Pulmonary hypertension: diagnosis and management

Clinical Utility of Bronchoalveolar Lavage Neutrophilia and Biomarkers for Evaluating Severity of Chronic Fibrosing Interstitial Lung Diseases

Introduction It is hypothesized that bronchoalveolar lavage (BAL) neutrophilia, Krebs von den Lungen-6 (KL-6), and C-reactive protein (CRP) predict the severity of chronic fibrosing interstitial lung diseases (CF-ILDs). Methods This cross-sectional study enrolled 30 CF-ILD patients. Using Pearson's correlation analysis, BAL neutrophils, KL-6, and CRP were correlated with forced vital capacity (FVC), diffusing lung capacity for carbon monoxide (DLCO), six-minute walk distance (6MWD), partial pressure of oxygen (PaO2), computed tomography fibrosis score (CTFS), and pulmonary artery systolic pressure (PASP). Using the receiver operator characteristic (ROC) curve, BAL KL-6 and CRP were evaluated against FVC% and DLCO% in isolation and combination with BAL neutrophilia for predicting the severity of CF-ILDs. Results BAL neutrophilia significantly correlated only with FVC% (r = -0.38, P = 0.04) and DLCO% (r = -0.43, P = 0.03). BAL KL-6 showed a good correlation with FVC% (r = -0.44, P < 0.05) and DLCO% (r = -0.50, P = 0.02), while BAL CRP poorly correlated with all parameters (r = 0.0-0.2). Subset analysis of BAL CRP in patients with CTFS ≤ 15 showed a better association with FVC% (r = -0.28, P = 0.05) and DLCO% (r = -0.36, P = 0.04). BAL KL-6 cut-off ≥ 72.32 U/ml and BAL CRP ≥ 14.55 mg/L predicted severe disease with area under the curve (AUC) values of 0.77 and 0.71, respectively. The combination of BAL neutrophilia, KL-6, and CRP predicted severity with an AUC value of 0.89. Conclusion The combination of BAL neutrophilia, KL-6, and CRP facilitates the severity stratification of CF-ILDs complementing existing severity parameters.

Endothelial dysfunction in patients with systemic sclerosis

Introduction

Patients with systemic sclerosis experience endothelial dysfunction and damage even in the absence of clinical manifestations.

Aim

To evaluate various methods for assessing the endothelial function for their applicability to clinical practice.

Material and methods

Forty-two patients (7 men and 35 women) with systemic sclerosis and 36 controls (11 men and 25 women) matched for age, sex, body mass index, smoking habit, and comorbidities were enrolled in the study. We assessed each participant for typical risk factors for cardiovascular diseases and measured serum levels of vascular cell adhesion molecule-1 (VCAM-1) and thrombomodulin together with flow-mediated dilatation (FMD) of the brachial artery and intima-media thickness (IMT) of the common carotid artery using ultrasonography.

Results

Patients with systemic sclerosis did not differ from controls in serum levels of VCAM-1 and thrombomodulin, however, the statistical analysis with adjustment for potential confounders revealed increased levels of thrombomodulin in the patients (p = 0.03). They also had a 45% lower relative increase of FMD (FMD%), and 13% higher IMT (p < 0.01, both, also after adjustment for potential confounders). In a simple regression model, lower FMD% was determined by age (β = –0.57, 95% confidence interval (CI): –0.72 to –0.43) and C-reactive protein levels (β = –0.38, 95% CI: –0.55 to –0.22). Thicker IMT was related to age (β = 0.64, 95% CI: 0.52–0.67), glomerular filtration rate (β = –0.34, 95% CI: –0.5 to –0.18), and blood thrombomodulin levels (β = 0.45, 95% CI: 0.13–0.76).

Conclusions

Patients with systemic sclerosis present with endothelial dysfunction which may be detected using ultrasonographic methods. The exact mechanism of observed abnormalities is unknown, but it is possibly related to the chronic inflammation and ischemia-reperfusion injury.

The practical management of fluid retention in adults with right heart failure due to pulmonary arterial hypertension

Our aim with this review is to provide practical advice and management support for nurses and other healthcare practitioners in managing fluid retention in adults with right heart failure (RHF) due to pulmonary arterial hypertension (PAH). Vigilant management of RHF is important for maintaining patient quality of life, as fluid overload can lead to abdominal bloating (ascites) and peripheral oedema, which also has a major impact on patients' morbidity and mortality. Patients with RHF should be assessed regularly for signs of fluid retention. If fluid overload develops, it is important to determine whether it is caused by the progression of PAH, a side effect of PAH-specific treatment, or another drug or comorbid condition, as this affects both the prognosis and the management strategy. Right heart failure can be treated with both pharmacological and non-pharmacological interventions to reduce fluid retention; including altering fluid and salt intake, weight monitoring, and use of diuretics. All patients on diuretics should be regularly monitored for renal dysfunction and electrolyte imbalance and given advice on how to manage the side effects associated with diuretic use. Fluid retention is often assessed and treated in clinical practice by specialist nurses, who act as a key patient contact providing advice and information on symptom management. This review provides an overview of the challenges related to fluid retention, including strategies to help patients manage symptoms and side effects of treatment.

Schistosomiasis-associated pulmonary arterial hypertension: survival in endemic area in Brazil

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The PHC registry equation accurately predicted survival in Sch-PAH patients.

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Sch-PAH survival cannot be safely predicted using only validated clinical variables only.

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Survival studies in endemic regions of Schistosomiasis are needed to establish the real prognosis of Sch-PAH in the world.

Background

The survival of schistosomiasis-associated pulmonary arterial hypertension (Sch-PAH) patients in endemic areas is unknown, but can be estimated using predictive equations.

Methods

We retrospectively analyzed all consecutive patients diagnosed with Sch-PAH referred to the Pronto SocorroCardiologico de Pernambuco between 2004 and 2010 using specific therapy and measured laboratory, diagnostic imaging, and baseline hemodynamic parameters. Observed and predicted survivals according to the National Institutes of Health (NIH) and Pulmonary Hypertension Connection (PHC) registry equations were compared by the Kaplan–Meier method, log-rank test and Cox proportional hazards model.

Results

Sixty-eight patients (47 [69.1%] women) observed for a mean of 3.1 years (range, 7–72 months), median survival was 74 months, and 42 (61.7%) survived. The sex and age distributions were similar for functional class I/II and III/IV patients. Hemodynamic abnormalities were severe: mean right atrial pressure, 12.6 ± 6.2 mmHg; mean pulmonary artery pressure, 60.3 ± 13.69 mmHg; pulmonary vascular resistance, 14.62 ± 7.04 Wood units; and cardiac index, 2.3 ± 0.8 L/min/m². The usual idiopathic PAH predictors were not prognostic in Sch-PAH patients. The 1-, 3- and 5-year survival rates were 92.1%, 75.2%, and 50.8%, respectively, and those estimatedby the NIH and PHC registry equations were 68%, 45% and 32% (p = 0.001), and 93%, 79% and 68% (p = 0.340), respectively.

Conclusions

Sch-PAH patients in endemic areas have severe hemodynamic profiles and reduced long-term survivaldespite treatment. The PHC registry equation may be a useful tool to estimate survival in Sch-PAH.

The transient receptor potential vanilloid-3 regulates hypoxia-mediated pulmonary artery smooth muscle cells proliferation via PI3K/AKT signaling pathway

OBJECTVES

Transient receptor potential vanilloid 3 (TRPV3) is a member of the TRP channels family of Ca²⁺ -permeant cation channels. In this study, we aim to investigate the role of TRPV3 in pulmonary vascular remodeling and PASMCs proliferation under hypoxia.

MATERIALS AND METHODS

The expression of TRPV3 was evaluated in patients with pulmonary arterial hypertension (PAH) and hypoxic rats, using hematoxylin and eosin (H&E) and immunohistochemistry. In vitro, MTT assay, flow cytometry, Western blotting and immunofluorescence were performed to investigate the effects of TRPV3 on proliferation of PASMCs.

RESULTS

We found that, in vivo, the expression of TRPV3 was increased in patients with PAH and hypoxic rats. Right ventricular hypertrophy measurements and pulmonary pathomorphology data show that the ratio of the heart weight/tibia length (HW/TL), the right ventricle/left ventricle plus septum (RV/LV+S) and the medial width of the pulmonary artery were increased in chronic hypoxic rats. Moreover, the expression of proliferating cell nuclear antigen (PCNA), Cyclin D, Cyclin E and Cyclin A, phospho-CaMKII (p-CaMKII) were induced by hypoxia. In vitro, we revealed that hypoxia promoted PASMCs viability, increased the expression of PCNA, Cyclin D, Cyclin E, Cyclin A p-CaMKII, made more cells from G₀ /G₁ phase to G₂ /M + S phase, enhanced the microtubule formation, and increased [Ca²⁺ ]_i , which could be suppressed by Ruthenium Red, an inhibitor of TRPV3, and TRPV3 silencing has similar effects. Furthermore, the up-regulated expression of PCNA, Cyclin D, Cyclin E and Cyclin A, the increased number of cells in G₂ /M and S phase, and the enhanced activation and expression of PI3K and AKT proteins induced by hypoxia and in presence of carvacrol (an agonist of TRPV3), was significantly attenuated by incubation of LY 294002, a specific inhibitor for PI3K/AKT.

CONCLUSIONS

These findings suggest that TRPV3 is involved in hypoxia-induced pulmonary vascular remodeling and promotes proliferation of PASMCs and the effect is, at least in part, mediated via the PI3K/AKT pathway.

Syncope and the risk of sudden cardiac death: Evaluation, management, and prevention

Syncope is a clinical syndrome defined as a relatively brief self-limited transient loss of consciousness (TLOC) caused by a period of inadequate cerebral nutrient flow. Most often the trigger is an abrupt drop of systemic blood pressure. True syncope must be distinguished from other common non-syncope conditions in which real or apparent TLOC may occur such as seizures, concussions, or accidental falls. The causes of syncope are diverse, but in most instances, are relatively benign (e.g., reflex and orthostatic faints) with the main risks being accidents and/or injury. However, in some instances, syncope may be due to more worrisome conditions (particularly those associated with cardiac structural disease or channelopathies); in such circumstances, syncope may be an indicator of increased morbidity and mortality risk, including sudden cardiac death (SCD). Establishing an accurate basis for the etiology of syncope is crucial in order to initiate effective therapy. In this review, we focus primarily on the causes of syncope that are associated with increased SCD risk (i.e., sudden arrhythmic cardiac death), and the management of these patients. In addition, we discuss the limitations of our understanding of SCD in relation to syncope, and propose future studies that may ultimately address how to improve outcomes of syncope patients and reduce SCD risk.

Pediatric Perioperative Pulmonary Arterial Hypertension: A Case-Based Primer

The perioperative period is an extremely tenuous time for the pediatric patient with pulmonary arterial hypertension. This article will discuss a multidisciplinary approach to preoperative planning, the importance of early identification of pulmonary hypertensive crises, and practical strategies for postoperative management for this unique group of children.

Cardiovascular mechanics in the early stages of pulmonary hypertension: a computational study

We formulate and study a new mathematical model of pulmonary hypertension. Based on principles of fluid and elastic dynamics, we introduce a model that quantifies the stiffening of pulmonary vasculature (arteries and arterioles) to reproduce the hemodynamics of the pulmonary system, including physiologically consistent dependence between compliance and resistance. This pulmonary model is embedded in a closed-loop network of the major vessels in the body, approximated as one-dimensional elastic tubes, and zero-dimensional models for the heart and other organs. Increasingly severe pulmonary hypertension is modeled in the context of two extreme scenarios: (1) no cardiac compensation and (2) compensation to achieve constant cardiac output. Simulations from the computational model are used to estimate cardiac workload, as well as pressure and flow traces at several locations. We also quantify the sensitivity of several diagnostic indicators to the progression of pulmonary arterial stiffening. Simulation results indicate that pulmonary pulse pressure, pulmonary vascular compliance, pulmonary RC time, luminal distensibility of the pulmonary artery, and pulmonary vascular impedance are much better suited to detect the early stages of pulmonary hypertension than mean pulmonary arterial pressure and pulmonary vascular resistance, which are conventionally employed as diagnostic indicators for this disease.

Chemical and biological assessment of metal organic frameworks (MOFs) in pulmonary cells and in an acute in vivo model: relevance to pulmonary arterial hypertension therapy

Pulmonary arterial hypertension (PAH) is a progressive and debilitating condition. Despite promoting vasodilation, current drugs have a therapeutic window within which they are limited by systemic side effects. Nanomedicine uses nanoparticles to improve drug delivery and/or reduce side effects. We hypothesize that this approach could be used to deliver PAH drugs avoiding the systemic circulation. Here we report the use of iron metal organic framework (MOF) MIL-89 and PEGylated MIL-89 (MIL-89 PEG) as suitable carriers for PAH drugs. We assessed their effects on viability and inflammatory responses in a wide range of lung cells including endothelial cells grown from blood of donors with/without PAH. Both MOFs conformed to the predicted structures with MIL-89 PEG being more stable at room temperature. At concentrations up to 10 or 30 µg/mL, toxicity was only seen in pulmonary artery smooth muscle cells where both MOFs reduced cell viability and CXCL8 release. In endothelial cells from both control donors and PAH patients, both preparations inhibited the release of CXCL8 and endothelin-1 and in macrophages inhibited inducible nitric oxide synthase activity. Finally, MIL-89 was well-tolerated and accumulated in the rat lungs when given in vivo. Thus, the prototypes MIL-89 and MIL-89 PEG with core capacity suitable to accommodate PAH drugs are relatively non-toxic and may have the added advantage of being anti-inflammatory and reducing the release of endothelin-1. These data are consistent with the idea that these materials may not only be useful as drug carriers in PAH but also offer some therapeutic benefit in their own right.

Pulmonary Hypertension - New Trends of Diagnostic and Therapy

Pulmonary hypertension is a pathophysiological state hemodynamically defined as the increase of the mean pulmonary arterial pressure above 25, or 30 mmHg at rest, measured by catheterization of the right heart. Laboratory findings usually reveals polycythemia, the ECG right ventricle hypertrophy, and x-ray characteristic of diseased branches (echocardiography and biomarkers such as B-type natriuretic peptide (BNP) and N-terminal pro-BNP hormones are potentially helpful tools in identifying PH). Echocardiography can be found the increase of the right atrium and ventricle, right ventricular hypertrophy, abnormal contraction of the interventricular septum, left ventricular diastolic dysfunction and decreased left ventricular size, with reduced volumes of systole and end diastole. Doppler confirming tricuspid regurgitation. Pharmacological therapy would represent a use: Calcium Channel Blockers, Prostacyclin Analogues, Endothelin Receptor Antagonists and Phosphodiesterase-5 Inhibitors. Alpha adrenergic antagonists, endothelial receptor subtype A (Bosentan, Tracller) with treatment of the underlying disease or anticongestive therapy, are recommended. In case of inadequate response to treatment with a specific drug, guidelines recommend the combined use of drugs from the basic three groups, using their synergism.

Impact of age on pulmonary artery systolic pressures at rest and with exercise

AIM

It is not well known if advancing age influences normal rest or exercise pulmonary artery pressures. The purpose of the study was to evaluate the association of increasing age with measurements of pulmonary artery systolic pressure at rest and with exercise.

SUBJECTS AND METHODS

A total of 467 adults without cardiopulmonary disease and normal exercise capacity (age range: 18-85 years) underwent symptom-limited treadmill exercise testing with Doppler measurement of rest and exercise pulmonary artery systolic pressure.

RESULTS

There was a progressive increase in rest and exercise pulmonary artery pressures with increasing age. Pulmonary artery systolic pressures at rest and with exercise were 25±5mmHg and 33±9mmHg, respectively, in those <40 years, and 30±5mmHg and 41±12mmHg, respectively, in those ≥70 years. While elevated left-sided cardiac filling pressures were excluded by protocol design, markers of arterial stiffness associated with the age-dependent effects on pulmonary pressures.

CONCLUSION

These data demonstrate that in echocardiographically normal adults, pulmonary artery systolic pressure increases with advancing age. This increase is seen at rest and with exercise. These increases in pulmonary pressure occur in association with decreasing transpulmonary flow and increases in systemic pulse pressure, suggesting that age-associated blood vessel stiffening may contribute to these differences in pulmonary artery systolic pressure.

Arterial-ventricular and interventricular interaction in isolated post-capillary and combined pulmonary hypertension in severe mitral stenosis

BACKGROUND

Isolated post-capillary pulmonary hypertension (Ipc-PH) is characterized by elevated left atrial pressures that are passively transmitted upstream, whereas combined pre- and post-capillary PH (Cpc-PH) demonstrates additional reactive changes in pulmonary vasculature. The increased load imposed on the right ventricle (RV) influences left ventricular (LV) mechanics by means of interventricular interaction. However, there is lack of evidence to substantiate the effect of possible additional alterations in the arterio-ventricular (AV) coupling and their effect on LV function. Considering the discrepant RV load in Cpc-PH and Ipc-PH, we sought to investigate whether these two conditions are also characterized by differential alterations in AV coupling.

METHODS AND RESULTS

Invasive hemodynamic and echocardiographic data of 120 patients with PH due to severe rheumatic mitral stenosis before and immediately after percutaneous valvulotomy, along with 40 age-matched healthy controls, were analyzed. Effective arterial (E a) and ventricular elastance (E es) were measured. PH patients demonstrated elevated LV afterload (E a) along with AV uncoupling, and these derangements were more evident in the Cpc-PH group [E a: 3.3 (2.3-5.4) vs 2.6 (2.1-3.5) mmHg/mL, E a/E es: 0.73 (0.6-0.9) vs 0.88 (0.7-1.2), p < 0.05]. In addition, PH was associated with reduced LV deformation, which was mainly determined by elevated E a, while the effect of interventricular interaction was limited to the septal wall.

CONCLUSIONS

Our results suggest that in addition to the interventricular interaction, an abnormal AV coupling contributes to the altered LV mechanics that has been associated with adverse prognosis in Cpc-PH.

The Relationship of Fluid Overload as Assessed by Bioelectrical Impedance Analysis with Pulmonary Arterial Hypertension in Hemodialysis Patients

Background

Pulmonary arterial hypertension (PAH) is common disease among hemodialysis (HD) patients and is associated with increased morbidity and mortality. However, its pathogenesis has not been completely elucidated. We aimed to evaluate the frequency of PAH in HD patients, as well as the relationship between fluid status and PAH.

Material/Methods

We enrolled 77 HD patients in this study. Multifrequency bioimpedance analysis (BIA) was used to assess fluid status. BIA was performed before and 30 min after the midweek of HD. Overhydration (OH)/extracellular water (ECW)% ratio was used as an indicator of fluid status. Fluid overload was defined as OH/ECW ≥7%. Echocardiographic examinations were performed before and after the HD. Pulmonary arterial hypertension was defined as systolic pulmonary artery pressure at rest (sPAP) higher than 35 mmHg.

Results

PAH was found in 33.7% of the HD patients. OH/ECW and the frequency of fluid overload were significantly higher in HD patients with PAH than those without PAH, whereas serum albumin and hemoglobin levels were significantly lower. sPAP level was significantly higher in HD patients with fluid overload than in those without fluid overload after hemodialysis session. Furthermore, sPAP, OH/ECW levels, and the frequency of PAH were significantly reduced after HD. We also found a significant positive correlation between sPAP and OH/ECW. Multivariate logistic regression analysis demonstrated fluid overload to be an independent predictor of PAH after HD.

Conclusions

PAH is prevalent among HD patients. This study demonstrated a strong relationship between fluid overload and PAH in HD patients.

Survival in an incident cohort of patients with pulmonary arterial hypertension in Denmark

We aimed to characterize and estimate survival rates in patients diagnosed with pulmonary arterial hypertension (PAH) in western Denmark in the modern management era. All incident cases of PAH were consecutively enrolled in our single-center prospective cohort study between January 2000 and March 2012. A total of 134 patients fulfilling the inclusion criteria were followed up from first diagnostic right heart catheterization to either death or the end of the study. Kaplan-Meier survival analysis was used to estimate 1-, 3-, and 5-year survival rates with 95% confidence intervals (CIs). Survival in the total cohort was 86.4% (95% CI, 79.3%-91.2%) after 1 year, 72.9% (95% CI, 64.1%-79.9%) after 3 years, and 65.4% (95% CI, 55.8%-73.4%) after 5 years. Significantly better survival was seen in the group of patients with PAH associated with congenital heart disease than in the group of patients with idiopathic PAH, heritable PAH, connective tissue disease, HIV infection, and portal hypertension. In conclusion, survival rates in the Danish PAH population were similar to or slightly better than survival rates estimated in other modern registries. However, PAH remains a fatal disease, despite modern targeted therapies.

Fasudil and SOD packaged in peptide-studded-liposomes: Properties, pharmacokinetics and ex-vivo targeting to isolated perfused rat lungs

The present study investigated the feasibility of encapsulating two drugs, fasudil and superoxide dismutase (SOD), into liposomes for targeted and inhalational delivery to the pulmonary vasculature to treat pulmonary arterial hypertension (PAH). Nanosized liposomes were prepared by a thin-film formation and extrusion method, and the drugs were encapsulated by a modified freeze-thaw technique. The peptide CARSKNKDC (CAR), a pulmonary-specific targeting sequence, was conjugated on the surface of liposomes. Formulations were optimized for various physicochemical properties, tested for their ex-vivo and in-vivo drug absorption after intratracheal administration, and evaluated for short-term safety in healthy rats. The homogenous nanosized liposomes contained both SOD (~55% entrapment) and fasudil (~40% entrapment), and were stable at 4°C and after nebulization. Liposomes released the drugs in a controlled-release fashion. Compared with plain liposomes, CAR-liposomes increased the uptake by pulmonary endothelial and smooth muscle cells by ~2-fold. CAR-liposomes extended the biological half-lives of SOD and fasudil by ~3-fold. Ex-vivo studies demonstrated that CAR-liposomes were better retained in the lungs than plain liposomes. Bronchoalveolar lavage studies indicated the safety of peptide-equipped liposomes as pulmonary delivery carriers. Overall, this study demonstrates that CAR-liposomes may be used as inhalational carriers for SOD plus fasudil-based combination therapy for PAH.

Hemodynamic changes of the middle hepatic vein in patients with pulmonary hypertension using echocardiography

The aim of this study was to analyze the changes of the middle hepatic vein (MHV) spectra in patients with pulmonary hypertension (PH) caused by congenital heart disease (CHD) and determine the proper parameters of MHV to predict PH. Eighty patients with CHD were included, whose pulmonary artery pressure was measured via right heart catheterization, and the MHV spectra were detected via echocardiography. The peak value of velocity (V) and velocity time integral (VTI) of the waves, including S wave, D wave and A wave, were measured at the end of inspiration. The values of the MHV parameters that were predictive of PH were evaluated and their cut-off points were determined. Compared with the control group, V of S wave (S), VTI of S wave (SVTI), V of D wave (D), VTI of D wave (DVTI) decreased and V of A wave (A), VTI of A wave (AVTI), A/S, AVTI/SVTI, A/(S+D), AVTI/ (SVTI+DVTI) increased in the PH group. These differences were statistically significant (P<0.05). A correlation analysis determined that the ratios of A/S, A/(S+D), AVTI/(SVTI+DVTI) were positively correlated with pulmonary artery mean pressure (r=0.529,0.575,0.438,P<0.001). An ROC curve analysis determined that the diagnostic effect of A/(S+D) was superior to the other two parameters. On the ROC curve, when the ratio of A/(S+D) was 0.30, the sensitivity was 85.37% and specificity was 75.00% for predicting PH. The spectral parameters of MHV, including the ratios of A/S, A/(S+D) and AVTI/(SVTI+DVTI), increased with increasing pulmonary pressure in CHD patients. When the ratio of A/(S+D) was 0.30 in MHV spectra, it had sufficient sensitivity and specificity for diagnosing PH, and this method could be used as a new non-invasive complementary echocardiographic parameter for predicting PH.

The economic burden of pulmonary arterial hypertension (PAH) in the US on payers and patients

BACKGROUND

Pulmonary arterial hypertension (PAH) is a rare condition that can ultimately lead to right heart failure and death. In this study we estimated the health care costs and resource utilization associated with PAH in a large US managed care health plan.

METHODS

Subjects with claims-based evidence of PAH from 1/1/2004 to 6/30/2010 (identification period) were selected. To be included in the final PAH study sample, subjects were required to have ≥2 claims with a primary PH diagnosis; ≥2 claims with a PAH related-diagnosis (connective tissue diseases, congenital heart diseases, portal hypertension); and ≥1 claim with evidence of a PAH-indicated medication. The earliest date of a claim with evidence of PAH-indicated medication during the identification period was set as the index date. Health care costs and resource utilization were compared between an annualized baseline period and a 12 month follow-up period.

RESULTS

504 PAH subjects were selected for the final study cohort. Estimated average total health care costs were approximately 16% lower in the follow-up period compared to the baseline period (follow-up costs = $98,243 [SD = 110,615] vs. baseline costs = $116,681 [SD = 368,094], p < 0.001), but substantively high in each period relative to costs reported for other chronic diseases. Pharmacy costs were significantly higher in the follow-up period vs. the baseline period, ($38,514 [SD = 34,817] vs. $6,440 [SD = 12,186], p < 0.001) but medical costs were significantly lower in the follow-up vs. baseline ($59,729 [SD = 106,683] vs. $110,241 [SD = 368,725], p < 0.001). These costs were mirrored in health-care resource utilization estimates. The average counts of ambulatory visits and inpatient stays were lower in the follow-up vs. the baseline (both p < 0.001). Results varied in exploratory analyses when less restrictive subject identification algorithms were used.

CONCLUSIONS

Subjects with evidence of PAH had substantively high health care costs. Medical costs appeared to decrease following PAH medication use, but with a concomitant increase in pharmacy costs.

The potential efficacy of R8-modified paclitaxel-loaded liposomes on pulmonary arterial hypertension

PURPOSE

In this paper, a novel liposomal formulation of paclitaxel modified with octaarginine (R8) was fabricated and the therapeutic efficacy of it on pulmonary arterial hypertension was evaluated.

METHODS

Octaarginine-modified stealth liposomes loaded with PTX (R8-PTX-LIP) were prepared and characterized. Vector cytoxicity and anti-proliferation ability of different formulations on primary cultured VSMCs were determined with MTT assay. The uptake capacity of VSMCs on different formulations were evaluated by flow cytometry, and the influences on cytoskeletons of liposomes were investigated by cytoskeleton staining with rhodamine-phalloidin. The biodistribution of liposomes were imaged by a CCD camera using a near-infrared fluorophore DiD. The therapeutic efficacy of different PTX-formulations of PAH was evaluated by hemodynamic measurement, right ventricular hypertrophic parameters and vessel diameters.

RESULTS

The cellular uptake of R8 modified liposomes (R8-LIP) was improved noticeably compared with other groups. All liposomes did not exert cytotoxicity on VSMCs in 24 h. R8-PTX-LIP exhibited the strongest inhibitory effect on the proliferation of VSMCs among all the formulations (p < 0.001). R8-PTX-LIP could reverse the phenotype transformation, and inhibit cell migration. mPAP, (RV/LV+S) and the wall thickness of small distal pulmonary arteries of rats treated with R8-PTX-LIP were significantly lower than those from other groups (p < 0.001).

CONCLUSIONS

In conclusion, the drug delivery system of R8-modified paclitaxel-loaded liposomes we established showed pronounced inhibitory effect over VSMCs proliferation and cytoskeleton formation in vitro, a stronger pulmonary delivery ability in vivo, and was effective on PAH, showing the potential for pulmonary drug delivery system for PAH treatment.

Considerations for numerical modeling of the pulmonary circulation--a review with a focus on pulmonary hypertension

Both in academic research and in clinical settings, virtual simulation of the cardiovascular system can be used to rapidly assess complex multivariable interactions between blood vessels, blood flow, and the heart. Moreover, metrics that can only be predicted with computational simulations (e.g., mechanical wall stress, oscillatory shear index, etc.) can be used to assess disease progression, for presurgical planning, and for interventional outcomes. Because the pulmonary vasculature is susceptible to a wide range of pathologies that directly impact and are affected by the hemodynamics (e.g., pulmonary hypertension), the ability to develop numerical models of pulmonary blood flow can be invaluable to the clinical scientist. Pulmonary hypertension is a devastating disease that can directly benefit from computational hemodynamics when used for diagnosis and basic research. In the present work, we provide a clinical overview of pulmonary hypertension with a focus on the hemodynamics, current treatments, and their limitations. Even with a rich history in computational modeling of the human circulation, hemodynamics in the pulmonary vasculature remains largely unexplored. Thus, we review the tasks involved in developing a computational model of pulmonary blood flow, namely vasculature reconstruction, meshing, and boundary conditions. We also address how inconsistencies between models can result in drastically different flow solutions and suggest avenues for future research opportunities. In its current state, the interpretation of this modeling technology can be subjective in a research environment and impractical for clinical practice. Therefore, considerations must be taken into account to make modeling reliable and reproducible in a laboratory setting and amenable to the vascular clinic. Finally, we discuss relevant existing models and how they have been used to gain insight into cardiopulmonary physiology and pathology.

Bloodstream infections in patients with pulmonary arterial hypertension treated with intravenous prostanoids: insights from the REVEAL REGISTRY®

OBJECTIVE

To evaluate the rate of and potential risk factors for bloodstream infections (BSIs) using data from the REVEAL (Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension [PAH] Disease Management) REGISTRY(®), which provides current information about patients with PAH.

PATIENTS AND METHODS

Patients were enrolled from March 30, 2006, through December 8, 2009, and data on reported BSIs were collected through the third quarter of 2010. Bloodstream infection rates were calculated per 1000 patient-days of risk.

RESULTS

Of 3518 patients enrolled, 1146 patients received intravenous (IV) prostanoid therapy for more than 1 day (no BSI, n=1023; ≥1 BSI, n=123; total BSI episodes, n=166). Bloodstream infections rates were significantly increased in patients receiving IV treprostinil vs IV epoprostenol (0.36 vs 0.12 per 1000 treatment days; P<.001), primarily due to gram-negative organisms (0.20 vs 0.03 per 1000 treatment days; P<.001). Multivariate analysis adjusting for age, causes of PAH, and year of BSI found that treatment with IV treprostinil was associated with a 3.08-fold increase (95% confidence interval, 2.05-4.62; P<.001) in BSIs of any type and a 6.86-fold increase (95% confidence interval, 3.60-13.07; P<.001) in gram-negative BSIs compared with treatment with IV epoprostenol.

CONCLUSION

Compared with IV epoprostenol therapy, treatment with IV treprostinil is associated with a significantly higher rate of gram-negative BSIs; observed differences in BSI rate did not seem to be due to any other analyzed factors.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00370214.

Clinical perspectives with long-term pulsed inhaled nitric oxide for the treatment of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a chronic, progressive disease of the pulmonary vasculature with a high morbidity and mortality. Its pathobiology involves at least three interacting pathways – prostacyclin (PGI₂), endothelin, and nitric oxide (NO). Current treatments target these three pathways utilizing PGI₂ and its analogs, endothelin receptor antagonists, and phosphodiesterase type-5 (PDE-5) inhibitors. Inhaled nitric oxide (iNO) is approved for the treatment of hypoxic respiratory failure associated with pulmonary hypertension in term/near-term neonates. As a selective pulmonary vasodilator, iNO can acutely decrease pulmonary artery pressure and pulmonary vascular resistance without affecting cardiac index or systemic vascular resistance. In addition to delivery via the endotracheal tube, iNO can also be administered as continuous inhalation via a facemask or a pulsed nasal delivery. Consistent with a deficiency in endogenously produced NO, long-term pulsed iNO dosing appears to favorably affect hemodynamics in PAH patients, observations that appear to correlate with benefit in uncontrolled settings. Clinical studies and case reports involving patients receiving long-term continuous pulsed iNO have shown minimal risk in terms of adverse events, changes in methemoglobin levels, and detectable exhaled or ambient NO or NO₂. Advances in gas delivery technology and strategies to optimize iNO dosing may enable broad-scale application to long-term treatment of chronic diseases such as PAH.

Pulmonary arterial hypertension in the setting of pregnancy: a case series and standard treatment approach

Pregnancy in patients with pulmonary arterial hypertension (PAH) is associated with a maternal mortality of 30-50% despite modern treatment modalities. The majority of maternal deaths in PAH patients occur either during labor and delivery or within 1 month postpartum. Cardiovascular collapse is attributed to a mismatch between the physiologic limitations of PAH and the changes that occur with pregnancy and delivery. In the Unites States, there is no consensus on the management of PAH in pregnancy. Several case reports have been published describing improved maternal-fetal outcomes, likely due to new advanced PH therapies, earlier diagnosis of PAH, and an adoption of a multidisciplinary treatment approach. We present five cases of gravid PAH patients successfully managed at our institution with a description of our standardized multidisciplinary treatment approach.

Overview of current therapeutic approaches for pulmonary hypertension

There have been tremendous strides in the management of pulmonary hypertension over the past 20 years with the introduction of targeted medical therapies and overall improvements in surgical treatment options and general supportive care. Furthermore, recent data shows that the survival of those with pulmonary arterial hypertension is improving. While there has been tremendous progress, much work remains to be done in improving the care of those with secondary forms of pulmonary hypertension, who constitute the majority of patients with this disorder, and in the optimal treatment approach in those with pulmonary arterial hypertension. This article will review general and targeted medical treatment, along with surgical interventions, of those with pulmonary hypertension.

Pulmonary hypertension related to left-sided cardiac pathology

Pulmonary hypertension (PH) is the end result of a variety of diverse pathologic processes. The chronic elevation in pulmonary artery pressure often leads to right ventricular pressure overload and subsequent right ventricular failure. In patients with left-sided cardiac disease, PH is quite common and associated with increased morbidity and mortality. This article will review the literature as it pertains to the epidemiology, pathogenesis, and diagnosis of PH related to aortic valve disease, mitral valve disease, left ventricular systolic and diastolic dysfunction, and pulmonary veno-occlusive disease. Moreover, therapeutic strategies, which focus on treating the underlying cardiac pathology will be discussed.

Novel computed tomographic chest metrics to detect pulmonary hypertension

Background

Early diagnosis of pulmonary hypertension (PH) can potentially improve survival and quality of life. Detecting PH using echocardiography is often insensitive in subjects with lung fibrosis or hyperinflation. Right heart catheterization (RHC) for the diagnosis of PH adds risk and expense due to its invasive nature. Pre-defined measurements utilizing computed tomography (CT) of the chest may be an alternative non-invasive method of detecting PH.

Methods

This study retrospectively reviewed 101 acutely hospitalized inpatients with heterogeneous diagnoses, who consecutively underwent CT chest and RHC during the same admission. Two separate teams, each consisting of a radiologist and pulmonologist, blinded to clinical and RHC data, individually reviewed the chest CT's.

Results

Multiple regression analyses controlling for age, sex, ascending aortic diameter, body surface area, thoracic diameter and pulmonary wedge pressure showed that a main pulmonary artery (PA) diameter ≥29 mm (odds ratio (OR) = 4.8), right descending PA diameter ≥19 mm (OR = 7.0), true right descending PA diameter ≥ 16 mm (OR = 4.1), true left descending PA diameter ≥ 21 mm (OR = 15.5), right ventricular (RV) free wall ≥ 6 mm (OR = 30.5), RV wall/left ventricular (LV) wall ratio ≥0.32 (OR = 8.8), RV/LV lumen ratio ≥1.28 (OR = 28.8), main PA/ascending aorta ratio ≥0.84 (OR = 6.0) and main PA/descending aorta ratio ≥ 1.29 (OR = 5.7) were significant predictors of PH in this population of hospitalized patients.

Conclusion

This combination of easily measured CT-based metrics may, upon confirmatory studies, aid in the non-invasive detection of PH and hence in the determination of RHC candidacy in acutely hospitalized patients.

Contribution of oxidative stress to pulmonary arterial hypertension

Recent data implicate oxidative stress as a mediator of pulmonary hypertension (PH) and of the associated pathological changes to the pulmonary vasculature and right ventricle (RV). Increases in reactive oxygen species (ROS), altered redox state, and elevated oxidant stress have been demonstrated in the lungs and RV of several animal models of PH, including chronic hypoxia, monocrotaline toxicity, caveolin-1 knock-out mouse, and the transgenic Ren2 rat which overexpresses the mouse renin gene. Generation of ROS in these models is derived mostly from the activities of the nicotinamide adenine dinucleotide phosphate oxidases, xanthine oxidase, and uncoupled endothelial nitric oxide synthase. As disease progresses circulating monocytes and bone marrow-derived monocytic progenitor cells are attracted to and accumulate in the pulmonary vasculature. Once established, these inflammatory cells generate ROS and secrete mitogenic and fibrogenic cytokines that induce cell proliferation and fibrosis in the vascular wall resulting in progressive vascular remodeling. Deficiencies in antioxidant enzymes also contribute to pulmonary hypertensive states. Current therapies were developed to improve endothelial function, reduce pulmonary artery pressure, and slow the progression of vascular remodeling in the pulmonary vasculature by targeting deficiencies in either NO (PDE-type 5 inhibition) or PGI(2) (prostacyclin analogs), or excessive synthesis of ET-1 (ET receptor blockers) with the intent to improve patient clinical status and survival. New therapies may slow disease progression to some extent, but long term management has not been achieved and mortality is still high. Although little is known concerning the effects of current pulmonary arterial hypertension treatments on RV structure and function, interest in this area is increasing. Development of therapeutic strategies that simultaneously target pathology in the pulmonary vasculature and RV may be beneficial in reducing mortality associated with RV failure.

Advances in diagnosis and treatment of pulmonary arterial hypertension in neonates and children with congenital heart disease

BACKGROUND

This article aims to review recent advances in the diagnosis and treatment of pulmonary arterial hypertension in neonates and children with congenital heart disease.

DATA SOURCES

Articles on pulmonary arterial hypertension in congenital heart disease were retrieved from PubMed and MEDLINE published after 1958.

RESULTS

A diagnosis of primary (or idiopathic) pulmonary arterial hypertension is made when no known risk factor is identified. Pulmonary arterial hypertension associated with congenital heart disease constitutes a heterogenous group of conditions and has been characterized by congenital systemic-to-pulmonary shunts. Despite the similarities in histologic appearance of pulmonary vascular disease, there are differences between pulmonary arterial hypertension secondary to congenital systemic-to-pulmonary shunts and those with other conditions with respect to pathophysiology, therapeutic strategies, and prognosis. Revision and subclassification within the category of secondary pulmonary arterial hypertension based on pathophysiology were conducted to improve specific treatments. The timing of surgical repair is crucial to prevent and minimize risk of postoperative pulmonary arterial hypertension. Drug therapies including prostacyclin, endothelin-receptor antagonist, phosphodiesterase inhibitor, and nitric oxide have been evolved with promising results in neonates and children.

CONCLUSIONS

Among the different forms of congenital heart diseases, an early correction generally prevents subsequent development of pulmonary arterial hypertension. Emerging therapies for treatment of patients with idiopathic pulmonary arterial hypertension also improve quality of life and survival in neonates and children with congenital heart disease associated with pulmonary arterial hypertension. Heart and lung transplantation or lung transplantation in combination with repair of the underlying cardiac defect is a therapeutic option in a minority of patients. Partial repair options are also beneficial in some selected cases. Randomized controlled trials are needed to evaluate the safety and efficacy of these therapies including survival and long-term outcome.

Pulmonary arterial hypertension in children: Diagnostic work-up and challenges

The diagnostic evaluation of a pediatric patient with suspected pulmonary arterial hypertension (PAH) is extensive but essential, given the rapid progression of the disease if left undiagnosed and untreated. The major goals of performing a complete diagnostic work-up are to confirm the diagnosis of PAH, assess disease severity, rule out associated diseases, and begin to formulate an individualized treatment plan for the pediatric patient with pulmonary hypertension. This article will provide a comprehensive review of the diagnostic work-up of the child with suspected PAH as well as a review of some of the challenges faced when assessing a child for PAH.