degree of oxidative stress (indicated by malondialdehydeplasma concentration),the rate of superoxide production (electron paramagnetic resonance), or blood nitric oxide levels (chemiluminescence) did not explain the lack of additivity of the effect of DHEA S and simvastatin on pulmonary hypertension. We propose that the main mechanism of both drugs on pulmonary hypertension could be their inhibitory effect on 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, which could explain their lack of additivity.

Biomarkers in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a severe medical condition characterized by elevated pulmonary vascular resistance (PVR), right ventricular (RV) failure, and death in the absence of appropriate treatment. The progression and prognosis are strictly related to the etiology, biochemical parameters, and treatment response. The gold-standard test remains right-sided heart catheterization, but dynamic monitoring of systolic pressure in the pulmonary artery is performed using echocardiography. However, simple and easily accessible non-invasive assays are also required in order to monitor this pathology. In addition, research in this area is in continuous development. In recent years, more and more biomarkers have been studied and included in clinical guidelines. These biomarkers can be categorized based on their associations with inflammation, endothelial cell dysfunction, cardiac fibrosis, oxidative stress, and metabolic disorders. Moreover, biomarkers can be easily detected in blood and urine and correlated with disease severity, playing an important role in diagnosis, prognosis, and disease progression.

Simvastatin and dehydroepiandrosterone sulfate effects against hypoxic pulmonary hypertension are not additive

Pulmonary hypertension is a group of disorders characterized by elevated mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance. To test our hypothesis that combining two drugs useful in experimental pulmonary hypertension, statins and dehydroepiandrosterone sulfate (DHEA S), is more effective than either agent alone, we induced pulmonary hypertension in adult male rats by exposing them to hypoxia (10%O2) for 3 weeks. We treated them with simvastatin (60 mg/l) and DHEA S (100 mg/l) in drinking water, either alone or in combination. Both simvastatin and DHEA S reduced mPAP (froma mean±s.d. of 34.4±4.4 to 27.6±5.9 and 26.7±4.8 mmHg, respectively), yet their combination was not more effective (26.7±7.9 mmHg). Differences in the degree of oxidative stress (indicated by malondialdehydeplasma concentration),the rate of superoxide production (electron paramagnetic resonance), or blood nitric oxide levels (chemiluminescence) did not explain the lack of additivity of the effect of DHEA S and simvastatin on pulmonary hypertension. We propose that the main mechanism of both drugs on pulmonary hypertension could be their inhibitory effect on 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, which could explain their lack of additivity.

Prognostic effect of pulmonary hypertension in patients with chronic kidney disease: Univariate and multivariate analyses of factors associated with survival

Background

Prognostic effect of pulmonary hypertension (PH) in patients with chronic kidney disease (CKD) is not fully clear yet, this study was designed to elucidate baseline characteristics of CKD patients with different severities of PH, the association between kidney indicators and PH severity, and survival factors in CKD patients with PH.

Methods

We extracted clinical data from electronic medical records of all patients diagnosed with PH in CKD from Jan 2016 to Dec 2020, and those with comorbid conditions causing PH were excluded. CKD stages were defined by estimated glomerular filtration rate thresholds. PH was defined as a systolic pulmonary artery pressure (sPAP) >35 mmHg estimated using echocardiograms. Demographics, clinical data, and test results were analyzed, and all-cause mortality data were obtained.

Results

A total of 137 patients were included in the study. The mean age of the participants was 60 (42.5, 67) years, the mean sPAP was 58 (51, 69.5) mmHg, and 40.9% of the patients were women. Moderate PH group had more patients undergoing dialysis and higher frequency of coronary heart disease. Moderate-severe PH group had higher parathyroid hormone levels and lower low-density lipoprotein levels. Severe PH group had better kidney function parameters and lower serum phosphorus levels. PH severity had no direct relationship with CKD stages. In the univariate analysis, age and PH severity influenced survival. Multivariate analysis also showed independent prognostic effects for age and sPAP. Kaplan-Meyer curve intuitively displayed the survival differences among CKD patients with different PH severity. Predictor values of nomogram identified from survival analyses enabled calculation of death probabilities for CKD with PH patients. Nomogram was validated by ROC analysis.

Conclusions

PH begins with early-stage CKD, and PH severity is not related to CKD progression. A higher pulmonary artery pressure and an older age are associated with an increased risk of death.

Decreased low‑density lipoprotein and the presence of pulmonary arterial hypertension among newly diagnosed drug‑naïve patients with systemic lupus erythematosus: D‑dimer as a mediator

Pulmonary arterial hypertension (PAH) is commonly associated with systemic lupus erythematosus (SLE). The present study investigated the relationship between coagulation and changes in lipid parameters in newly-diagnosed patients with SLE in the presence of PAH and whether the coagulation parameters were mediators between lipids and PAH presence. A total of 301 subjects scheduled for new-onset drug-naïve SLE were consecutively enrolled. Baseline data for patients without PAH and with PAH were gathered and compared. Coagulation and lipid parameters were compared across patients without lipid regulating and anticoagulation medications. Multivariable logistic regression model was applied to examine potential predictors of PAH in SLE. The relationships between them were examined using Spearman's correlation analysis. The relationship between coagulation index and lipids with SLE-PAH was evaluated using mediation analysis. Female patients accounted for 88.0% of the 301 subjects, and the average age was 32 years (range, 25-45 years). A total of 40 patients (13.3%) had PAH, and the average pulmonary artery systolic pressure (sPAP) was 55.825±26.67 mmHg. Patients with PAH were older and had higher levels of fibrin/fibrinogen degradation products (FDP), D-dimer, C-reactive protein, lower levels of complement 3, complement 4 and 25-hydroxy vitamin D3 compared with the non-PAH group. Multivariable logistic regression analysis showed that age and D-dimer were independent predictor factors for PAH. Among patients without lipid regulating and anticoagulation medications, patients in the PAH group had higher levels of D-dimer and FDP, and lower low-density lipoprotein (LDL) levels compared with patients without PAH. There was also a positive relationship between sPAP and D-dimer and FDP, and a negative relationship between sPAP and total cholesterol and LDL. Mediation analysis indicated that 25.61% of the effect of low LDL on PAH presence in systemic lupus erythematosus was mediated by D-dimer. Overall, the effect of low LDL on SLE-PAH appeared to be mediated by D-dimer, which mediated 25.61% of this effect.

A Systematic Review with Meta-analysis of Biomarkers for detection of Pulmonary Arterial Hypertension

Rationale

The blood is a rich source of potential biomarkers for the diagnosis of idiopathic and hereditary pulmonary arterial hypertension (iPAH and hPAH, referred to as “PAH”). While a lot of biomarkers have been identified for PAH, the clinical utility of these biomarkers often remains unclear. Here, we performed an unbiased meta-analysis of published biomarkers to identify biomarkers with the highest performance for detection of PAH.

Methods

A literature search (in PubMed, Embase.com, Clarivate Analytics/Web of Science Core Collection and Wiley/Cochrane Library) was performed up to 28 January 2021. Primary end points were blood biomarker levels in PAH versus asymptomatic controls or patients suspected of pulmonary hypertension (PH) with proven normal haemodynamic profiles.

Results

149 articles were identified by the literature search. Meta-analysis of 26 biomarkers yielded 17 biomarkers that were differentially expressed in PAH and non-PH control subjects. Red cell distribution width, low density lipid-cholesterol, d-dimer, N-terminal prohormone of brain natriuretic protein (NT-proBNP), interleukin-6 (IL-6) and uric acid were biomarkers with the largest observed differences, largest sample sizes and a low risk of publication bias. Receiver operating characteristic curves and sensitivity/specificity analyses demonstrated that NT-proBNP had a high sensitivity, but low specificity for PAH. For the other biomarkers, insufficient data on diagnostic accuracy with receiver operating characteristic curves were available for meta-analysis.

Conclusion

This meta-analysis validates NT-proBNP as a biomarker with high sensitivity for PAH, albeit with low specificity. The majority of biomarkers evaluated in this meta-analysis lacked either external validation or data on diagnostic accuracy. Further validation studies are required as well as studies that test combinations of biomarkers to improve specificity.

Meta-analysis of 26 biomarkers yielded 17 differentially expressed biomarkers in PAH. NT-proBNP had the highest diagnostic accuracy but had a low specificity for PAH. Other markers, including IL-6, RDW, LDL-c, D-dimer and UA, lacked clinical validation.https://bit.ly/3J4YAyC

Differential serum lipid distribution in IPAH and CHD-PAH patients

Lipid homeostasis is dysregulated in pulmonary arterial hypertension (PAH). A decrease in serum high- and low-density lipoprotein cholesterol (HDL-C and LDL-C) is significantly associated with the worse prognosis of PAH. However, no study has investigated the differential distribution of lipids in various PAH subtypes. We enrolled 190 patients in this retrospective study, which includes 20 patients with congenital heart disease without PAH (CHD-nonPAH), 101 patients with PAH associated with congenital heart disease (CHD-PAH), 69 patients with idiopathic PAH (IPAH) and 81 healthy controls. Laboratory parameters such as liver and renal function, serum lipids, C-reactive protein, N-terminal pro-brain natriuretic peptide (NT-proBNP), echocardiography, right heart catheterization and 6-min walk distance (6MWD) were performed. All types of cholesterol including HDL-C, LDL-C and total cholesterol (CHOL) were significantly lower in IPAH patients in association with right heart function. Although LDL-C and CHOL were lower in CHD-PAH, they were not associated with disease severity or heart failure. Thus, we conclude that IPAH and CHD-PAH patients exhibited a differential distribution pattern of serum lipids.

Increased serum PCSK9 in patients with idiopathic pulmonary arterial hypertension: insights from inflammatory cytokines

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is an important and major player in the pathophysiology of hypercholesterolemia and atherosclerosis. Recently, PCSK9 has been implicated in the pathogenesis of inflammatory diseases. Whether PCSK9 is involved in idiopathic pulmonary arterial hypertension (IPAH) remains unclear. This study aimed to investigate the relationship between PCSK9 and IPAH. Serum PCSK9, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1 β (IL-1β), and monocyte chemotactic protein-1 (MCP-1) were measured by enzyme linked immunosorbent assay. Transthoracic echocardiography was performed among 40 IPAH patients and 20 control subjects. Hemodynamic data were collected via right heart catheterization in patients with IPAH. Serum PCSK9, TNF-α, IL-6, IL-1β, and MCP-1 levels were significantly higher in IPAH patients than in control subjects (p < 0.001). Among enrolled IPAH patients, PCSK9 levels were higher in WHO-FC III/IV patients compared with those in WHO-FC I/II (p < 0.05), and were positively correlated with TNF-α, IL-6, MCP-1, N-Terminal pro-brain natriuretic peptide, pulmonary arterial systolic pressure (r = 0.653, p < 0.001), pulmonary arterial diastolic pressure (r = 0.466, p = 0.002), mean pulmonary arterial pressure (mPAP, r = 0.730, <0.001), pulmonary vascular resistance (r = 0.488, p = 0.001), and right ventricle diameter (r = 0.563, p < 0.001). In multiple regression analysis, mPAP was strongly associated with serum PCSK9 (β = 0.694, p < 0.001), independent of other variables. Receiver operating characteristic curve analysis showed the optimal cutoff value of serum PCSK9 concentration for predicting IPAH was 90.67 ng/ml, with a sensitivity of 90.0% and a specificity of 85.0%. In conclusion, IPAH patients had elevated serum PCSK9 levels which correlated the presence and severity of pulmonary hypertension. PCSK9 may be a novel potential therapeutic target.

Liver abnormalities in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a cardiopulmonary disease with high mortality. In recent years, it has been recognized that PAH is a multi-organ system disease, involving the systemic circulation, kidneys, skeletal muscles, and the central nervous system, among others. Right heart failure produces congestive hepatopathy, a disease state that has direct consequences on liver biochemistry, histology, and systemic glucose and lipid metabolism. This article aims to summarize the consequences of congestive hepatopathy with an emphasis on liver biochemistry, histology, and PAH-targeted therapy. Furthermore, PAH-specific changes in glucose and lipid metabolism will be discussed.

Plasma irisin levels are associated with hemodynamic and clinical outcome in idiopathic pulmonary arterial hypertension patients

Irisin has been considered to reflect oxidative stress. This study aimed to show whether plasma irisin levels are correlated with hemodynamic dysfunction and predict the clinical outcome of patients with idiopathic pulmonary arterial hypertension (IPAH). A total of 68 adult IPAH patients were prospectively recruited in the present study. Plasma irisin levels were measured by the ELISA method in enrolled IPAH patients. Baseline clinical characteristics, and hemodynamic and clinical outcome were compared according to different plasma irisin levels. IPAH patients were divided into high irisin group (irisin ≥ 7.3 μg/ml) and low irisin group (irisin < 7.3 μg/ml) according to median values of irisin levels. Total plasma cholesterol levels (P = 0.027) and low-density lipoprotein cholesterol (LDL-C) levels (P = 0.042) were higher in high irisin group and were positively correlated with plasma irisin levels. IPAH patients in low irisin group had a significantly higher mean pulmonary artery pressure (mPAP, P = 0.047), systolic pulmonary artery pressure (sPAP, P = 0.022), systolic right-ventricular pressure (sRVP, P = 0.007), mean right atrial pressure (mRAP, P = 0.043), and systolic right atrial pressure (sRAP, P = 0.020). mRAP, sRAP, and diastolic right atrial pressure (dRAP) were negatively correlated with plasma irisin levels. Low irisin group predicts adverse hemodynamic status and poor free of event survival rate (P = 0.030, log-rank test). Multivariate analysis indicates plasma irisin levels to be an independent predictor of prognosis in IPAH patients after adjusting for related covariates (HR 0.786; 95% CI 0.584, 0.957; P = 0.038). Plasma irisin levels may serve as a novel biomarker in IPAH patients for hemodynamic severity assessment and clinical outcome evaluation.

Involvement of Low-Density Lipoprotein Receptor in the Pathogenesis of Pulmonary Hypertension

Background

Recently, we and others have reported a causal role for oxidized lipids in the pathogenesis of pulmonary hypertension (PH). However, the role of low‐density lipoprotein receptor (LDL‐R) in PH is not known.

Methods and Results

We examined the role of LDL‐R in the development of PH and determined the efficacy of high‐density lipoprotein mimetic peptide 4F in mitigating PH. Explanted human lungs and plasma from patients with PH and control subjects were analyzed for gene expression, histological characteristics, and lipoprotein oxidation. Male LDL‐R null (LDL‐R knockout) mice (12–15 months old) were fed chow, Western diet (WD), WD with 4F, and WD with scramble peptide for 12 weeks. Serial echocardiography, cardiac catheterization, oxidized LDL assay, real‐time quantitative reverse transcription–polymerase chain reaction, and histological analysis were performed. The effect of LDL‐R knockdown and oxidized LDL on human pulmonary artery smooth muscle cell proliferation was assessed in vitro. LDL‐R and CD36 expression levels were significantly downregulated in the lungs of patients with PH. Patients with PH also had increased lung lipid deposits, oxidized LDL, E06 immunoreactivity, and plasma oxidized LDL/LDL ratio. LDL‐R knockout mice on WD developed PH, right ventricular hypertrophy, right ventricular dysfunction, pulmonary vascular remodeling, fibrosis, and lipid deposition in lungs, aortic atherosclerosis, and left ventricular dysfunction, which were prevented by 4F. Interestingly, PH in WD group preceded left ventricular dysfunction. Oxidized LDL or LDL‐R knockdown significantly increased proliferation of human pulmonary artery smooth muscle cells in vitro.

Conclusions

Human PH is associated with decreased LDL‐R in lungs and increased oxidized LDL in lungs and plasma. WD‐fed LDL‐R knockout mice develop PH and right ventricular dysfunction, implicating a role for LDL‐R and oxidized lipids in PH.

Prognostic role of traditional cardiovascular risk factors in patients with idiopathic pulmonary arterial hypertension

INTRODUCTION

Metabolic alterations have been recently associated with onset and progression of idiopathic pulmonary arterial hypertension (IPAH). We aimed to determine the prevalence and prognostic role of cardiovascular risk factors in patients with IPAH.

MATERIAL AND METHODS

Between February 2009 and January 2015 we recruited consecutive IPAH patients. Clinical assessment included medical history, fasting glucose, lipid profile, N-terminal pro-brain natriuretic peptide concentration, 6-minute walk test distance, WHO functional class and hemodynamic evaluation. Patients' risk was estimated based on the Swedish PAH Register grading system.

RESULTS

The study group included 61 IPAH patients, and the control group included 2413 Polish residents. When compared to the general population, IPAH patients had lower low-density lipoprotein cholesterol (LDL-C) and a higher triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio. Female patients were characterized by elevated glucose level, higher prevalence of diabetes and lower HDL-C than controls. PAH severity grade correlated positively with age and TG/HDL-C ratio (R = 0.29, p = 0.02) and inversely with LDL-C (R = -0.28, p = 0.03) and HDL-C (R = -0.39, p = 0.02) concentrations. After a follow-up of 48 (23-79) months we recorded 28 deaths in the IPAH group. In the regression analysis lower LDL-C (p = 0.002) and HDL-C (p = 0.0002) levels, and higher TG/HDL-C ratio (p = 0.003) and glucose level (p = 0.003) were associated with all-cause mortality after adjustment for age, sex or PAH severity grade.

CONCLUSIONS

Patients with IPAH are characterized by an altered profile of lipid and glucose metabolism. Lowered levels of LDL-C and HDL-C and increased TG/HDL-C ratio correlate with disease severity and together with elevated plasma glucose level predict poor survival in IPAH.

HDL Cholesterol as a Marker of Disease Severity and Prognosis in Patients with Pulmonary Arterial Hypertension

The impact of high-density lipoprotein (HDL) cholesterol on the development of atherosclerosis and diseases of systemic circulation has been well documented both in experimental and registry studies. Recent discoveries in pulmonary arterial hypertension (PAH) revealed a significant impact of HDL on pulmonary artery vasoreactivity and patients' prognosis. The vasoprotective activity of HDL primarily involves vascular endothelium that also plays a central role in pulmonary arterial hypertension (PAH) pathobiology. However, the exact mechanism in which this lipoprotein fraction exerts its effect in pulmonary circulation is still under investigation. This paper reviews potential vasoprotective mechanisms of HDL in pulmonary circulation and presents current clinical reports on the role of HDL in PAH patients.

New pathogenic variant of BMPR2 in pulmonary arterial hypertension

OBJECTIVES

The aim of this study was to evaluate the variant frequency of pulmonary arterial hypertension-related genes and provide theoretical basis for genetic screening of patients with pulmonary arterial hypertension further.

METHODS

Ten genes associated with pulmonary arterial hypertension were sequenced in 7 cases of idiopathic pulmonary arterial hypertension and 34 cases of congenital heart disease (CHD) associated with pulmonary arterial hypertension by next-generation high-throughput sequencing. Function prediction and gene variant amino acid conservation were carried out by bioinformatics software. Family study was performed on the patients with the variant.

RESULTS

A new bone morphogenetic protein receptor type 2(BMPR2) variant (c.344T&gt;C, p. F115S) was discovered in a girl who was diagnosed with idiopathic pulmonary arterial hypertension. Her second aunt and third aunt carried the same variant and were confirmed as patients with pulmonary arterial hypertension as well. No variants or single nucleotide polymorphisms were found in other pulmonary arterial hypertension-associated genes.

CONCLUSIONS

BMPR2 variant is the most common variant of pulmonary arterial hypertension. Genetic screening of BMPR2 variant and family survey in patients with pulmonary arterial hypertension is suggested for the sake of definite cause and better treatment.

Triglyceride-to-High-Density Lipoprotein Cholesterol Ratio and Systemic Inflammation in Patients with Idiopathic Pulmonary Arterial Hypertension

Background

Idiopathic pulmonary arterial hypertension (IPAH) patients are characterized by elevated triglyceride (TG)-to-HDL cholesterol (HDL-C) ratio, which has been proposed to be an important prognostic factor in this population. The mechanism of this phenomenon remains unknown. We therefore investigated the potential determinants of increased TG/HDL-C ratio in IPAH patients.

Material/Methods

We prospectively recruited consecutive clinically stable IPAH patients between January 2016 and February 2017. Patients with diabetes or using statins were excluded. Anthropometric measurements included body mass index (BMI) and skinfold thickness; body fat mass was calculated using age and sex-specific equations. We assessed lipid profile, homeostatic model assessment of insulin resistance (HOMA-IR), serum adipokine levels (adiponectin, resistin, leptin, and visfatin), and circulating cytokines (IL-1β, IL-6, MCP-1, and TNF-α).

Results

We assessed 47 IPAH patients: 9 of them had been diagnosed with diabetes and 10 were treated with statins; therefore, were excluded them from further analysis. Age, sex distribution, and BMI were similar irrespectively of TG/HDL-C ratio. Patients with increased TG/HDL-C ratio (>3) as compared to patients with TG/HDL-C ≤3 were characterized by higher levels of IL-1β, MCP-1, and IL-6. TG level was correlated with IL-1β (R=0.76, p<0.001), IL-6 (R=0.52, p=0.005), TNF-α (R=0.62, p<0.001), and MCP-1 (R=0.63, p<0.001). IL-1β was also inversely correlated with HDL-C (R=−0.44, p=0.02). We found no differences in concentration of fasting glucose, insulin, HOMA-IR, body fat content, or adipokine levels between patients with higher and lower TG/HDL-C ratios.

Conclusions

In IPAH patients, elevated TG/HDL-C ratio is a marker of systemic inflammation.

Cardiac Manifestations in Systemic Lupus Erythematosus: Clinical Correlates of Subclinical Echocardiographic Features

Objectives

This study aims to correlate subclinical echocardiographic features with the clinical, laboratory, and therapeutic profiles of the patients to characterize risks for systemic lupus erythematosus (SLE) cardiac diseases.

Methods

The study included 59 SLE patients. Demographic data, disease characteristics, and current therapies were recorded, and the anthropometric measurements and routine laboratory tests were performed. The disease activity by the SLE Disease Activity Index-2K (SLEDAI2K) and the presence of metabolic syndrome (MetS) were assessed. Two-dimensional echocardiography was performed.

Results

The mean age of the patients was 31.3 ± 10.5 years, and the disease duration was 5.18 ± 4.1 years. 86.4% of the patients were females. Cardiac presentations by echocardiography were mainly mitral regurgitation (33.9%), tricuspid regurgitation (32.2%), mitral thickening (18.6%), aortic thickening (13.6%), pericardial effusion (13.6%), and pulmonary hypertension (8.5%) in order of frequency. The frequency of different echocardiographic findings with respect to other clinical phenotypes showed peaks with renal disease, MetS, and leukopenia. Components of MetS (triglycerides, high systolic blood pressure) and avascular necrosis were significant predictors for pericardial diseases (OR=1.011 CI 95% 1-1.022, p=0.046, OR=1.157 CI 95% 1.025-1.307, p=0.018, and OR=74.78 CI 95% 2.52-2215.76, p=0.013, respectively), and it is likely that hydroxychloroquine was protective against them. Age of the patients was a significant predictor for tricuspid regurgitation (OR=1.063 CI 95% 1.004-1.126, p=0.036). Mucosal ulcers were negative predictors for mitral thickening and regurgitation (OR=0.2 CI 95% 0.059-0.673, p=0.009). The use of corticosteroids appeared to protect against a number of valve lesions especially tricuspid regurgitation (OR=0.299 CI 95% 0.088-1.019, p=0.054).

Conclusion

This study highlighted different echocardiographic features and identified clinical predictors of different cardiac pathologies aiming to determine patients at risk and improve the prognosis of SLE cardiac diseases.

Cholesterol Regulation of Pulmonary Endothelial Calcium Homeostasis

Cholesterol is a key structural component and regulator of lipid raft signaling platforms critical for cell function. Such regulation may involve changes in the biophysical properties of lipid microdomains or direct protein-sterol interactions that alter the function of ion channels, receptors, enzymes, and membrane structural proteins. Recent studies have implicated abnormal membrane cholesterol levels in mediating endothelial dysfunction that is characteristic of pulmonary hypertensive disorders, including that resulting from long-term exposure to hypoxia. Endothelial dysfunction in this setting is characterized by impaired pulmonary endothelial calcium entry and an associated imbalance that favors production vasoconstrictor and mitogenic factors that contribute to pulmonary hypertension. Here we review current knowledge of cholesterol regulation of pulmonary endothelial Ca²⁺ homeostasis, focusing on the role of membrane cholesterol in mediating agonist-induced Ca²⁺ entry and its components in the normal and hypertensive pulmonary circulation.

Pulmonary vascular dysfunction in metabolic syndrome

Metabolic syndrome is a critically important precursor to the onset of many diseases, such as cardiovascular disease, and cardiovascular disease is the leading cause of death worldwide. The primary risk factors of metabolic syndrome include hyperglycaemia, abdominal obesity, dyslipidaemia, and high blood pressure. It has been well documented that metabolic syndrome alters vascular endothelial and smooth muscle cell functions in the heart, brain, kidney and peripheral vessels. However, there is less information available regarding how metabolic syndrome can affect pulmonary vascular function and ultimately increase an individual's risk of developing various pulmonary vascular diseases, such as pulmonary hypertension. Here, we review in detail how metabolic syndrome affects pulmonary vascular function.

Right atrium enlargement predicts clinically significant supraventricular arrhythmia in patients with pulmonary arterial hypertension

BACKGROUND

Right atrial (RA) enlargement is a common finding in patients with pulmonary arterial hypertension (PAH) and an important predictor of mortality, however its relation to the risk of atrial arrhythmias has not been assessed.

OBJECTIVES

To assess whether RA enlargement is associated with supraventricular arrhythmias (SVA) and whether it predicts new clinically significant SVA (csSVA).

METHODS

Patients with PAH were recruited between January 2010 and December 2014 and followed until January 2017. csSVA was diagnosed if it resulted in hospitalization. To assess predictors of new csSVA, only patients without a history of SVA at baseline were analyzed.

RESULTS

Among 97 patients, any SVA was observed in 45 (46.4%) and included permanent atrial fibrillation(AF, n = 8), paroxysmal AF (n = 10), permanent atrial flutter (AFl, n = 1), paroxysmal AFl (n = 2) or other types of supraventricular tachycardia (n = 24). Patients with SVA as compared to patients without SVA were characterized by older age, lower distance in a 6-minute test, higher NT-proBNP, higher RA area index (RAai), left atrial area index, mean right atrial pressure (mRAP) and were more commonly treated with β-blocker. Eighty five patients who were in sinus rhythm at baseline assessment and had no history of significant SVA were observed for 37 ± 19.9 months. During that time csSVA occurred in 15.3%. In univariate models, the occurrence of csSVA were predicted by age, right ventricular ejection fraction, right ventricular end diastolic index, RAai and mRAP, but in multivariate model only RAai remained significant predictor for csSVA (HR of 1.23, 95%CI: 1.11-1.36, p < 0.001). The optimal threshold for RA enlargement as discriminator of csSVA was 21.7 cm2/m2.

CONCLUSIONS

In PAH patients RA enlargement is associated with increased prevalence of SVA. RAai is an independent predictor of hospitalization due to csSVA.