Primary pulmonary hypertension

Acute on Chronic Thromboembolic Pulmonary Hypertension: Case Series and Review of Management

Chronic thromboembolic pulmonary hypertension (CTEPH) is a distinct form of precapillary pulmonary hypertension classified as group 4 by the World Symposium on Pulmonary Hypertension (WSPH) and should be excluded during an episode of acute pulmonary embolism (PE). Patients presenting to emergency departments with sudden onset of signs and symptoms of acute PE may already have a pre-existing CTEPH condition decompensated by the new PE episode. Identifying an underlying and undiagnosed CTEPH during acute PE, while challenging, is an important consideration as it will alter the patients’ acute and long-term management. Differential diagnosis and evaluation require an interdisciplinary expert team. Analysis of the clinical condition, the CT angiogram, and the hemodynamic situation are important considerations; patients with CTEPH usually have significantly higher sPAP at the time of index PE, which is unusual and unattainable in the context of acute PE and a naïve right ventricle. The imaging may reveal signs of chronic disease such as right ventricle hypertrophy bronchial collaterals and atypical morphology of the thrombus. There is no standard for the management of acute on chronic CTEPH. Herein, we provide a diagnostic and management algorithm informed by several case descriptions and a review of the literature.

Pulmonary hypertension: From an orphan disease to a global epidemic

[No abstract. Showing first paragraph of article]Pulmonary hypertension is a progressive disease characterized by an elevation of pulmonary artery pressure and pulmonary vascular resistance, leading to right ventricular failure and death. It remains a challenging chronic progressive disease, but the current interest and advent of medical therapy in the last 20 years has significantly changed the perception of medical community in this disease. Pulmonary hypertension is not a specific disease; the majority of cases present with other diseases and various pathological processes that affect the pulmonary vasculature, and consequently increase pulmonary pressure and vascular resistance.

Pulmonary arterial hypertension outcomes upon endothelin-1 receptor antagonist switch to macitentan

OBJECTIVES

To assess whether switching patients with suboptimally controlled pulmonary arterial hypertension from bosentan or ambrisentan to macitentan would improve six-minute walk test (6MWT) distance and World Health Organization functional class.

METHODS

This was a retrospective cohort analysis of 37 patients from a single center. Patients were separated into three heterogeneous treatment groups and followed for 18 months: switch group (n = 14): patients switched to macitentan from bosentan/ambrisentan; added group (n = 11): patients who began macitentan as de novo therapy (n = 5) or who added macitentan to an existing sildenafil regimen (n = 6); and control group (n = 12): patients for whom sildenafil and/or bosentan/ambrisentan therapy was unchanged.

RESULTS

Mortality was observed in two patients (one each, switch and added groups). Patients in the control group had one hospital admission and 100% survival. There was significant improvement in functional class for the switch and added groups. Statistically significant improvement was observed in 6MWT distance in the added group alone. Overall, 92% of patients continued macitentan throughout the study.

CONCLUSION

Macitentan was well tolerated. For bosentan/ambrisentan-treated patients with suboptimally controlled pulmonary arterial hypertension, switching to macitentan may facilitate an improvement in functional class.

Chronic thromboembolic pulmonary hypertension from the perspective of patients with pulmonary embolism

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but feared long-term complication of acute pulmonary embolism (PE), although CTEPH may occur in patients with no history of symptomatic venous thromboembolism. It represents the most severe presentation of the so-called 'post-PE syndrome', a phenomenon of permanent functional limitations after PE caused by deconditioning after PE or ventilatory or circulatory impairment as a result of unresolved pulmonary artery thrombi. Because the post-PE syndrome may occur in up to 50% of PE survivors, and CTEPH tends to have an insidious and non-specific clinical presentation, CTEPH is often not diagnosed or diagnosed after a very long delay. Once the diagnosis is confirmed, the treatment of choice is pulmonary endarterectomy which effectively lowers the pulmonary vascular resistance and normalizes resting pulmonary artery pressures, leading to recovery of the right ventricle. When pulmonary endarterectomy is not technically feasible, balloon pulmonary angioplasty may be a potential acceptable alternative. Also, medical treatment may help to improve patient's symptoms and hemodynamics. Current studies are focusing on strategies for earlier CTEPH diagnosis after acute PE, as well as the most optimal treatment of inoperable patients. This review will focus on the epidemiology, risk factors, diagnosis and treatment of CTEPH from the perspective of the PE patient.

Percutaneous Coronary Intervention for a Patient with Left Main Coronary Compression Syndrome

Left main coronary compression syndrome rarely occurs in patients with severe pulmonary hypertension. A 65-year-old woman with severe pulmonary hypertension due to an atrial septal defect suffered from angina on effort. Cardiac computed-tomography and coronary angiography revealed considerable stenosis of the left main coronary artery (LMA) caused by compression between the dilated main pulmonary artery trunk and the sinus of valsalva. Stenting of the LMA under intravascular ultrasound imaging was effective for the treatment of angina. We herein report the diagnosis and management of this condition with a brief literature review.

Effects of the Arteriovenous Fistula on Pulmonary Artery Pressure and Cardiac Output in Patients with Chronic Renal Failure

Introduction

Access to the vascular system is necessary in patients with chronic renal failure planned to undergo dialysis. One of the complications of end-stage renal disease patients is pulmonary hypertension (PHT). Temporary arterio-venous access closure and successful kidney transplantation causes a significant fall in cardiac output and pulmonary artery pressure (PAP), indicating the possibility that excessive pulmonary blood flow is involved in the pathogenesis of the disease. We attempted to study the relationship of PHT with arteriovenous fistula (AVF) creation, as well as to assess the relationship between AVF flow and fistula characteristics.

Methods

Fifty patients were included in the study. Echocardiography was used to evaluate systolic PAP, cardiac output (CO), and ejection fraction (EF) before creating the AVF. After a follow-up interval of at least 6 months, a second echocardiographic assessment and a Doppler sonographic assessment of their fistula flow were carried out. Complete data were available for 34 patients.

Results

Study data were collected from 34 patients, 28 males and 6 females with a mean age of 52 yrs ranging from 15–78 yrs. The data showed a statistically significant positive correlation between fistula flow and PAP2 and PAP changes (p<0.05). Mean fistula flow was 1322 ml/min in patients without PHt and 2750 ml/min in patients with PHT. this difference (1428 ml/ min) was statistically significant (p=0.03). We found a significant negative correlation between PAP1 and EF1 and PAP2 and EF2 (p<0.05). In addition, the mean EF2 in patients without PHT was 57% in contrast to 46% in patients with PHT. Mean fistula flow in radial fistulae (mean=422 ml/min, range: 370–474 ml/min) was significantly less than brachial fistulae (mean=1463 ml, range: 270–3300 ml/min) (p=0.03). Mean systolic PAP2 of 14.8 mmHg in transplanted patients was 5.9 mmHg less than those who were not transplanted (20.7 mmHg). Diabetes was the most common cause of renal failure and diabetics had a significant reduction in their EF (15.5%) compared with non-diabetic patients (1% reduction) (p=0.016).

Conclusion

Fistula flow, PAP and EF of all patients should be checked at least 6 months after fistula creation. Patients with higher fistula flow rates and patients with diabetes mellitus need to be more closely observed. In addition, elderly patients with significant cardiac and other comorbidities may be more prone to develop symptoms after AVF creation

Safety and effectiveness of tadalafil in pediatric patients with pulmonary arterial hypertension: a sub-group analysis based on Japan post-marketing surveillance

OBJECTIVE

To evaluate the long-term safety and effectiveness of tadalafil in pediatric patients with pulmonary arterial hypertension (PAH) in real-world clinical practice.

METHODS

This is an observational surveillance of PAH patients receiving tadalafil in the contracted sites. A sub-group analysis was performed of 391 pediatric PAH patients (<18 years) who were included from 1,704 total patients in this surveillance. Safety was assessed from the frequency of adverse drug reactions (ADRs), discontinuations due to adverse events (AEs), and serious adverse drug reactions (SADRs). Effectiveness measurements included change in World Health Organization (WHO) functional classification of PAH, cardiac catheterization (pulmonary arterial pressure: PAP), and echocardiography (tricuspid regurgitation pressure gradient: TRPG). Survival rate was also measured.

RESULTS

The mean patient age was 5.7 ± 5.34 years. Associated PAH (APAH) and idiopathic PAH (IPAH) accounted for 76.0% and 17.6%, respectively, of the PAH patients. Patients were followed for up to 2 years. Among 391 patients analyzed for safety, the overall incidence rate of ADRs was 16.6%. The common ADRs (≥ 1%) were headache (2.8%), hepatic function abnormal, platelet count decreased (1.3% each), and epistaxis, (1.0%). Eleven patients (2.8%) reported 16 SADRs. Three patients died secondary to SADRs. For the effectiveness analysis, the incidence of WHO functional class improvement at 3 months, 1 year, and 2 years after the initiation of tadalafil and last observation in pediatric patients were 16.5%, 19.7%, and 16.3%, respectively. Both PAP and TRPG showed a statistically significant reduction at last observation.

CONCLUSION

This manuscript reveals the use of tadalafil in the real-world pediatric population with an acceptable safety profile in Japan.

Interstitial lung disease increases mortality in systemic sclerosis patients with pulmonary arterial hypertension without affecting hemodynamics and exercise capacity

Published data suggest that coexisting interstitial lung disease (ILD) has an impact on mortality in patients with systemic sclerosis (SSc) and pulmonary arterial hypertension (PAH), but there is scarce knowledge if this is reflected by hemodynamics, exercise capacity, autoantibody profile, or pulmonary function. In this partially retrospective study, 27 SSc-PAH patients were compared to 24 SSc-PAH patients with coexisting ILD respecting to survival, pulmonary function, hemodynamics, exercise capacity, and laboratory parameters. Survival was significantly worse in SSc-PAH-ILD patients than in SSc patients with isolated PAH (1, 5, and 10-year survival rates 86, 54, and 54% versus 96, 92, and 82%, p = 0.013). Compared to isolated SSc-PAH patients, patients with SSc-PAH-ILD revealed lower forced expiratory volume after 1 s (FEV1) values at the time of PAH diagnosis as well as 1 and 2 years later (p = 0.002) without significant decrease in the PAH course in both groups. At PAH diagnosis, diffusion capacity for carbon monoxide (DLCO) values were lower in the ILD-PAH group. Coexisting ILD was not associated with lower exercise capacity, different FEV1/forced vital capacity (FVC) ratio, higher WHO functional class, or reduced hemodynamics. Higher levels of antibodies against angiotensin and endothelin receptors predict mortality in all SSc-PAH patients but could not differentiate between PAH patients with and without ILD. Our study confirmed an impact of ILD on mortality in SSc-PAH patients. Pulmonary function parameters can be used to distinguish PAH from PAH-ILD. The higher mortality rate cannot be explained by differences in hemodynamics, exercise capacity, or autoantibody levels. Mechanisms of mortality remain to be studied.

Cardiac Dual-source Computed Tomography for the Detection of Left Main Compression Syndrome in Patients with Pulmonary Hyper-tension

INTRODUCTION

Left Main Compression Syndrome (LMCS) represents an entity described as the extrinsic compression of the left main coronary artery (LMCA) by a dilated pulmonary artery (PA) trunk. We examined the presence of LMCS in patients with pulmonary hypertension (PH) using dual-source computed tomography (DSCT), as a non-invasive diagnostic tool.

METHODS

The following parameters were measured: PA trunk diameter (PAD), the distance between PAD and LMCA (LMPA) and the distance between PA and aorta (AoPA). These measurements were related with demographic, echocardiographic, hemodynamic and clinical parameters. Angiography was performed in two patients with LMCS suspected by cardiac computed tomographic angiography. Patients without PH but with angina were examined as controls, using DSCT cardiac angiography to assess the same measurements and to detect the prevalence of coronary artery disease.

RESULTS

PA diameter value over 40.00 mm has been associated with PH and LMCS. Furthermore, LMCS did not occur at a distance smaller than 0.50 mm between the PA and the LMCA, and did not correlate with the distance between the PA and the aorta or with cardiac index and NT-proBNP.

CONCLUSION

DSCT may represent the initial testing modality in PH patients with dilated PA trunk to exclude LMCS. A periodical rule-out of this rare entity, as assessed by DSCT, in patients with a severely dilated PA seems to be mandatory for PH patients contributing to survival improvement.

Regional contribution to ventricular stroke volume is affected on the left side, but not on the right in patients with pulmonary hypertension

To develop more sensitive measures of impaired cardiac function in patients with pulmonary hypertension (PH), since detection of impaired right ventricular (RV) function is important in these patients. With the hypothesis that a change in septal function in patients with PH is associated with altered longitudinal and lateral function of both ventricles, as a compensatory mechanism, we quantified the contributions of these parameters to stroke volume (SV) in both ventricles using cardiac magnetic resonance (CMR). Seventeen patients (10 females) evaluated for PH underwent right heart catheterization (RHC) and CMR. CMR from 33 healthy adults (13 females) were used as controls. Left ventricular (LV) atrioventricular plane displacement (AVPD) and corresponding longitudinal contribution to LVSV was lower in patients (10.8 ± 3.2 mm and 51 ± 12 %) compared to controls (16.6 ± 1.9 mm and 59 ± 9 %, p < 0.0001 and p < 0.01, respectively). This decrease did not differ in patient with ejection fraction (EF) >50 % and <50 % (p = 0.5) and was compensated for by increased LV lateral contribution to LVSV in patients (49 ± 13 % vs. 37 ± 7 %, p = 0.001). Septal motion contributed less to LVSV in patients (5 ± 8 %) compared to controls (8 ± 4 %, p = 0.05). RV AVPD was lower in patients (12.0 ± 3.6 mm vs. 21.8 ± 2.2 mm, p < 0.0001) but longitudinal and lateral contribution to RVSV did not differ between patients (78 ± 17 % and 29 ± 16 %) and controls (79 ± 9 % and 31 ± 6 % p = 0.7 for both) explained by increased RV cross sectional area in patients. LV function is affected in patients with PH despite preserved global LV function. The decreased longitudinal contribution and increased lateral contribution to LVSV was not seen in the RV, contrary to previous findings in patients with volume loaded RVs.

Determinants of an elevated pulmonary arterial pressure in patients with pulmonary arterial hypertension

Given the difficulty of diagnosing early-stage pulmonary arterial hypertension (PAH) due to the lack of signs and symptoms, and the risk of an open lung biopsy, the precise pathological features of presymptomatic stage lung tissue remain unknown. It has been suggested that the maximum elevation of the mean pulmonary arterial pressure (P_pa) is achieved during the early symptomatic stage, indicating that the elevation of the mean P_pa is primarily driven by the pulmonary vascular tone and/or some degree of pulmonary vascular remodeling completed during this stage. Recently, the examination of a rat model of severe PAH suggested that the severe PAH may be primarily determined by the presence of intimal lesions and/or the vascular tone in the early stage. Human data seem to indicate that intimal lesions are essential for the severely increased pulmonary arterial blood pressure in the late stage of the disease.

However, many questions remain. For instance, how does the pulmonary hemodynamics change during the course of the disease, and what drives the development of severe PAH? Although it is generally acknowledged that both pulmonary vascular remodeling and the vascular tone are important determinants of an elevated pulmonary arterial pressure, which is the root cause of the time-dependent progression of the disease? Here we review the recent histopathological concepts of PAH with respect to the progression of the lung vascular disease.

[Management of borderline pulmonary arterial hypertension associated with connective tissue diseases]

The prognosis of connective tissue disease (CTD)-associated pulmonary arterial hypertension (PAH) is so poor that early therapeutic intervention is advisable. Borderline PAH (21-24 mmHg mean pulmonary arterial pressure) is a concept created to distinguish cases that would become definite PAH. It is controversial whether borderline PAH cases with no symptoms should be treated, but therapeutic intervention in the case of borderline PAH is justified when systemic sclerosis (SSc) is in the background, because SSc-associated PAH shows an especially poor prognosis compared to PAH associated with other CTDs, while 42-55% of SSc-associated borderline PAH cases become definite PAH within several years. However, cautious attention should be paid when pulmonary vasodilators are administered to SSc-associated PAH cases, because complications caused by SSc such as lung lesions, left heart diseases and pulmonary venous lesions can be obstacles to the success of the therapy. There is very little evidence of the efficacy of therapeutic intervention in borderline PAH. Clinical trials should be planned.

Could albumin level explain the higher mortality in hemodialysis patients with pulmonary hypertension?

Background

The pathogenesis of pulmonary hypertension (PH) in hemodialysis is still unclear. The aim of this study was to identify the risk factors associated with the presence of PH in chronic hemodialysis patients and to verify whether these factors might explain the highest mortality among them.

Methods

We conducted a retrospective study of hemodialysis patients who started treatment from August 2001 to October 2007 and were followed up until April 2011 in a Brazilian referral medical school. According to the results of echocardiography examination, patients were allocated in two groups: those with PH and those without PH. Clinical parameters, site and type of vascular access, bioimpedance, and laboratorial findings were compared between the groups and a logistic regression model was elaborated. Actuarial survival curves were constructed and hazard risk to death was evaluated by Cox regression analysis.

Results

PH > 35 mmHg was found in 23 (30.6%) of the 75 patients studied. The groups differed in extracellular water, ventricular thickness, left atrium diameter, and ventricular filling. In a univariate analysis, extracellular water was associated with PH (relative risk = 1.194; 95% CI of 1.006 – 1.416; p = 0.042); nevertheless, in a multiple model, only left atrium enlargement was independently associated with PH (relative risk =1.172; 95% CI of 1.010 – 1.359; p = 0.036). PH (hazard risk = 3.008; 95% CI of 1.285 – 7.043; p = 0.011) and age (hazard risk of 1.034 per year of age; 95% CI of 1.000 – 7.068; p = 0.047) were significantly associated with mortality in a multiple Cox regression analysis. However, when albumin was taken in account the only statistically significant association was between albumin level and mortality (hazard risk = 0.342 per g/dL; 95% CI of 0.119 – 0.984; p = 0.047) while the presence of PH lost its statistical significance (p = 0.184). Mortality was higher in patients with PH (47.8% vs 25%) who also had a statistically worse survival after the sixth year of follow up.

Conclusions

PH in hemodialysis patients is associated with parameters of volume overload that sheds light on its pathophysiology. Mortality is higher in hemodialysis patients with PH and the low albumin level can explain this association.

Pulmonary hypertension: screening and evaluation in scleroderma

PURPOSE OF REVIEW

The review provides an update of the epidemiology, pathogenesis, risk factors, screening and treatment of pulmonary arterial hypertension in systemic sclerosis.

RECENT FINDINGS

Several recent studies have investigated the utility of several noninvasive screening methods and the propagation of new treatments promise the clinician better outcomes than the current median survival time of 1 year for patients with scleroderma-related pulmonary arterial hypertension.

SUMMARY

Pulmonary hypertension is a frequent cause of morbidity and mortality in patients with systemic sclerosis. This review discusses the recent changes in the classification of pulmonary hypertension, especially the significance for the rheumatologist. A high clinical suspicion should be maintained, even in early scleroderma. Despite progress in echocardiography and biomarkers, right heart catheterization remains the only test that can diagnose pulmonary hypertension and differentiate pulmonary veno-occlusive disease from pulmonary arterial hypertension. The differentiation of these causes of pulmonary hypertension in the scleroderma patient is essential because the initiation of pulmonary vasodilators in veno-occlusive disease often leads to increased mortality. The role of screening with serum biomarkers and noninvasive testing remains controversial, and in this review we discuss the controversies and new recommendations in detail.

Pulmonary arterial hypertension: pathobiology, diagnosis, treatment, and emerging therapies

Pulmonary hypertension is a rare disorder caused by vasoconstriction of the pulmonary arteries that leads to elevation of pulmonary vascular resistance, right ventricular failure, and ultimately death. Hypertrophy and proliferation of the pulmonary vascular endothelium leads to remodeling of this vascular system, resulting in a progressive disorder. In the past decade the molecular mechanisms and pathobiology of this disorder has become clearer. In addition, a host of new medical treatments and therapies are now available for what has been previously known to be a devastating disorder. Although much needs to be learned, this review will discuss our current knowledge, results of clinical trials, along with treatment options and emerging therapies available for the treatment of this disorder.

Pulmonary arterial hypertension: a comparison between children and adults

The characteristics of pulmonary arterial hypertension (PAH), including pathology, symptoms, diagnosis and treatment are reviewed in children and adults. The histopathology seen in adults is also observed in children, although children have more medial hypertrophy at presentation. Both populations have vascular and endothelial dysfunction. Several unique disease states are present in children, as lung growth abnormalities contribute to pulmonary hypertension. Although both children and adults present at diagnosis with elevations in pulmonary vascular resistance and pulmonary artery pressure, children have less heart failure. Dyspnoea on exertion is the most frequent symptom in children and adults with PAH, but heart failure with oedema occurs more frequently in adults. However, in idiopathic PAH, syncope is more common in children. Haemodynamic assessment remains the gold standard for diagnosis, but the definition of vasoreactivity in adults may not apply to young children. Targeted PAH therapies approved for adults are associated with clinically meaningful effects in paediatric observational studies; children now survive as long as adults with current treatment guidelines. In conclusion, there are more similarities than differences in the characteristics of PAH in children and adults, resulting in guidelines recommending similar diagnostic and therapeutic algorithms in children (based on expert opinion) and adults (evidence-based).

HIV and pulmonary arterial hypertension: a systematic review

OBJECTIVES

HIV-related pulmonary arterial hypertension (PAH) is a rare entity but is associated with significant morbidity and mortality. The literature describing the outcomes of therapy for this disease is limited to case series and cohort studies. The objective of this study was to systematically review and synthesize the literature on HIV-related PAH.

METHODS

MEDLINE, EMBASE, PapersFirst, the Cochrane collaboration and the Cochrane Register of controlled trials were searched with pre-defined search terms. Randomized controlled trials, observational cohort studies, case-control studies and case reports were considered for inclusion in the qualitative analysis.

RESULTS

A total of 180 case reports of PAH in HIV-infected patients were identified. Twenty-six were excluded and thus 154 case reports were included in the qualitative analysis. Thirteen cohort, one case series and two case-control studies were also identified and included in the review. The average baseline CD4 count at the time of diagnosis of PAH was 352 ± 304 cells/μL. The average time from diagnosis of HIV infection to diagnosis of PAH was 4.3 ± 4.0 years. Predominant chest X-ray findings included cardiomegaly (80%) and pulmonary arterial enlargement (75%). Highly active antiretroviral therapy, bosentan, and prostaglandin therapy have all been reported to be beneficial in improving haemodynamic and functional status in HIV-related PAH.

CONCLUSION

HIV-related PAH is a rare entity with clinical, laboratory, imaging and pathological manifestations similar to those of idiopathic PAH. The evidence for various treatments is limited to cohort, case series and case-control studies. Randomized controlled trials are needed to properly assess the utility of these therapies in the treatment of HIV-related PAH.

Long-term epoprostenol therapy in pulmonary artery hypertension

BACKGROUND

Sequential changes in the hemodynamic effect of chronic epoprostenol therapy raise the following questions. Does an increase in cardiac output (CO) precede lowering of the pulmonary artery pressure (PAP) over the time course of improvement? What are the characteristics of good responders to chronic epoprostenol treatment?

METHODS AND RESULTS

Hemodynamics were evaluated by catheter examination. Most patients still alive after >1 year showed an increase in CO either with no change in mean PAP or accompanied by a decrease in mean PAP during increased dosing of epoprostenol. Immediately before cessation of the increase in epoprostenol dose in good responders, the ratio of total pulmonary resistance to total systemic resistance was low, and the pulmonary artery wedge pressure minus right atrial pressure was high compared with the newest data in poor responders. One year after fixing at the best dose of epoprostenol, the mean PAP further decreased.

CONCLUSIONS

In good responders, pulmonary selectivity to epoprostenol is high, and the blood returning to the left-sided heart through the pulmonary circulation increases. Hemodynamics further improve, even after fixing at the best dose of epoprostenol. The present data did not show that an increase in CO precedes lowering of the PAP over the course of improvement.

Arterio-venous access in end-stage renal disease patients and pulmonary hypertension

Background: The syndrome of pulmonary hypertension (PHT) in end-stage renal disease (ESRD) has been described in patients on chronic hemodialysis (HD) therapy via arterial-venous (A-V) access. However, the exact timing for the development of the PHT is unknown. This study was designed to evaluate changes in pulmonary artery pressure (PAP) following creation of the vascular access.

Patients and Methods: PAP and cardiac-output (CO) values were recorded in 12 pre-dialysis patients without PHT a few months after the access formation, before treatment with HD was started, and the prevalence of PHT was calculated. Clinical data was compared between patients with and without PHT.

Results: The systolic PAP values were increased in “ve of the 12 pre-dialysis patients (42%) by 21±9 mm Hg to more than 35 mm Hg. Patients with and without PHT differed only in that CO was signi“cantly higher among the former.

Conclusions: The development of PHT following access formation represents a failure of the pulmonary circulation to accommodate the access-mediated elevated CO. Pre-dialysis patients scheduled for access formation should be screened for the presence of sub-clinical PHT. “Positive” patients should proceed to peritoneal dialysis or advance to kidney transplantation; rather than getting access and HD therapy.

Hyperproliferative apoptosis-resistant endothelial cells in idiopathic pulmonary arterial hypertension

Idiopathic pulmonary arterial hypertension (IPAH) is characterized by plexiform vascular lesions, which are hypothesized to arise from deregulated growth of pulmonary artery endothelial cells (PAEC). Here, functional and molecular differences among PAEC derived from IPAH and control human lungs were evaluated. Compared with control cells, IPAH PAEC had greater cell numbers in response to growth factors in culture due to increased proliferation as determined by bromodeoxyuridine incorporation and Ki67 nuclear antigen expression and decreased apoptosis as determined by caspase-3 activation and TdT-mediated dUTP nick end labeling assay. IPAH cells had greater migration than control cells but less organized tube formation in in vitro angiogenesis assay. Persistent activation of signal transducer and activator of transcription 3 (STAT3), a regulator of cell survival and angiogenesis, and increased expression of its downstream prosurvival target, Mcl-1, were identified in IPAH PAEC. A Janus kinase (JAK) selective inhibitor reduced STAT3 activation and blocked proliferation of IPAH cells. Phosphorylated STAT3 was detected in endothelial cells of IPAH lesions in vivo, suggesting that STAT3 activation plays a role in the proliferative pulmonary vascular lesions in IPAH lungs.

Pulmonary hypertension in chronic dialysis patients with arteriovenous fistula: pathogenesis and therapeutic prospective

PURPOSE OF REVIEW

End-stage renal disease patients receiving chronic haemodialysis via arteriovenous access often develop various cardiovascular complications, including vascular calcification, cardiac-vascular calcification and atherosclerotic coronary disease. This review describes recently published studies that demonstrate a high incidence of pulmonary hypertension among patients with end-stage renal disease receiving long-term haemodialysis via a surgical arteriovenous fistula. Both end-stage renal disease and long-term haemodialysis via arteriovenous fistula may be involved in the pathogenesis of pulmonary hypertension by affecting pulmonary vascular resistance and cardiac output.

RECENT FINDINGS

Morbidity and mortality from cardiovascular disease are greatly increased in patients on maintenance haemodialysis therapy. Using Doppler echocardiography, we found a significant increase in cardiac output in 40% of chronic haemodialysis patients, probably related to the large arteriovenous access or altered vascular resistance as a result of the local vascular tone and function expressed by the imbalance between vasodilators such as nitric oxide, and vasoconstrictors such as endothelin-1.

SUMMARY

We propose different potential mechanisms as explanations for the development of pulmonary hypertension. Hormonal and metabolic derangement associated with end-stage renal disease might lead to pulmonary arterial vasoconstriction and an increase in pulmonary vascular resistance. Pulmonary arterial pressure may be further increased by high cardiac output resulting from the arteriole-venous access itself, worsened by commonly occurring anaemia and fluid overload.

Doppler echocardiograph evaluation of pulmonary hypertension in patients undergoing hemodialysis

Pulmonary hypertension (PH) has been reported in hemodialysis (HD) patients, but data regarding its incidence and mechanisms are scarce. The aims of this study was to evaluate the prevalence of unexplained PH in long-term HD patients, and to examine some possible etiologic factors for its occurrence. The prevalence of PH was estimated by Doppler echocardiography in a cohort of 86 stable patients on HD via arteriovenous access for more than 12 months. All the patients underwent full clinical evaluation, chest radiography, and a standard 12-lead echocardiograph. Laboratory investigation included a mean of 12 months (serum calcium, phosphorus, parathormone (PTH), alkaline phosphatase, lipids, and hemoglobin). Pulmonary hypertension was defined as pulmonary artery systolic pressure >35 mmHg as determined by Doppler echocardiography using the modified Bernoulli equation. Pulmonary hypertension was detected in 23 patients (26.74%). Of those with PH, left ventricular hypertrophy was seen in 13 patients (56.52%), and valvular calcifications in 6 patients (26.08%). There were no significant differences between both groups with regard to age, sex, duration of dialysis, shunt location, and all the biological parameters of the study. The presence of PH was not related to the level of PTH, or the severity of other metabolic abnormalities. This study demonstrates a high prevalence of PH among patients with ESRD receiving long-term HD via surgical arteriovenous access. The role of the vascular access, anemia, or secondary hyperparathyroidism as the etiology of PH in HD patients did not hold in this study.

Use of noninvasive tools in primary pulmonary hypertension to assess the correlation of right ventricular function with functional capacity and to predict outcome

Most patients with Primary Pulmonary Hypertension (PPH) have severe exertional limitation which ultimately leads to right heart failure and death. The purpose of the study was to assess the correlation between right ventricular (RV) systolic and diastolic noninvasive variables and exercise tolerance, as well as the predictors of adverse outcome in treated patients.

METHODS

We prospectively studied 29 patients, 17 with PPH and 12 with PPH due to collagen disease. RV parameters were assessed by echocardiography and Radionuclide ventriculography. Pulmonary function and clinical profile were assessed by 6 min walk test and NYHA class. The patients were followed-up during 2 years for cardiac death and cardiac deterioration.

RESULTS

Mean age was 51 +/- 15 years, 22 (78%) women. NYHA class1 in 2 pts, class 2 in 17, class 3 in 8 and class 4 in 2 pts. Pulmonary function (DLCO) was low in 25 (86%) pts, mean 22 +/- 48%. Six minutes walk distance was 358 +/- 132 m, RVEF was 34 +/- 11% (range 16-51%). Among RV variables, RVEF, RA area and TR were independently correlated to 6 min walk. Within follow up of 2 years, there were 10 patients with adverse outcome (4 deaths and 6 deteriorated to NYHA class 3 and 4). Among all clinical and noninvasive variables, RVEF only was correlated to adverse outcome.

CONCLUSION

The noninvasive tests of RVEF, RA size and TR were closely correlated to exercise tolerance. However, among the various clinical, functional and RV variables, RVEF was the only variable correlated with adverse outcome in pts with PPH.

Increased plasma monocyte chemoattractant protein-1 level in idiopathic pulmonary arterial hypertension

OBJECTIVE

Monocyte chemoattractant protein-1 (MCP-1), a pro-inflammatory chemokine, has potent chemoattractant activity for monocytes/macrophages. We sought to investigate the clinical significance of MCP-1 in idiopathic pulmonary arterial hypertension (IPAH).

METHODS

This study included 28 patients with IPAH, seven patients with pulmonary arterial hypertension (PAH) related to collagen vascular disease, and 13 healthy subjects. Plasma MCP-1 levels were measured together with serum IL-6 and tumour necrosis factor-alpha (TNF-alpha) levels.

RESULTS

Circulating levels of MCP-1, IL-6 and TNF-alpha were significantly higher in patients with IPAH than in healthy controls, although they were lower than in patients with PAH related to collagen vascular disease. Plasma MCP-1 did not significantly correlate with any haemodynamic variables. However, plasma MCP-1 levels correlated negatively with the disease duration (time from symptom onset).

CONCLUSIONS

Plasma MCP-1 levels were elevated in patients with IPAH, and this elevation was particularly marked in the early stage of disease. Taking into account the chemoattractant activity of MCP-1, these results imply a contribution of MCP-1 to the development of pulmonary hypertension.

Increased [18F]fluorodeoxyglucose accumulation in right ventricular free wall in patients with pulmonary hypertension and the effect of epoprostenol

OBJECTIVES

We examined whether right ventricular (RV) [(18)F]fluorodeoxyglucose (FDG) accumulation is increased in patients with pulmonary hypertension using gated positron emission tomography (PET) and whether RV FDG accumulation changes after therapy with epoprostenol.

BACKGROUND

Myocardial glucose utilization is increased in animal models with ventricular pressure overload.

METHODS

We performed gated FDG-PET in 24 patients with pulmonary hypertension. The RV standardized uptake value (SUV) of FDG was corrected for the partial volume effect based on the wall thickness measured by electron-beam computed tomography or magnetic resonance imaging.

RESULTS

The corrected RV SUV of FDG was significantly correlated with the pulmonary vascular resistance, mean pulmonary artery pressure, right atrial pressure, RV wall stress, and plasma brain natriuretic peptide levels, but not with the RV wall thickness and mass. After pulmonary vasodilator therapy with epoprostenol for three months, the corrected RV SUV of FDG significantly decreased in the responders, but not in the non-responders, and the percentage change of the corrected RV SUV of FDG was significantly correlated with the percentage change of the pulmonary vascular resistance (r = 0.78; p < 0.01) and RV systolic wall stress (r = 0.76; p < 0.05).

CONCLUSIONS

The RV FDG accumulation corrected for the partial volume effect was significantly increased in accordance with the severity of the RV pressure overload (i.e., the RV peak-systolic wall stress) in patients with pulmonary hypertension. Furthermore, the corrected RV FDG accumulation was decreased after the treatment with epoprostenol in accordance with the degree of reduction in the pulmonary vascular resistance and RV peak-systolic wall stress.

Adrenomedullin in the treatment of pulmonary hypertension

Adrenomedullin (AM) is a potent, long-lasting pulmonary vasodilator peptide. Plasma AM level is elevated in patients with primary pulmonary hypertension (PPH), and circulating AM is partially metabolized in the lungs. These findings suggest that AM plays an important role in the regulation of pulmonary vascular tone and vascular remodeling. We have demonstrated the effects of three types of AM delivery systems: intravenous administration, inhalation, and cell-based gene transfer. Despite endogenous production of AM, intravenously administered AM at a pharmacologic level decreased pulmonary vascular resistance in patients with PPH. Inhalation of AM improved hemodynamics with pulmonary selectivity and exercise capacity in patients with PPH. Cell-based AM gene transfer ameliorated pulmonary hypertension rats. These results suggest that additional administration of AM may be effective in patients with pulmonary hypertension. AM may be a promising endogenous peptide for the treatment of pulmonary hypertension.

A new era in the management of pulmonary arterial hypertension related to scleroderma: endothelin receptor antagonism

Evidence suggests that endothelin may have a fundamental role in scleroderma pathogenesis, including pulmonary arterial hypertension (PAH)--a leading cause of death in patients with scleroderma. Development of a new class of drug, endothelin receptor antagonists, heralds an improved outlook for patients with scleroderma and related diseases. Heightened vigilance towards early detection of PAH in scleroderma and a multidisciplinary approach to diagnosis and treatment may improve clinical outcomes for these patients.

Likelihood of left main coronary artery compression based on pulmonary trunk diameter in patients with pulmonary hypertension

PURPOSE

In patients with pulmonary hypertension, extrinsic compression of the left main coronary artery by a dilated pulmonary trunk may cause angina, left ventricular ischemia, and sudden death. We assessed coronary artery compression in relation to pulmonary trunk diameter and other demographic, echocardiographic, hemodynamic, and scintigraphic variables.

METHODS

Thirty-six patients (aged 15 to 86 years) with pulmonary hypertension, either idiopathic or associated with congenital heart disease, were enrolled. Left main coronary artery compression was defined angiographically as > or =50% obstruction associated with downward displacement of the vessel. Pulmonary trunk and aortic diameters were measured by transthoracic echocardiography.

RESULTS

Twenty-six patients had angina, of whom 7 had left coronary artery compression. Compression was related to pulmonary trunk diameter (P = 0.002) and to the ratio of pulmonary trunk diameter to aortic diameter (P = 0.02). Compression was not seen at pulmonary artery diameters <40 mm; among 19 patients with values > or =40 mm, the rate was 37%. Similarly, compression did not occur at pulmonary trunk to aortic diameter ratios <1.21; among 27 patients with ratios > or =1.21, the rate was 26%.

CONCLUSION

In pulmonary hypertension, noninvasive measurement of pulmonary trunk diameter may be helpful in determining the likelihood of left coronary artery compression and in selecting patients for diagnostic coronary angiography.

Effects of adrenomedullin inhalation on hemodynamics and exercise capacity in patients with idiopathic pulmonary arterial hypertension

BACKGROUND

Adrenomedullin (AM) is a potent pulmonary vasodilator peptide. However, whether intratracheal delivery of aerosolized AM has beneficial effects in patients with idiopathic pulmonary arterial hypertension remains unknown. Accordingly, we investigated the effects of AM inhalation on pulmonary hemodynamics and exercise capacity in patients with idiopathic pulmonary arterial hypertension.

METHODS AND RESULTS

Acute hemodynamic responses to inhalation of aerosolized AM (10 microg/kg body wt) were examined in 11 patients with idiopathic pulmonary arterial hypertension during cardiac catheterization. Cardiopulmonary exercise testing was performed immediately after inhalation of aerosolized AM or placebo. The work rate was increased by 15 W/min until the symptom-limited maximum, with breath-by-breath gas analysis. Inhalation of AM produced a 13% decrease in mean pulmonary arterial pressure (54+/-3 to 47+/-3 mm Hg, P<0.05) and a 22% decrease in pulmonary vascular resistance (12.6+/-1.5 to 9.8+/-1.3 Wood units, P<0.05). However, neither systemic arterial pressure nor heart rate was altered. Inhalation of AM significantly increased peak oxygen consumption during exercise (peak o(2), 14.6+/-0.6 to 15.7+/-0.6 mL. kg(-1). min(-1), P<0.05) and the ratio of change in oxygen uptake to that in work rate (Deltao(2)/DeltaW ratio, 6.3+/-0.4 to 7.0+/-0.5 mL. min(-1). W(-1), P<0.05). These parameters remained unchanged during placebo inhalation.

CONCLUSIONS

Inhalation of AM may have beneficial effects on pulmonary hemodynamics and exercise capacity in patients with idiopathic pulmonary arterial hypertension.

Treatment of pulmonary arterial hypertension: a preliminary decision analysis

STUDY OBJECTIVE

New therapies for pulmonary arterial hypertension (PAH) improve functional status, quality of life (QOL), and survival. Clinicians must chose between very different therapies without the availability of comparison studies. We constructed a "virtual" clinical trial to help inform these treatment choices.

DESIGN

We compare key outcomes related to survival, costs, and QOL using a Markov-type decision model to estimate the expected outcomes and costs for PAH patients treated for 1 year with bosentan and treprostinil compared to patients treated with epoprostenol, as well as patients treated with bosentan compared to those treated with treprostinil. The allowed transitions in the model were between World Health Organization functional class I to IV and death. Transition probabilities were based on observed transitions for bosentan. Treatment effect was estimated using 6-min walk data for treprostinil and epoprostenol. Utilities were calculated from estimated EuroQol health states. Cost was estimated from average wholesale price and Medicare reimbursement data. The effects of changing values of input variables on the key outcomes were calculated.

RESULTS

Treatment with bosentan compared to treatment with either epoprostenol or treprostinil was less costly and resulted in a greater gain in quality-adjusted life years (QALYs). Conversely, treprostinil was significantly more expensive than epoprostenol, without an appreciable gain in QALYs. These findings were not substantially affected by the reasonable adjustments of transition probabilities, utility values, or tachyphylaxis to epoprostenol.

CONCLUSION

Treatment with bosentan is more cost-effective than treatment with either treprostinil or epoprostenol. In addition, a net improvement in quality-adjusted survival may be expected.

Pulmonary arterial hypertension: a new era in management

Pulmonary arterial hypertension (PAH) is a heterogeneous condition with a wide range of causes. The diagnosis is often delayed or missed. PAH is covert in its early stages, when its detection and treatment should have the most impact. Access in Australia to effective PAH therapies has lagged behind that in other affluent countries. New agents for PAH, now becoming available, improve symptoms and reduce pulmonary resistance, with some demonstrating an ability to reverse remodelling of the right ventricle. Best management of PAH is comprehensive and multidisciplinary. Centres of excellence are needed in geographically strategic areas. Aggressive efforts must be made to diagnose PAH and to facilitate access to effective therapies.

Pulmonary hypertension in patients with end-stage renal disease

BACKGROUND

The aims of this study were to evaluate the incidence of unexplained pulmonary hypertension (PH) among patients with end-stage renal disease (ESRD) and to suggest possible etiologic factors.

METHODS

The incidence of PH was prospectively estimated by Doppler echocardiography in 58 patients with ESRD receiving long-term hemodialysis via arteriovenous access, and in control groups of 5 patients receiving peritoneal dialysis (PD) and 12 predialysis patients without a known other cause to suggest the presence of PH. Clinical variables were compared between patients with and without PH receiving hemodialysis. Changes in pulmonary artery pressure (PAP) values before and after onset of hemodialysis via arteriovenous access, arteriovenous access compression, and successful kidney transplantation were recorded.

RESULTS

PH > 35 mm Hg was found in 39.7% of patients receiving hemodialysis (mean +/- SD, 44 +/- 7 mm Hg; range, 37 to 65 mm Hg), in none of the patients receiving PD, and in 1 of 12 predialysis patients. Patients with PH receiving hemodialysis had a significantly higher cardiac output (6.9 L/min vs 5.5 L/min, p = 0.017). PH developed in four of six patients with normal PAP after onset of hemodialysis therapy via arteriovenous access. One-minute arteriovenous access compression in four patients decreased the mean systolic PAP from 52 +/- 7 to 41 +/- 4 mm Hg (p = 0.024). PH normalized in four of five patients receiving hemodialysis following kidney transplantation. Kaplan-Meier survival analysis according to PAP values revealed significant survival differences (p < 0.024).

CONCLUSIONS

This study demonstrates a surprisingly high incidence of PH among patients with ESRD receiving long-term hemodialysis with surgical arteriovenous access. Both ESRD and long-term hemodialysis via arteriovenous access may be involved in the pathogenesis of PH by affecting pulmonary vascular resistance and cardiac output.

Stenting to reverse left ventricular ischemia due to left main coronary artery compression in primary pulmonary hypertension

Angina is a common symptom of severe pulmonary hypertension. Although many theories for the source of this pain have been proposed, right ventricular ischemia is the one most commonly accepted as the cause. We report on two patients with primary pulmonary hypertension who had angina with normal activity or on provocation. One patient had severe left ventricular dysfunction. Both were found to have severe ostial stenosis of the left main coronary artery as a result of compression from a dilated pulmonary artery. Both patients underwent stenting of the left main coronary artery with excellent angiographic results, and complete resolution of the signs and symptoms of angina and left ventricular ischemia. Left ventricular ischemia due to compression of the left main coronary artery may be a much more common mechanism of angina and left ventricular dysfunction in patients with pulmonary hypertension than previously acknowledged. Stenting of the coronary artery can be done safely with the resolution of these symptoms.

Survival and prognostic factors in patients with primary pulmonary hypertension

OBJECTIVES

Primary pulmonary hypertension (PPH) that affects predominantly young and productive people is a progressive fatal disease of unknown cause. The objectives of this study were to characterize mortality in patients with PPH and to investigate the factors associated with their survival.

METHODS

Thirteen patients with PPH were enrolled between 1988 and 1996 and followed-up through July 1999. Measurements at diagnosis included hemodynamic and pulmonary function variables in addition to information on demographic data and medical history.

RESULTS

1) The mean age of the patients with PPH enrolled into the study was 36.1 +/- 9.3 years with female predominance. 2) The estimated median survival was 3.4 +/- 0.6 years. 3) Decreased cardiac index was the only significant predictor of mortality (Cox proportional hazards model).

CONCLUSION

Patients with PPH have a poor survival expectancy. In this limited study with a small number of patients, mortality is largely associated with decreased cardiac index.

Aerosolized iloprost therapy could not replace long-term IV epoprostenol (prostacyclin) administration in severe pulmonary hypertension

OBJECTIVES

To switch patients with severe pulmonary hypertension and previous life-threatening catheter-related complications from long-term IV epoprostenol therapy to aerosolized iloprost therapy.

DESIGN

Open, uncontrolled trial.

SETTING

Medical ICU of a university hospital.

PATIENTS

Two patients with primary pulmonary hypertension and one patient with pulmonary hypertension after surgical closure of atrial septal defect (mean pulmonary artery pressure > or =50 mm Hg). All were classified as New York Heart Association class II under treatment with continuous IV epoprostenol for 4 years.

INTERVENTIONS

Stepwise reduction of IV epoprostenol (1 ng/kg/min steps every 3 to 10 h) during repeated inhalations of aerosolized iloprost (150 to 300 microg/d with 6 to 18 inhalations/d). Continuous pulmonary and systemic arterial monitoring were performed.

RESULTS

Aerosolized iloprost reduced pulmonary artery pressure by 49%, 49%, and 45%, respectively, and increased cardiac output by 70%, 75%, and 41% in the three patients. The effect lasted for 20 min and was similar at different doses of IV epoprostenol. Persistent treatment change to inhaled iloprost could not be achieved because all patients developed signs of right heart failure. After termination of iloprost inhalations, return to standard epoprostenol therapy led to clinical and hemodynamic restoration.

CONCLUSIONS

Although aerosolized iloprost demonstrated short-term hemodynamic effects, it could not be utilized as alternative chronic vasodilator in patients with severe pulmonary hypertension.

HIV-Related pulmonary hypertension: analytic review of 131 cases

OBJECTIVE

To report two new cases of HIV-related pulmonary hypertension and to review and analyze the existing reports on the subject.

METHOD

Two new cases of HIV-related pulmonary hypertension are described, and the cases, case series, and related articles on the subject in all languages were identified through a comprehensive MEDLINE search.

RESULTS

Among the 131 reviewed cases, 54% were male, and the age range was 2 to 56 years (mean, 33 years). The interval between the diagnosis of HIV disease and the diagnosis of pulmonary hypertension was 33 months. In 82% of cases, pulmonary hypertension was related solely to HIV infection. Presenting symptoms were progressive shortness of breath (85%), pedal edema (30%), nonproductive cough (19%), fatigue (13%), syncope or near-syncope (12%), and chest pain (7%). The mean (+/- SD) pulmonary arterial systolic BP was 67 +/- 18 mm Hg (n = 116), and diastolic BP was 40+/-11 mm Hg (n = 39). Pulmonary vascular resistance was 983+/-420 dyne. s. cm(-5) (n = 29). Chest radiographs demonstrated cardiomegaly (72%) and pulmonary artery prominence (71%). Right ventricular hypertrophy was the most common electrocardiographic finding (67%). Dilatation of the right heart chambers was the most common echocardiographic finding (98%). Plexogenic pulmonary arteriopathy was the most common histopathology (78%). Pulmonary function tests demonstrated mild restrictive patterns with variably reduced diffusing capacities. The responses to vasodilator agents and antiretroviral therapy was variable. Sixty-six patients died during a median follow-up period of 8 months. The median length of time from diagnosis to death was 6 months.

CONCLUSION

HIV infection is an independent risk factor for the development of pulmonary hypertension. The appearance of unexplained cardiopulmonary symptoms in HIV-infected individuals should suggest pulmonary hypertension.

Plasma brain natriuretic peptide as a prognostic indicator in patients with primary pulmonary hypertension

BACKGROUND

Plasma brain natriuretic peptide (BNP) level increases in proportion to the degree of right ventricular dysfunction in pulmonary hypertension. We sought to assess the prognostic significance of plasma BNP in patients with primary pulmonary hypertension (PPH).

METHODS AND RESULTS

Plasma BNP was measured in 60 patients with PPH at diagnostic catheterization, together with atrial natriuretic peptide, norepinephrine, and epinephrine. Measurements were repeated in 53 patients after a mean follow-up period of 3 months. Forty-nine of the patients received intravenous or oral prostacyclin. During a mean follow-up period of 24 months, 18 patients died of cardiopulmonary causes. According to multivariate analysis, baseline plasma BNP was an independent predictor of mortality. Patients with a supramedian level of baseline BNP (>/=150 pg/mL) had a significantly lower survival rate than those with an inframedian level, according to Kaplan-Meier survival curves (P<0.05). Plasma BNP in survivors decreased significantly during the follow-up (217+/-38 to 149+/-30 pg/mL, P<0. 05), whereas that in nonsurvivors increased (365+/-77 to 544+/-68 pg/mL, P<0.05). Thus, survival was strikingly worse for patients with a supramedian value of follow-up BNP (>/=180 pg/mL) than for those with an inframedian value (P<0.0001).

CONCLUSIONS

A high level of plasma BNP, and in particular, a further increase in plasma BNP during follow-up, may have a strong, independent association with increased mortality rates in patients with PPH.

From the archives of the AFIP: pulmonary vasculature: hypertension and infarction

Pulmonary hypertension is the hemodynamic consequence of vascular changes within the precapillary (arterial) or postcapillary (venous) pulmonary circulation. These changes may be idiopathic, as in primary pulmonary hypertension or pulmonary veno-occlusive disease, but more commonly they represent a secondary response to alterations in pulmonary blood flow. The pulmonary and systemic bronchial circulations form broad anastomoses that largely prevent infarction except in settings of markedly elevated pulmonary venous pressure, underlying malignancy, or excessive embolic burden. Causes of precapillary pulmonary hypertension include long-standing cardiac left-to-right shunt, chronic thromboembolic disease, and widespread pulmonary embolism arising from intravascular malignant cells, parasites, or foreign materials. The classic radiologic features of precapillary pulmonary hypertension are central arterial enlargement, sharply pruned peripheral vascularity, and right-sided heart hypertrophy and chamber dilatation. Postcapillary pulmonary hypertension may develop secondary to focal venous constriction or to compromised pulmonary venous drainage due to left atrial neoplasia, mitral stenosis, or left ventricular failure. Radiologic manifestations of postcapillary pulmonary hypertension include prominent septal lines, small pleural effusions, and occasionally air-space opacities. In addition, radiologic evaluation of postcapillary pulmonary hypertension may demonstrate evidence of pulmonary arterial hypertension, secondary to the retrograde transmission of elevated pulmonary venous pressure across the capillary bed.

Echocardiographic Evaluation of Patients with Primary Pulmonary Hypertension Before and After Atrial Septostomy

OBJECTIVES: To characterize the early changes in right ventricular [right ventricle (RV)] geometry and function, as assessed by two-dimensional (2-D) and Doppler echocardiography, after balloon-dilation atrial septostomy (BDAS) in patients with severe primary pulmonary hypertension (PPH). BACKGROUND: Survival in PPH is to a great extent dependent on the functional status of the RV. BDAS recently has been shown to improve functional class and hemodynamics in patients with PPH nonresponsive to conventional vasodilator treatment. METHODS: Ten patients with severe PPH who underwent BDAS were studied with transthoracic and transesophageal 2-D and Doppler echocardiography. RV dimensions were measured in the apical four-chamber view. Continuous-wave Doppler echocardiography was used to obtain peak velocity of tricuspid regurgitation. Transesophageal echocardiography (TEE) primarily was used for the follow-up of the atrial septal defects (ASDs). RESULTS: In the early post-BDAS studies, right atrial and ventricular dimensions significantly decreased in all patients (P < 0.05). Global right ventricular wall motion (RVWM) also improved. RV percent change in area after septostomy inversely correlated with the changes in RV systolic area (r = -0.75; P < 0.05) and also with the baseline (preprocedure) values of RV percent change in area (r = -0.77; P < 0.05). Neither RV wall thickness nor the degree of tricuspid regurgitation were modified significantly after the procedure. CONCLUSIONS: BDAS in the setting of severe PPH results in moderate and salutary changes in geometry and function of the RV as assessed by 2-D echocardiography. These changes mainly appear to be the result of the decompression effect of atrial septostomy.

Serum uric acid levels correlate with the severity and the mortality of primary pulmonary hypertension

Serum uric acid (UA), the final product of purine degradation, has been proposed to be a marker for impaired oxidative metabolism and a possible predictor of mortality in patients with chronic heart failure. To elucidate whether serum UA correlates with the severity and the mortality of primary pulmonary hypertension (PPH), serum UA was assessed in 90 patients with PPH together with other clinical variables. Right heart catheterization was performed in all patients. Serum UA was significantly elevated in patients with PPH compared with age-matched control subjects (7.5 +/- 2.5 versus 4.9 +/- 1.2 mg/ml, p < 0.001). Serum UA negatively correlated with cardiac output (r = -0.52, p < 0.001) and positively correlated with total pulmonary resistance (r = 0.57, p < 0.001). Serum UA significantly decreased from 7.1 +/- 1.9 to 5.9 +/- 1.6 mg/dl with vasodilator therapy, associated with a reduction in total pulmonary resistance from 22 +/- 6 to 17 +/- 7 Wood units. During a mean follow-up period of 31 mo, 53 patients died of cardiopulmonary causes. Among noninvasive variables, serum UA was independently related to mortality by a multivariate Cox proportional-hazards analysis. The Kaplan-Meier survival curves according to the median value of serum UA demonstrated that patients with high serum UA had a significantly higher mortality rate than did those with low serum UA (log-rank test, p < 0.01). These results suggest that serum UA increases in proportion to the clinical severity of PPH and has independent association with long-term mortality of patients with PPH.

Radiology of the right ventricle

RV changes may be generalized into dilatation and hypertrophy. Increased preload results in ventricular dilatation. Increased afterload causes hypertrophy. Change in the shape of the RV resulting from increased afterload and myocardial hypertrophy induces tricuspid regurgitation, which superimposes changes of chamber dilatation onto those of hypertrophy. Sustained ventricular dilatation and hypertrophy frequently progresses to RV failure. In these cases, RV systolic function decreases in association with elevation of RV and right atrial diastolic pressure. Changes in the wall thickness and shape of the RV are variable, and depend upon the severity of the volume or pressure load presented, as well as its duration and rate of progression. Because the RV is an anterior cardiac structure, it occupies little of any heart border. Therefore, the sensitivity of plain film examination to RV disease is limited. Inferential diagnosis of RV disease can often be made based upon identification of other radiographic changes, notably the state of the pulmonary circulation, and the position of the heart in the chest. Conventional contrast right ventriculography may be used to assess the size and position of the RV, as well as associated acquired and congenital lesions that result in RV dysfunction. Due to the unusual shape of the RV cavity, however, and the unpredictable manner in which it dilates, accurate quantitative analysis by this technique is limited. Furthermore, the common association between RV disease and pulmonary hypertension limits the applicability of this imaging technique for evaluating patients with RV disease. Multiplanar MR imaging allows direct demonstration of changes in RV size and wall morphology. Furthermore, application of Simpson's rule to tomographic slices acquired at ventricular diastole and systole allows direct, accurate, and reproducible quantitative analysis of ventricular volume and myocardial mass, allowing radiographic assessment in patients for diagnosis, as well as longitudinally during medical management or after surgical treatment for congenital and acquired diseases that result in RV dysfunction.

Value of a Doppler-derived index combining systolic and diastolic time intervals in predicting outcome in primary pulmonary hypertension

Primary pulmonary hypertension is characterized by elevated pulmonary arterial pressure and vascular resistance, frequently producing right heart failure and death. Therefore, the Doppler right ventricular (RV) index, which is a measure of global RV function, could be a useful predictor of outcome in primary pulmonary hypertension. The Doppler RV index, defined as the sum of isovolumic contraction time and isovolumic relaxation time divided by ejection time, was retrospectively measured in 53 patients (38 women, aged 45 +/- 14 years) with primary pulmonary hypertension. Ejection time was measured from the pulmonary outflow velocity signal. The sum of isovolumic contraction time and isovolumic relaxation time was obtained by subtracting ejection time from the duration of tricuspid regurgitation. The Doppler RV index tended to be elevated (median 0.83) compared with normal ranges. Normal Doppler RV index was 0.28 +/- 0.04. After a mean follow-up duration of 2.9 years, 4 patients underwent lung transplantation and 30 patients died; the cause was cardiac in 28, noncardiac in 1, and uncertain in 1. Univariately, the Doppler RV index (chi-square 20.7, p <0.0001), severity of tricuspid regurgitation (chi-square 8.2, p = 0.004), treatment with calcium blockers (chi-square 6.6, p = 0.01), heart rate (chi-square 5.1, p = 0.02), and symptom status (chi-square 4.9, p = 0.03) were associated with adverse outcome (cardiac deaths and lung transplantation). However, only the Doppler RV index and treatment with calcium blockers were independent predictors within the multivariate model. Our results indicate that the Doppler RV index is a useful predictor of adverse outcome in patients with primary pulmonary hypertension.