Survival in patients with primary pulmonary hypertension. Results from a national prospective registry

Primary pulmonary hypertension

Primary pulmonary hypertension (PPH) is a rare disorder characterised by raised pulmonary-artery pressure in the absence of secondary causes. Precapillary pulmonary arteries are affected by medial hypertrophy, intimal fibrosis, microthrombosis, and plexiform lesions. Most individuals present with dyspnoea or evidence of right heart failure. Echocardiography is the best non-invasive test to screen for suspected pulmonary hypertension. The discovery of mutations in the coding region of the gene for bone morphogenetic protein receptor 2 in patients with familial and sporadic PPH may help not only to elucidate pathogenesis but also to direct future treatment options. The pathogenesis is not completely understood, but recent investigations have revealed many possible candidate modifier genes. Without treatment, the disorder progresses in most cases to right heart failure and death. With current therapies such as epoprostenol, progression of disease is slowed, but not halted. Many promising new therapeutic options, including prostacyclin analogues, endothelin-1-receptor antagonists, and phosphodiesterase inhibitors, improve clinical function and haemodynamic measures and may prolong survival.

Pulmonary hypertension: new perspectives

The World Health Organization symposium offers a new treatment-oriented classification of pulmonary hypertension based on an improved understanding of its pathophysiology. Regardless of the etiology, severe or unrelieved pulmonary hypertension leads to right heart failure. Symptoms and signs of pulmonary hypertension are often subtle and nonspecific. As a result, a significant delay between the onset of symptoms and the diagnosis of pulmonary hypertension is common. Echocardiography with Doppler flow is the most useful study to evaluate patients suspected of having pulmonary hypertension. The suspected diagnosis of pulmonary hypertension should then be confirmed by right heart catheterization. If present, further evaluation may include oxygen assessment, pulmonary function testing, high resolution computed tomography of the chest, and ventilation-perfusion lung scanning. Treatment of pulmonary hypertension requires uncommon expertise. General measures include correction of the underlying cause, reversal of hypoxemia and judicious use of diuretics. Advances in vasodilator therapy have increased treatment options beyond calcium channel blockers and intravenous epoprostenol. Lung transplantation remains an option for select patients with pulmonary hypertension not responding to medical management.

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.

Pulmonary function in primary pulmonary hypertension

OBJECTIVES

The study was done to ascertain the degree to which abnormalities in resting lung function correlate with the disease severity of patients with primary pulmonary hypertension (PPH).

BACKGROUND

Patients with PPH are often difficult to diagnose until several years after the onset of symptoms. Despite the seriousness of the disorder, the diagnosis of PPH is often delayed because it is unsuspected and requires invasive measurements. Although PPH often causes abnormalities in resting lung function, these abnormalities have not been shown to be statistically significant when correlated with other measures of PPH severity.

METHODS

Resting lung mechanics and diffusing capacity for carbon monoxide DL(CO) were assessed in 79 patients whose findings conformed to the classical diagnostic criteria of PPH and who had no evidence of secondary causes of pulmonary hypertension. These findings were correlated with severity of disease as assessed by cardiac catheterization, New York Heart Association (NYHA) class, and cardiopulmonary exercise testing.

RESULTS

When PPH patients were first evaluated at our referral clinic, the DL(CO) and lung volumes were decreased in approximately three-quarters and one-half, respectively. The decreases in DL(CO), and to a lesser extent lung volumes, correlated significantly with decreases in peak oxygen uptake (reflecting maximum cardiac output), peak oxygen pulse (reflecting maximum stroke volume), and anaerobic threshold (reflecting sustainable exercise capacity) and higher NYHA class.

CONCLUSIONS

Patients with PPH commonly have abnormalities in lung mechanics and DL(CO) levels that correlate significantly with disease severity. These measurements can be useful in evaluating patients with unexplained dyspnea and fatigue.

Intravascular ultrasound of the elastic pulmonary arteries: a new approach for the evaluation of primary pulmonary hypertension

OBJECTIVE

To assess the structural and functional characteristics of pulmonary arteries by intravascular ultrasound (IVUS) in the setting of primary pulmonary hypertension, and to correlate the ultrasound findings with haemodynamic variables and mortality at follow up.

DESIGN

Prospective observational study.

SETTING

University hospital (tertiary referral centre).

PATIENTS

20 consecutive patients with primary pulmonary hypertension (16 female; mean (SD) age, 39 (14) years).

METHODS

Cardiac catheterisation and simultaneous IVUS of pulmonary artery branches at baseline and after infusion of epoprostenol.

RESULTS

33 pulmonary arteries with a mean diameter of 3.91 (0.80) mm were imaged, and wall thickening was observed in all cases, 64% being eccentric. Mean wall thickness was 0.37 (0.13) mm, percentage wall area 31.0 (9.3)%, pulsatility 14.6 (4.8)%, and pulmonary/elastic strain index 449 (174) mm Hg. No correlation was observed between IVUS findings and haemodynamic variables. Epoprostenol infusion increased pulsatility by 53% and decreased the pulmonary/elastic strain index by 41% (p = 0.0001), irrespective of haemodynamic changes. At 18 (12) months follow up, nine patients had died. A reduced pulsatility and an increased pulmonary/elastic strain index were associated with increased mortality at follow up (12.0 (4.4)% v 16.4 (4.4)%, p = 0.03; 369 (67) v 546 (216) mm Hg, p = 0.02).

CONCLUSIONS

IVUS demonstrated pulmonary artery wall abnormalities in all patients with primary pulmonary hypertension, mostly eccentric. The severity of the changes did not correlate with haemodynamic variables, and epoprostenol improved pulmonary vessel stiffness. There was an association between impaired pulmonary artery functional state as determined by IVUS and mortality at follow up.

[Ten years' experience in continuous intravenous epoprostenol therapy in severe pulmonary arterial hypertension]

INTRODUCTION

Primary pulmonary hypertension and its associated forms is a progressive and often fatal disease, the course of which has been favourably modified by prostacyclin therapy in the last decade.

OBJECTIVE

The aim of this study is to analize retrospectively the efficacy of continuous intravenous epoprostenol (synthetic prostacyclin) therapy in pulmonary arterial hypertension, and to compare it with conventional therapy (anticoagulants, digoxin and diuretics).

METHODS

Between 1990-2000, 31 patients with severe precapillary pulmonary hypertension in functional class III or IV went on continuous intravenous epoprostenol therapy, administered by a portable infusion pump through a Hickman catheter. We compared their survival with a group of 16 patients treated with conventional therapy alone.

RESULTS

Time of follow-up was 33.25 months in the prostacyclin group and 20 months in the conventional group. The one- three- and five- year survival rates were 86%, 50% and 38% respectively for patients treated with epoprostenol compared with 40%, 40% and 8% survival rates at idetical periods for patients treated conventionally (p = 0,02). Functional class and the mean distance walked in the 6 minutes test were improved in patients treated with prostacyclin (p < 0,01). Serious complications attributable to the delivery system included 3 deaths, mainly due to infection.

CONCLUSION

Continuous intravenous epoprostenol therapy improves survival and exercise capacity in patients with severe pulmonary arterial hypertension despite potentially serious complications attributable to the delivery system.

Pulmonary hypertension in sickle cell disease: cardiac catheterization results and survival

Few results on cardiac catheterization have been published for patients with sickle cell disease (SCD) with pulmonary hypertension (PHTN). Their survival once this complication develops is unknown. We analyzed hemodynamic data in 34 adult patients with SCD at right-sided cardiac catheterization and determined the relationship of PHTN to patient survival. In 20 patients with PHTN the average systolic, diastolic, and mean pulmonary artery pressures were 54.3, 25.2, and 36.0 mm Hg, respectively. For 14 patients with SCD without PHTN these values were 30.3, 11.7, and 17.8 mm Hg, respectively. The mean pulmonary capillary wedge pressure in patients with PHTN was higher than that in patients without PHTN (16.0 versus 10.6 mm Hg; P =.0091) even though echocardiography showed normal left ventricular systolic function. Cardiac output was high (8.6 L/min) for both groups of patients. The median postcatheterization follow-up was 23 months for patients with PHTN and 45 months for those without PHTN. Eleven patients (55%) with PHTN died compared to 3 (21%) patients without PHTN (chi(2) = 3.83; P =.0503). The mean pulmonary artery pressure had a significant inverse relationship with survival (Cox proportional hazards modeling). Each increase of 10 mm Hg in mean pulmonary artery pressure was associated with a 1.7-fold increase in the rate (hazards ratio) of death (95% CI = 1.1-2.7; P =.028). The median survival for patients with PHTN was 25.6 months, whereas for patients without PHTN the survival was still over 70% at the end of the 119-month observation period (P =.044, Breslow-Gehan log-rank test). Our findings suggest that PHTN in patients with SCD shortened their survival.

Outcome in 91 consecutive patients with pulmonary arterial hypertension receiving epoprostenol

Epoprostenol has markedly improved the treatment of pulmonary arterial hypertension, although predictors of outcome with epoprostenol are not well characterized. From June 1995 through August 2001, 91 patients with pulmonary arterial hypertension were treated with epoprostenol at our institution. We analyzed the effects of long-term epoprostenol treatment to determine features associated with outcome. Predictors of worse outcome included older age of disease onset (hazard ratio 3.2, 95% confidence interval 1.32-7.76 for patients above the median age of 44 years), World Health Organization functional Class IV, either at baseline or follow-up, (3.07, 1.42-6.62 compared with functional Class I, II, and III), and scleroderma spectrum of disease (2.32, 1.08-4.99). There were no baseline or follow-up hemodynamic factors predictive of outcome. Our results indicate that treatment with epoprostenol improves survival in patients with Primary Pulmonary Hypertension compared with that predicted by the National Institutes of Health Primary Pulmonary Hypertension Registry's survival equation and that their survival is significantly better than that of patients with scleroderma spectrum of disease (p = 0.001). Older patients treated with epoprostenol have significantly shorter survival, regardless of etiology.

Prostacyclin for pulmonary hypertension

BACKGROUND

Primary pulmonary hypertension (PPH) is progressive, resulting in right ventricular failure. Survival seldom exceeds five years. Pulmonary hypertension can be idiopathic or associated with other conditions. It is common in patients with diffuse scleroderma and the CREST syndrome where it is clinically, haemodynamically and prognostically indistinguishable from idiopathic primary pulmonary hypertension. Prostacyclin is a potent vasodilator and inhibitor of platelet aggregation. Iloprost is a chemically stable derivative of prostacyclin with similar biologic properties and can be given orally, by infusion or nebulised.

OBJECTIVES

To determine the efficacy of prostacyclin or one of its analogues in idiopathic primary pulmonary hypertension.

SEARCH STRATEGY

A search was carried out using the Cochrane controlled clinical trial register. An update search was conducted on 12th August 2002. Four new trials met the inclusion criteria of the review.

SELECTION CRITERIA

Randomised controlled trials (RCTs) involving patients with primary pulmonary hypertension or pulmonary hypertension secondary to connective tissue disorders were selected by two reviewers.

DATA COLLECTION AND ANALYSIS

Study quality was assessed and data extracted independently by two reviewers. Outcomes were analysed as continuous and dichotomous outcomes, using standard statistical techniques.

MAIN RESULTS

Seven RCTs of short duration (8-12 weeks) were included. Three compared intravenous epoprostenol with conventional therapy. One compared intravenous Iloprost with placebo. One RCT compared oral prostacyclin with placebo, another compared subcutaneous infusion of treprostinil with placebo and a further RCT studied the effects of inhaled iloprost. All the trials showed an improvement in exercise capacity. Cardiopulmonary haemodynamics, dyspnoea scores and symptoms also improved in some of the studies. Side effects and adverse events related to the indwelling catheter (sepsis and thrombosis) were common in intravenous trials. The other routes of administration had less severe side effects.

REVIEWER'S CONCLUSIONS

Intravenous prostacyclin or one of its analogues in addition to conventional therapy over 12 weeks appears to improve exercise capacity, NYHA functional class and several cardiopulmonary haemodynamic variables. There is some evidence that other routes of administration of the drug may also be effective with fewer side effects, which were mainly related to the indwelling catheter.

Pulmonary hypertension associated with connective tissue disease

Pulmonary arterial hypertension is a life threatening complication of several connective tissue diseases including scleroderma (both diffuse and limited scleroderma, or the CREST syndrome--calcinosis cutis, Raynaud's phenomenon, esophageal dysfunction, sclerodactyly, and telangectasia), systemic lupus erythomatosis (SLE), mixed connective tissue disease (MCTD), and less commonly, rheumatoid arthritis (RA) and dermatomyositis/polymyositis. This report reviews the occurrence of this complication, potential etiologies, clinical presentation, and treatment options.

Usefulness and limits of transthoracic echocardiography in the evaluation of patients with primary and chronic thromboembolic pulmonary hypertension

The aim of the study was to evaluate the potential usefulness of transthoracic echocardiography in differentiating patients with primary or chronic thromboembolic pulmonary hypertension and to define the capability of echocardiography to assess right-heart performance in such patients. Right-heart catheterization and ultrasound examination were performed in 111 patients with chronic thromboembolic pulmonary hypertension and in 31 patients with primary pulmonary hypertension. All echocardiographic and Doppler parameters were similar in primary and chronic thromboembolic pulmonary hypertension. A significant correlation was found between the tricuspid annular plane systolic excursion and the right ventricular fractional area change and thermodilution-derived right ventricular ejection fraction (P <.001 for both). Furthermore, different patterns of the pulsed Doppler flow velocity curve into the superior vena cava were associated with different right-heart hemodynamic profiles. In conclusion, in patients with chronic pulmonary hypertension transthoracic echocardiography portends meaningful information on the capability of the right heart to confront the increased afterload but it does not permit etiologic differentiation.

Significance of a plasma D-dimer test in patients with primary pulmonary hypertension

BACKGROUND

D-dimer, a degradation product of fibrin, has been increasingly used as a marker or prognostic factor in various thrombotic diseases.

OBJECTIVE

To assess the significance of a d-dimer test in patients with primary pulmonary hypertension (PPH).

PATIENTS AND METHODS

Fourteen patients with PPH (12 women and 2 men) aged 25 to 68 years (mean +/- SD age, 50 +/- 14 years) entered the study. Plasma d-dimer was determined by Miniquant assay (Biopool International; Venture, CA) 3 +/- 5 months after the disease onset, and patients were followed up for 1 year. We compared the d-dimer levels to the demographic, clinical, and hemodynamic data of the patients.

RESULTS

D-dimer levels were positively correlated with New York Heart Association classification (r = 0.59, p = 0.01) and pulmonary artery pressure (r = 0.43, p = 0.03) and were negatively correlated with oxygen saturation (r = - 0.45, p = 0.03) and 6-min walk distance (r = - 0.49, p = 0.04). One-year survival was also negatively correlated with d-dimer (point-biserial r = - 0.71, p = 0.004), with a higher d-dimer value associated with poorer survival. No significant correlations were found between d-dimer values and sex, age, diffusing capacity of the lung for carbon monoxide, or cardiac index.

CONCLUSION

D-dimer levels may have a role in the evaluation of patients with PPH. This simple, noninvasive test may be helpful for identifying patients who are at a higher risk for severe disease.

Aerosolized vasodilators in pulmonary hypertension

Pulmonary hypertension is a life-threatening disease characterized by an increase in artery pressure and vascular resistance in the pulmonary circulation. A primary form of pulmonary hypertension with unknown causes is to be distinguished from the far more frequent secondary forms based on known pulmonary and extrapulmonary disorders. An imbalance in the synthesis of vasoconstrictive and vasodilative agents seems to play an important role in the etiology of pulmonary hypertension. This pathophysiological background offers the possibility to develop treatment strategies, including application of vasodilative drugs. The intravenous administration of vasodilative agents, however, lacks pulmonary selectivity leading to systemic side effects. Therefore, the application of aerosol techniques for alveolar deposition of vasodilatory drugs was proposed and several studies with inhaled iloprost, a stable prostacyclin analogue, demonstrated preferential vasorelaxation in the pulmonary circulation, with the maximum pulmonary vasodilatory potency corresponding to that of intravenous prostacyclin. Clinical experiences with long-term inhaled iloprost are available showing sustained effects on exercise capacity and pulmonary hemodynamics in patients with pulmonary hypertension. Due to the necessary frequent inhalations (up to 12 times a day) and the potency of the prostaglandins, the choice of the nebulizer is critical, requiring physical characterization and device comparison studies under the right heart-catheter conditions. The concept of aerosolized vasodilators is meanwhile well established and offers a promising perspective in the treatment of pulmonary hypertension.

Right atrial size and tricuspid regurgitation severity predict mortality or transplantation in primary pulmonary hypertension

Primary pulmonary hypertension (PPH) is a fatal illness. In advanced stages only transplantation is able to increase survival. Echocardiography is useful for the assessment of these patients, but there is limited information about its prognostic value. With this goal, 25 consecutive patients, age: 36.7 +/- 12.7 years, were studied and followed up for a mean period of 29 months (range: 0.2-84). Eleven echocardiographic parameters of cardiac anatomy, function, and hemodynamics were assessed. Age and sex were also analyzed. Death and heart-lung transplantation were considered end-points. Thirteen events (Death: 8; transplantation: 5) occurred in the follow-up (11 of 13 in the first year). Kaplan-Meier estimated survival free from transplantation at 5 years was 40% (95% CI: 23%-70%). In the univariate analysis, RAA (HR: 1.1, P =.0004), TR (HR: 2.7, P =.02), and RVET (HR: 0.98, P =.02) showed statistically significant relation with survival free from transplantation. Multivariate analysis showed that RAS (HR: 1.10, 95% CI: 1.04-1.17, P =.001) and TR (HR: 2.52, 95% CI: 1.01-6.3, P =.047) were independent risk factors of transplantation and death. The use of these findings on the management of patients with PPH should be tested in larger studies.

Survival in primary pulmonary hypertension: the impact of epoprostenol therapy

BACKGROUND

Primary pulmonary hypertension (PPH) is a severe and progressive disease. Without treatment, the median survival is 2.8 years, with survival rates of 68%, 48%, and 34% at 1, 3, and 5 years, respectively. Intravenous epoprostenol was the first Food and Drug Administration-approved therapy for PPH. The long-term impact that epoprostenol has made on PPH remains to be defined.

METHODS AND RESULTS

One hundred sixty-two consecutive patients diagnosed with PPH and treated with epoprostenol were followed for a mean of 36.3 months (median, 31 months). Data including functional class, exercise tolerance, and hemodynamics were recorded in a customized database. Vital status was verified in each patient. Observed survival with epoprostenol therapy at 1, 2, and 3 years was 87.8%, 76.3%, and 62.8% and was significantly greater than the expected survival of 58.9%, 46.3%, and 35.4% based on historical data. Baseline predictors of survival included exercise tolerance, functional class, right atrial pressure, and vasodilator response to adenosine. Predictors of survival after the first year of therapy included functional class and improvement in exercise tolerance, cardiac index, and mean pulmonary artery pressure.

CONCLUSIONS

Intravenous epoprostenol improves long-term survival in PPH.

Primary pulmonary hypertension and cor pulmonale

Primary pulmonary hypertension and cor pulmonale represent forms of precapillary pulmonary hypertension due to intrinsic lung disease. In the case of primary pulmonary hypertension, this is due to disease of the pulmonary vasculature while cor pulmonale is related to diseases of the pulmonary vasculature, airways, or interstitium. Patients present with signs and symptoms of right ventricular dysfunction and low cardiac output including dyspnea, chest pain and peripheral edema. Therapy is directed at the underlying disease and may include supplemental oxygen for diseases causing chronic hypoxemia and anticoagulation for thrombotic disease. Vasodilator therapy has variable efficacy for pulmonary vascular disorders. Postacyclin by continuous infusion has been a major advance in the therapy of primary pulmonary hypertension and has prolonged survival and delayed the need for lung transplantation. Bosentan, an endothelin receptor blocking agent is the first oral medication approved for the therapy of pulmonary hypertension.

Current and emerging therapy for primary pulmonary hypertension

OBJECTIVE

To review the epidemiology, pathophysiology, clinical symptoms, and diagnostic workup of primary pulmonary hypertension (PPH) and to discuss the available data on the current and emerging therapies being used to treat this disorder.

DATA SOURCES

Primary and review articles were identified with a MEDLINE search (1966-December 2001) and through secondary sources.

STUDY SELECTION AND DATA EXTRACTION

All articles identified from the data sources were evaluated and all information deemed relevant was included in this review.

DATA SYNTHESIS

In the absence of a definable cause, PPH is a disorder classified by a progressive increase in pulmonary vascular resistance and mean pulmonary artery pressure. A relatively rare condition, PPH has an annual incidence of 1-2 cases per million people, slightly higher in women than men. The prognosis is poor, with a mean survival time of 2.8 years after diagnosis if untreated. Vasoconstriction, vascular remodeling, and thrombosis are hallmarks of the disease process. Anticoagulation and vasodilators are the most commonly employed treatment options, showing benefits in clinical outcomes, hemodynamic parameters, and mortality. Several new vasodilators are being evaluated for the treatment of PPH. Bosentan was recently approved as the first oral agent for the treatment of PPH. Iloprost, treprostinil, and beraprost are investigational agents in Phase III studies.

CONCLUSIONS

Until additional studies and experience with these agents become available, calcium-channel blockers (CCBs) remain the first option for therapy. For patients not responding to CCBs, therapeutic options will now include epoprostenol and bosentan. Since there are no comparison trials between these 2 agents, therapeutic decisions should be based on patient-specific concerns. Clinical data and experience support the use of epoprostenol; however, in patients at risk or considered unsuitable candidates, bosentan may become a preferred option. Additional studies are warranted to address the potential therapeutic benefits of combination therapy and long-term benefits of agents to treat PPH.

Primary pulmonary hypertension: Current therapy

Because the causes of primary pulmonary hypertension (PPH) remains unknown, the therapeutic approach of the disease can be only empirical, based on the pathology and pathobiology of pulmonary circulation. Despite the inability to cure the disease, therapeutic advances over the past 20 years have contributed to an improvement of quality of life and prolonged survival in PPH patients. Current therapeutic approach of PPH mostly includes limitation of physical activity, long-term anticoagulation, and vasodilator therapy. Among all tested oral vasodilators, calcium-channel blockers are the most efficient long-term therapies by improving symptoms and hemodynamics in a subset of PPH patients (10% to 15%) who acutely respond to such drugs. Acute pulmonary vasodilator response to inhalation of nitric oxide can predict acute and chronic responses to oral calcium-channel blockers. A better understanding of the pathogenesis of PPH has changed the focus of medical treatments from purely chronic vasodilator therapy to the evaluation of agents, such as prostaglandins, that may reverse the proliferation of pulmonary vascular cells and result in regression of the pulmonary vascular hypertrophy and remodeling. Long-term treatment with intravenous epoprostenol (prostaglandin I(2) or prostacyclin) improves exercise capacity, hemodynamics and survival in most patients with PPH in functional class NYHA III or IV, and may be currently considered as the "gold standard" therapy for severe patients. However, response to long-term epoprostenol therapy may be incomplete, adverse effects are common, and survival remains unsatisfactory (55% at 5 years). In such patients with severe pulmonary hypertension refractory to medical therapy, atrioseptostomy and lung transplantation can be indicated.

Long-term intravenous epoprostenol infusion in primary pulmonary hypertension: prognostic factors and survival

OBJECTIVES

We sought to determine the factors associated with long-term survival in patients with primary pulmonary hypertension (PPH) treated with continuous epoprostenol infusion.

BACKGROUND

Epoprostenol improves survival in patients with PPH in New York Heart Association (NYHA) functional class III or IV. However, some patients do not benefit from epoprostenol and must be considered for lung transplantation. The best timing for listing these patients on a lung transplantation program is currently unknown.

METHODS

Between December 1992 and January 2001, 178 patients with PPH in NYHA functional class III or IV were treated with epoprostenol. The 6-min walk test (WT) and right-sided heart catheterization were performed at baseline, after three months on epoprostenol and thereafter once a year.

RESULTS

Overall survival rates at one, two, three, and five years were 85%, 70%, 63%, and 55%, respectively. On univariate analysis, the baseline variables associated with a poor outcome were a history of right-sided heart failure, NYHA functional class IV, 6-min WT <or=250 m (median value), right atrial pressure >or=12 mm Hg, and mean pulmonary artery pressure <65 mm Hg. On multivariate analysis, including both baseline variables and those measured after three months on epoprostenol, a history of right-sided heart failure, persistence of NYHA functional class III or IV at three months, and the absence of a fall in total pulmonary resistance of >30%, relative to baseline, were associated with poor survival.

CONCLUSIONS

Survival of patients with PPH treated with epoprostenol depends on the severity at baseline, as well as the three-month response to therapy. These findings suggest that lung transplantation should be considered in a subset of patients who remain in NYHA functional class III or IV or in those who cannot achieve a significant hemodynamic improvement after three months of epoprostenol therapy, or both.

Assessment of survival in patients with primary pulmonary hypertension: importance of cardiopulmonary exercise testing

BACKGROUND

Primary pulmonary hypertension (PPH) is a life-threatening disease. Prognostic assessment is an important factor in determining medical treatment and lung transplantation. Whether cardiopulmonary exercise testing data predict survival has not been reported previously.

METHODS AND RESULTS

We studied 86 patients with PPH (58 female, age 46+/-2 years, median NYHA class III) between 1996 and 2001 who were followed up in a tertiary referral center. Right heart catheterization was performed and serum uric acid levels were measured in all patients. Seventy patients were able to undergo exercise testing. At the start of the study, the average pulmonary artery pressure was 60+/-2 mm Hg, average pulmonary vascular resistance was 1664+/-81 dyne x s x cm(-5), average serum uric acid level was 7.5+/-0.35 mg/dL, and average peak oxygen uptake during exercise (peak VO(2) was 11.2+/-0.5 mL x kg(-1) x min(-1). During follow-up (mean: 567+/-48 days), 28 patients died and 16 underwent lung transplantation (1-year cumulative event-free survival: 68%; 95% CI 58 to 78). The strongest predictors of impaired survival were low peak VO(2) (P<0.0001) and low systolic blood pressure at peak exercise (peak SBP; P<0.0001). In a multivariable analysis, serum uric acid levels (all P<0.005) and diastolic blood pressure at peak exercise independently predicted survival (P<0.05). Patients with peak VO(2) < or =10.4 mL x kg(-1) x min(-1) and peak SBP < or =120 mm Hg (ie, 2 risk factors) had poor survival rates at 12 months (23%), whereas patients with 1 or none of these risk factors had better survival rates (79% and 97%, respectively).

CONCLUSIONS

Peak VO(2) and peak SBP are independent and strong predictors of survival in PPH patients. Hemodynamic parameters, although also accurate predictors, provide no independent prognostic information.

[Clinico-hemodynamic study and treatment of 44 patients with primary pulmonary hypertension]

BACKGROUND

Primary pulmonary hypertension is a poorly understood disease with a difficult treatment.

PATIENTS AND METHOD

Retrospective study of a series of 44 patients suffering from pulmonary hypertension who were studied in our center between 1992 and 2000.

RESULTS

At diagnosis, 6 (13%) patients were classified as having NYHA functional class I, 11 (25%) had class II, 25 (57%) had class III, and 2 had class IV. Mean pulmonary artery systolic pressure by echo-doppler was 92 (range: 43-154) mmHg. Basal right catheterization showed a mean (SD) pulmonary artery pressure of 58 (18) mmHg, total basal pulmonary resistances of 1679 (1,071) din/cm2 and cardiac index of 2.2 (1) 1/minute/m2. Five patients improved with anticoagulation and calcium channel blockers therapy. Since 1998, 11 patients had been treated with continuous endovenous epoprostenol, yet only 3 (27%) had significant clinical improvement. Survival at 5 years after diagnosis was 56%. At the end of study, 7 (70%) out of 10 patients who underwent pulmonary transplantation were alive (mean: 34, range: 3-62 months).

CONCLUSIONS

Pulmonary hypertension is a disease with a poor prognosis. However, treatment with prostaglandins and pulmonary transplantation may lead to encouraging results.

Oral sildenafil is an effective and specific pulmonary vasodilator in patients with pulmonary arterial hypertension: comparison with inhaled nitric oxide

BACKGROUND

The prognosis of patients with severe pulmonary hypertension (PHT) is poor. To determine prognosis and guide therapy, an acute hemodynamic trial of selective pulmonary vasodilators, usually inhaled nitric oxide (iNO), was performed. We hypothesized that oral sildenafil, a phosphodiesterase-5 inhibitor, is a safe and effective alternative to iNO.

METHODS AND RESULTS

We studied 13 consecutive patients (mean+/-SEM, 44+/-2 years of age; 9 women) referred for consideration of heart-lung transplantation or as a guide to medical therapy. All but one were functional class III or IV. Patients had primary PHT (n=9), pulmonary arterial hypertension (n=2), or secondary PHT (n=2). Hemodynamics and serum cyclic guanosine-monophosphate levels (cGMP) were measured at baseline and at peak effects of iNO (80 ppm), sildenafil (75 mg), and their combination. The decrease in pulmonary vascular resistance was similar with iNO (-19+/-5%) and sildenafil (-27+/-3%), whereas sildenafil+iNO was more effective than iNO alone (-32+/-5%, P<0.003). Sildenafil and sildenafil+iNO increased cardiac index (17+/-5% and 17+/-4%, respectively), whereas iNO did not (-0.2+/-2.0%, P<0.003). iNO increased, whereas sildenafil tended to decrease, pulmonary capillary wedge pressure (+15+/-6 versus -9+/-7%, P<0.0007). Systemic arterial pressure was similar among groups and did not decrease with treatment. cGMP levels increased similarly with iNO and sildenafil, and their combination synergistically elevated cGMP (P<0.0001).

CONCLUSIONS

A single oral dose of sildenafil is as effective and selective a pulmonary vasodilator as iNO. Sildenafil may be superior to iNO in that it increases cardiac output and does not increase wedge pressure. Future studies are indicated to establish whether sildenafil could be effective over a longer duration.

Hemodynamic effects of aerosolized iloprost in pulmonary hypertension at rest and during exercise

STUDY OBJECTIVES

Aerosolized iloprost, a stable prostacyclin analog, improves functional capacity even in patients with pulmonary hypertension who did not show a vigorous hemodynamic response after iloprost inhalation at rest. We therefore speculated that aerosolized iloprost elicits more beneficial effects on pulmonary hemodynamics during exercise than at rest.

DESIGN AND SETTING

A prospective, open, uncontrolled study at a university hospital.

PATIENTS

Sixteen patients with primary or secondary pulmonary hypertension.

INTERVENTIONS

Right-heart catheterization at rest and during exercise before and after the inhalation iloprost, 14 to 28 microg.

RESULTS

Before iloprost treatment, exercise increased mean (+/- SD) pulmonary artery pressure (PAPm) from 45 +/- 8 to 70 +/- 13 mm Hg, cardiac output from 3.7 +/- 1.0 to 5.8 +/- 2.4 L/min, and pulmonary vascular resistance (PVR) from 904 +/- 322 to 1,013 +/- 432 dyne.s.cm(-5) (each p < 0.05). After recovery, iloprost reduced PAPm from 44 +/- 8 to 41 +/- 6 mm Hg, increased cardiac output from 3.7 +/- 1.0 to 4.9 +/- 1.4 L/min, and lowered PVR from 902 +/- 350 to 636 +/- 248 dyne x s x cm(-5) (each p < 0.05). During exercise after iloprost, PAPm increased to 57 +/- 8 mm Hg, cardiac output to 7.0 +/- 3.0 L/min, and PVR to 673 +/- 279 dyne x s x cm(-5) (each p < 0.05 vs first exercise test). Systemic BP was not altered significantly by iloprost treatment during exercise.

CONCLUSIONS

Aerosolized iloprost treatment exerts more favorable effects on pulmonary hemodynamics during exercise than at rest. These findings explain the functional improvement observed in patients with pulmonary hypertension who show only a moderate pulmonary vasodilatory response during iloprost inhalation at rest. Whether these beneficial effects have prognostic significance needs to be elucidated by further study.

Effects of beraprost sodium, an oral prostacyclin analogue, in patients with pulmonary arterial hypertension: a randomized, double-blind, placebo-controlled trial

OBJECTIVES

The purpose of this study was to assess the efficacy and safety of beraprost sodium, an orally active prostacyclin analogue, in New York Heart Association (NYHA) functional class II and III patients with pulmonary arterial hypertension (PAH).

BACKGROUND

Pulmonary arterial hypertension is a life-threatening disease for which continuous intravenous infusion of prostacyclin has been proven effective. However, this treatment is associated with serious complications arising from the complex delivery system.

METHODS

In this double-blind, placebo-controlled study, 130 patients with PAH were randomized to the maximal tolerated dose of beraprost (median dose 80 microg four times a day) or to placebo for 12 weeks. The primary end point was the change in exercise capacity assessed by the 6-min walk test. Secondary end points included changes in Borg dyspnea index, cardiopulmonary hemodynamics and NYHA functional class.

RESULTS

Patients treated with beraprost improved exercise capacity and symptoms. The difference between treatment groups in the mean change of 6-min walking distance at week 12 was 25.1 m (95% confidence interval [CI]: 1.8 to 48.3, p = 0.036). The difference in the mean change of Borg dyspnea index was -0.94 (95% CI: -1.63 to -0.24, p = 0.009). In the sub-group of patients with primary pulmonary hypertension, the difference in the mean change of 6-min walking distance was 46.1 m (95% CI: 3.0 to 89.3, p = 0.035). Cardiopulmonary hemodynamics and NYHA functional class had no statistically significant changes. Drug-related adverse events were common in the titration phase and decreased in the maintenance period.

CONCLUSIONS

Beraprost improves exercise capacity and symptoms in NYHA functional class II and III patients with PAH and, in particular, in those with primary pulmonary hypertension.

Echocardiographic predictors of adverse outcomes in primary pulmonary hypertension

OBJECTIVES

The aim of this study was to evaluate the relationships between echocardiographic findings and clinical outcomes in patients with severe primary pulmonary hypertension (PPH).

BACKGROUND

Primary pulmonary hypertension is associated with abnormalities of right heart structure and function that contribute to the poor prognosis of the disease. Echocardiographic abnormalities associated with PPH have been described, but the prognostic significance of these findings remains poorly characterized.

METHODS

Echocardiographic studies, invasive hemodynamic measurements and 6-min walk tests were performed and outcomes prospectively followed in 81 patients with severe PPH. Subjects were participants in a 12-week randomized trial examining the effects of prostacyclin plus conventional therapy compared with conventional therapy alone.

RESULTS

During the mean follow-up period of 36.9 +/- 15.4 months, 20 patients died and 21 patients underwent transplantation. Pericardial effusion (p = 0.003) and indexed right atrial area (p = 0.005) were predictors of mortality. Pericardial effusion (p = 0.017), indexed right atrial area (p = 0.012) and the degree of septal shift in diastole (p = 0.004) were predictors of a composite end point of death or transplantation. In multivariable analyses incorporating clinical, hemodynamic and echocardiographic variables, pericardial effusion and an enlarged right atrium remained predictors of adverse outcomes. Six-minute walk results, mixed venous oxygen saturation and initial treatment randomization were also independently associated with a poor prognosis.

CONCLUSIONS

Pericardial effusion, right atrial enlargement and septal displacement are echocardiographic abnormalities that reflect the severity of right heart failure and predict adverse outcomes in patients with severe PPH. These characteristics may help identify patients appropriate for more intensive medical therapy or earlier transplantation.

Current management of primary pulmonary hypertension

Primary pulmonary hypertension (PPH) is a rare disorder of the lung vasculature characterised by an increase in pulmonary artery pressure. Although the aetiology of this disease remains unknown, knowledge of the pathophysiology of the disease has advanced considerably. Diagnosis of PPH is largely by exclusion. The clinical symptoms associated with PPH are aspecific and similar to those seen in other cardiovascular and pulmonary diseases. Electrocardiography, echocardiography, pulmonary function tests, and a lung perfusion scan are necessary to exclude secondary forms of pulmonary hypertension and also help to confirm the diagnosis of PPH. A definite diagnosis of PPH is established by right-heart catheterisation which gives a precise measure of the blood pressure in the right side of the heart and the pulmonary artery, right ventricular function and cardiac output. Once a diagnosis of PPH is established, treatment involving drug therapy or surgery is commenced on the basis of the New York Heart Association functional class. Conventional treatment consists of lifetime administration of anticoagulants, oxygen, diuretics, and digoxin. Vasodilator therapy with calcium channel antagonists is indicated in patients who are 'vasoreactive' to acute vasodilator challenge as assessed by right-heart catheterisation. Promising results are obtained by continuous intravenous administration of epoprostenol (prostacyclin). Newer therapies for PPH include prostacyclin analogues, endothelin receptor antagonists, nitric oxide, phosphodiesterase-5 inhibitors, elastase inhibitors, and gene therapy. Surgical treatment consists of atrial septostomy, thromboendarterectomy, and lung or heart-lung transplantation.

Continuous subcutaneous infusion of treprostinil, a prostacyclin analogue, in patients with pulmonary arterial hypertension: a double-blind, randomized, placebo-controlled trial

Pulmonary arterial hypertension is a life-threatening disease for which continuous intravenous prostacyclin has proven to be effective. However, this treatment requires a permanent central venous catheter with the associated risk of serious complications such as sepsis, thromboembolism, or syncope. Treprostinil, a stable prostacyclin analogue, can be administered by a continuous subcutaneous infusion, avoiding these risks. We conducted a 12-week, double-blind, placebo-controlled multicenter trial in 470 patients with pulmonary arterial hypertension, either primary or associated with connective tissue disease or congenital systemic-to-pulmonary shunts. Exercise capacity improved with treprostinil and was unchanged with placebo; the between treatment group difference in median six-minute walking distance was 16 m (p = 0.006). Improvement in exercise capacity was greater in the sicker patients and was dose-related, but independent of disease etiology. Concomitantly, treprostinil significantly improved indices of dyspnea, signs and symptoms of pulmonary hypertension, and hemodynamics. The most common side effect attributed to treprostinil was infusion site pain (85%) leading to premature discontinuation from the study in 8% of patients. Three patients in the treprostinil treatment group presented with an episode of gastrointestinal hemorrhage. We conclude that chronic subcutaneous infusion of treprostinil is an effective treatment with an acceptable safety profile in patients with pulmonary arterial hypertension.

Current management of primary pulmonary hypertension

Primary pulmonary hypertension (PPH) is a rare disorder with an annual incidence of 1 to 2 per million people. The aetiology of this disorder is unknown, but it appears to result from an abnormal interaction of environmental and genetic factors leading to a vasculopathy. The pulmonary arteries in these patients exhibit a spectrum of pathological lesions ranging from the early medial hypertrophy to the end-stage fibrotic plexiform lesions. This characteristic pathology is also observed in pulmonary hypertension resulting from connective tissue disease (particularly systemic sclerosis), HIV infection, portal hypertension and certain toxins. PPH is a condition that is difficult to diagnose and treat, with a median survival of 2.8 years in historical studies. One of the difficulties in treating patients with PHH is that the subacute nature of disease presentation often prevents an accurate diagnosis during the early stages of the illness. Progressive dyspnoea on exertion is the most common presenting symptom. Diagnostic evaluation should include electrocardiography, chest radiograph and echocardiography, and laboratory and other studies to evaluate for secondary causes (e.g. pulmonary function tests, chest computed tomography and ventilation/perfusion scans, pulmonary arteriogram, cardiopulmonary testing, right heart catherisation). PHH is a disorder for which there is no known cure. Current medical and surgical treatment options for patients with PHH include anticoagulation, vasodilators and transplantation. Calcium channel antagonists are currently the oral drugs of choice for the treatment of patients with New York Heart Association (NYHA) Class II disease. These agents, in particular the dihydropyridine compounds, have beneficial effects on haemodynamics and right ventricular function, and possibly increased survival. Epoprostenol is administered by intravenous infusion, and studies have demonstrated short- and long-term improvements in symptoms, haemodynamics and survival. It is well tolerated and has become the treatment of choice for patients with NYHA Class III and IV disease. Inotropic agents are used as a bridge to transplant, which is indicated in patients who do not respond to maximal medical therapy. Experience has shown that single lung, double lung and heart-lung transplantation are approximately of equal efficacy. Currently, single lung transplant appears to be the procedure of choice. Newer agents, such as sildenafil, beraprost and bosentan, are presently being evaluated for the treatment of this disorder. Future study should include elucidation of the pathogenic mechanisms in the development of this vasculopathy, which will hopefully lead to the development of improved treatment options for patients with PHH.

Recovery of cardiac function after living-donor lung transplantation in a patient with primary pulmonary hypertension

Legislation for brain death and organ transplantation was passed in Japan in 1997, but there is still a great shortage of brain-death donors. Primary pulmonary hypertension (PPH) is a progressive disease that is usually followed by death within 5 years of diagnosis. Continuous infusion of prostacyclin is effective, but some patients will ultimately require heart-lung or lung transplantation. The first case of bilateral living-donor lobar lung transplantation (LDLLT) for PPH in Japan is reported. The recipient was a 19-year-old woman who was diagnosed as PPH at the age of 14 years and began intravenous prostacyclin therapy. Initially her symptoms improved, but she returned to New York Heart Association class IV in 2000. In January 2001, she underwent bilateral LDLLT. Postoperative echocardiography showed that the right ventricular diameter had decreased and septal wall motion had normalized, resulting in a round-shaped left ventricle. Right heart catheterization demonstrated that cardiac output and pulmonary arterial pressure had normalized. The right ventricular ejection fraction improved from 15% to 77%. The patient was discharged from hospital after 60 days postoperatively. LDLLT will become one of the options in Japan for end-stage PPH.

Outcome after cardiopulmonary resuscitation in patients with pulmonary arterial hypertension

Patients with pulmonary arterial hypertension (PAH) often die from right heart failure or sudden cardiac death. Cardiopulmonary resuscitation (CPR) may be instituted in these patients but there are no data in the medical literature about the outcome of CPR in this group of patients. We conducted a retrospective multicenter international study on the frequency and results of CPR in patients with PAH. A total of 3,130 patients with PAH were treated between 1997 and 2000 in 17 referral centers in Europe and in the United States. During this period, 513 patients had circulatory arrest and CPR was attempted in 132 (26%) of these patients. Although 96% of the CPR attempts took place in hospitalized patients (74% in intensive care units or equally equipped facilities) and although there was only minimal delay between collapse and initiation of CPR, resuscitation efforts were primarily unsuccessful in 104 patients (79%). Only eight patients (6%) survived for more than 90 d; these patients had no residual neurologic deficit. Hemodynamics obtained within 3 mo before CPR did not show any significant differences between the survivors and nonsurvivors. Except for one patient, all long-term survivors had identifiable causes of circulatory arrest that were rapidly reversible. Our data indicate that CPR for circulatory arrest in patients with PAH is rarely successful unless the cause of the cardiopulmonary decompensation can be corrected.

Right ventricular dP/dt/P(max), not dP/dt(max), noninvasively derived from tricuspid regurgitation velocity is a useful index of right ventricular contractility

BACKGROUND

Although right ventricular (RV) contractility is important in determining functional capacity, few quantification methods are clinically available. RV dP/dt(max) can be assessed by Doppler echocardiography by using tricuspid regurgitation (TR) but is not routinely used because of its dependency on a Doppler incident angle and preload. Doppler-derived dP/dt/P(max) is relatively insensitive to preload and theoretically independent of the incident angle. We investigated the clinical feasibility of this index as an RV contractility index.

METHODS

We computed RV dP/dt(max) and dP/dt/P(max) from the TR-derived RV pressure in 68 patients with dominant RV failure (13 in New York Heart Association [NYHA] class I, 33 in class II, 17 in class III, and 5 in class IV). Peak oxygen consumption (peak VO(2)) was measured in 20 patients during a maximal bicycle ergometer test.

RESULTS

dP/dt(max) did not significantly correlate with NYHA class. In contrast, dP/dt/P(max) decreased monotonically with the functional class (r = -0.49, P <.0001), and correlated with peak VO(2) (r = 0.66, P <.002).

CONCLUSION

TR-derived dP/dt/P(max), not dP/dt(max), is a clinically useful index of RV contractility, allowing researchers to account for the functional capacity.

Epoprostenol-induced pulmonary vasodilatation in patients with pulmonary hypertension measured by electrical impedance tomography

Electrical impedance tomography (EIT) has been proposed as a method to monitor dynamic changes in the pulmonary vascular bed. In this study we examined the validity of EIT in the measurement of pulmonary vasodilatation in eight patients with primary and secondary pulmonary hypertension when given the vasodilating agent epoprostenol (Flolan). Therefore, catheterization of the pulmonary artery was performed in the ICU and the cardiac output was measured by means of the Fick method. The pulmonary vascular resistance (PVR) and mean pulmonary arterial pressure (mPAP) were determined. Epoprostenol was given in increasing doses to test reversibility of pulmonary hypertension. The maximum test dose was 12 ng kg(-1) min(-1). During each step simultaneous EIT (DAS-01 P Portable Data Acquisition System, Sheffield, England) measurements were performed with the 16 electrodes equidistantly positioned in the third intercostal space. The maximal systolic impedance change, relative to end-diastole, deltaZperf, was chosen as a measure of pulmonary perfusion. The impedance change between baseline and highest tolerable epoprostenol concentration was compared with the change in PVR. The mean PVR (dyn s/cm5) decreased from 636 (+/-399) to 366 (+/-242); p < 0.01. DeltaZperf (in arbitrary units) for the whole patient group increased from 901 (+/-295) x 10(-3) to 1082 (+/-472) x 10(-3) (p<0.05). Only one patient showed a reduction in pulmonary artery pressure >20%, which is defined as significant vasodilatation. A strong relationship was found between the impedance changes and the change in PVR and mPAP in the patient with a significant vasodilatation on epoprostenol. From these results we conclude that EIT is a reliable method to measure blood volume changes due to pharmacologically induced vasodilatation in the pulmonary bed.

The prognostic role of the ECG in primary pulmonary hypertension

BACKGROUND/RATIONALE

Doppler echocardiography and invasive hemodynamic parameters reflective of right ventricular failure are associated with a poor prognosis in patients with primary pulmonary hypertension (PPH). The aims of the present study were to examine whether ECG features in patients with PPH are associated with a decrease in survival, and to determine the value of the ECG in risk stratification.

METHODS/RESULTS

We analyzed the ECG, New York Heart Association (NYHA) class, and hemodynamic parameters in 51 untreated patients with PPH (88% women; mean age, 41.7 years; 79% NYHA classes III and IV) evaluated between 1992 and 1998. Subsequent treatment included epoprostenol in 37 patients, calcium channel blockers in 10 patients, epoprostenol and atrial septostomy in 2 patients, and lung transplant in 3 patients. As of 1999, 16 patients had died. Based on Kaplan-Meier estimates, median survival was > 6.5 years and estimated survival at 1 year, 3 years, and 5 years was 86%, 71%, and 57%, respectively. Significant predictors of decreased survival by Cox regression analysis include pulmonary vascular resistance (PVR; hazard ratio [HR], 1.11 per Wood unit), cardiac index (HR, 0.22 per L/min/m(2)), p wave amplitude in lead II (HR, 3.06 per mm), p > or = 0.25 mV in lead II (HR, 2.77), qR in V(1) (HR, 3.55), and World Health Organization criteria for right ventricular hypertrophy (HR, 4.26). After controlling for PVR, the HRs attributable to the ECG criteria were only slightly diminished. NYHA class and pulmonary artery pressures did not correlate with a decrease in survival.

CONCLUSIONS

ECG parameters reflective of physiologic and anatomic abnormalities in the right ventricle are associated with decreased survival in patients with PPH, and may be useful for deciding therapeutic choices including the timing for lung transplantation listing.

Medical management of primary pulmonary hypertension

Primary pulmonary hypertension (PPH) is a rare disease effecting the pulmonary vasculature. Patients present with dyspnoea on exertion, chest pain, near syncope and evidence of right heart failure. The natural history of PPH was described in the 1980s and the survival rate was quite poor. The introduction of iv. epoprostenol in the early 1990s has significantly altered the natural history of this disease. Due to the complicated nature of this therapy, inhaled, sc. and oral prostacyclins have also been evaluated for treatment of PPH. The most recent class of medications added to the armamentarium for the treatment of PPH are the endothelin receptor antagonists. This paper reviews the available therapies for the treatment of PPH.

Severe pulmonary hypertension without right ventricular failure: the unique hearts of patients with Eisenmenger syndrome

Why adults with the Eisenmenger syndrome fare so much better than other patients with severe pulmonary hypertension is not known, but may be related to unique hemodynamics found only in these patients and in normal fetuses. We used echocardiography to evaluate ventricular morphology and function in 80 subjects: 45 cyanotic adults and 5 cyanotic adolescents with Eisenmenger syndrome, 10 infants with nonrestrictive ventricular septal defect and left-to-right shunt flow (pre-Eisenmenger phase), and 20 fetuses with structurally normal hearts. Cross-sectional morphology of the hearts was the same in all 4 groups with a flat ventricular septum throughout the cardiac cycle and equal thickness of the right and left ventricular free walls (regression slope 0.98, r = 0.97, p <0.0001). This morphology was the same in patients independent of age, defect type, and ventricular function. Right ventricular fractional area change was slightly inferior to that of the left ventricle but normal in most patients with Eisenmenger syndrome (0.47 +/- 0.14 vs 0.51 +/- 0.13, p <0.01). Overall, there was a highly significant linear relation between right and left ventricular function (r = 0.81, p <0.0001). The hearts of patients with Eisenmenger syndrome are more like normal fetal hearts than normal adult hearts. Because of the unique cardiovascular hemodynamics, regression of right ventricular wall thickness does not occur and is likely the reason that patients with Eisenmenger syndrome fare so much better than other adults with severe pulmonary hypertension.

Endothelin in health and disease: endothelin receptor antagonists in the management of pulmonary artery hypertension

Endothelin (ET) has been identified as playing a fundamental role in many disease processes. Therapeutic efforts at interrupting ET's pathologic effects have focused on endothelin receptor antagonists (ERAs), of which two, bosentan and sitaxsentan, have been evaluated for the treatment of both primary and secondary pulmonary arterial hypertension (PAH). We discuss the multiple actions of ET, its role in various disease states, and the effects of ET receptor stimulation and blockade. Current classification and management of PAH are reviewed, along with the promise of greatly improved treatment generated by recent and ongoing clinical trials using ERAs.

Clinical correlates and reference intervals for pulmonary artery systolic pressure among echocardiographically normal subjects

BACKGROUND

Data in normal human subjects on the factors affecting pulmonary artery systolic pressure (PASP) are limited. We determined the correlates of and established a reference range for PASP as determined by Doppler transthoracic echocardiography (TTE) from a clinical echocardiographic database of 102 818 patients, of whom 15 596 (15%) had a normal Doppler TTE study.

METHODS AND RESULTS

A normal TTE was based on normal cardiac structure and function during complete Doppler TTE studies. The PASP was calculated by use of the modified Bernoulli equation, with right atrial pressure assumed to be 10 mm Hg. Among TTE normal subjects, 3790 subjects (2432 women, 1358 men) from 1 to 89 years old had a measured PASP. The mean PASP was 28.3+/-4.9 mm Hg (range 15 to 57 mm Hg). PASP was independently associated with age, body mass index (BMI), male sex, left ventricular posterior wall thickness, and left ventricular ejection fraction (P<0.001). The estimated upper 95% limit for PASP among lower-risk subjects was 37.2 mm Hg. A PASP >40 mm Hg was found in 6% of those >50 years old and 5% of those with a BMI >30 kg/m(2).

CONCLUSIONS

Among 3790 echocardiographically normal subjects, PASP was associated with age, BMI, sex, wall thickness, and ejection fraction. Of these subjects, 28% had a PASP >30 mm Hg, and the expected upper limit of PASP may include 40 mm Hg in older or obese subjects. These findings support the use of age- and BMI-corrected values in establishing the expected normal range for PASP.

Lung and heart-lung transplant practice patterns in pulmonary hypertension centers

BACKGROUND

Transplant practice patterns for pulmonary hypertension in the epoprostenol era are unknown.

METHODS

Thirty-five centers in North America, Europe, and Israel were surveyed regarding practice patterns for lung and heart-lung transplant.

RESULTS

New York Heart Association class and distance on a 6-minute walk were considered most useful for deciding who to refer for listing. Patients with New York Heart Association class I to II were referred for listing in 26% of centers, while 57% were classified as New York Heart Association class III or greater after epoprostenol failure. Twenty-nine of the 35 centers had transplant programs that performed approximately 75% of the International Registry volume annually. A double lung transplant was preferred by 83% of centers and heart-lung transplant in the remaining centers. The wait time for lung transplant averaged 16.8 months (range 4-36) and for heart-lung transplant averaged 21.3 months (range 6-36) and was significantly longer in the United States. The mean maximum age for heart-lung transplant was 51.4 years (range 35-65), double lung transplant 58.3 years (range 45-65), and single lung transplant 63.1 years (range 50-70). Fifty-three percent of centers transplant New York Heart Association class III or IV patients, 26% class IIIb-IV, and 21% only class IV. Eighty percent of centers use a transplant hold status. Major unqualified exclusions were hepatitis in 38%, 1 or more hepatic (90%) or renal (100%) criteria, smoking 97%, and obesity in 93%.

CONCLUSIONS

Physicians and patients should be aware of the considerable variability in practice patterns for transplantation in pulmonary hypertension, despite published guidelines.