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

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.

Pulmonary artery remodeling differs in hypoxia- and monocrotaline-induced pulmonary hypertension

In the present study we analyzed structural characteristics of muscular pulmonary arteries and arterioles in two classic models of pulmonary hypertension, the rat hypoxia and monocrotaline models. We hypothesized that an increase in medial cross-sectional area would result in reduction of the lumen area and that these parameters would correlate with the increase in pulmonary artery pressure (PAP). Four weeks after a single injection of monocrotaline (MCT) or after 4 wk of hypoxic exposure the rats were killed. Both MCT and chronic hypoxia induced right ventricular hypertrophy. In separate groups of rats both MCT and chronic hypoxia increased PAP. MCT increased the media cross-sectional area of pulmonary arteries with an external diameter between 30-100 microm and 101-200 microm and reduced the lumen area of pulmonary arteries with an external diameter between 101-200 microm. Chronic hypoxia only slightly increased the media cross-sectional area without a change of the lumen area. Both MCT and hypoxia increased the percentage of partly muscularized and muscularized arterioles. The angiotensin-converting enzyme (ACE) inhibitor captopril (0.5 mg/kg/h) had no effect on MCT-induced pulmonary hypertension, right ventricular hypertrophy, and pulmonary artery remodeling. In chronic hypoxic rats it prevented an increase in medial cross-sectional area of pulmonary arteries with an external diameter between 30-100 microm and attenuated the increase in the percentage of muscularized arterioles, without any effect on the PAP. We conclude that MCT, in contrast to chronic hypoxia, induces structural changes of muscular pulmonary arteries with an external diameter between 101-200 microm which may contribute to an increased PAP and right ventricular hypertrophy. These data also suggest that angiotensin II plays a pivotal role in remodeling of pulmonary arteries in hypoxia but not in MCT-induced pulmonary hypertension.

Lung transplantation and repair of complex congenital heart lesions in patients with pulmonary hypertension

Pulmonary vascular disease in conjunction with either a previously repaired or an unrepaired congenital heart defect is the third most common indication for lung transplantation in the pediatric age range. Because scarcity of donor organs remains a critical issue and heart-lung donor blocks are becoming diminishingly available, efforts must be directed towards other options such as combining lung transplantation with correction of the underlying congenital heart defect. Certain defects like congenital pulmonary vein stenosis are eradicated by removal of the diseased lungs, whereas others such as complete atrioventricular canal and pulmonary atresia with ventricular septal defect require cardioplegic arrest of the heart and intracardiac repair in conjunction with the lung transplantation. A breakdown of this patient population into subgroups may be helpful both in thinking about the pathophysiology and in determining appropriate indications and timing of transplantation. Earlier studies from our center showed the high-risk nature and formidable undertaking of caring for this complex group of patients. Through continued experience, there has been gradual improvement in early outcomes. As with all other groups of lung transplantation patients, obliterative bronchiolitis remains the major deterrent to long-term survival.

The impact of bronchiolitis obliterans on late morbidity and mortality after single and bilateral lung transplantation for pulmonary hypertension

Primary pulmonary hypertension (PPH) is a rare cardiovascular disease with a variable course; however, in general, its prognosis is poor. Among the various treatment options available, transplantation (initially heart-lung transplantation, and later isolated single or bilateral lung transplantation) has become an accepted modality. Heart-lung transplantation is necessary only in a minority of patients because right ventricular recovery has been gratifying after isolated lung transplantation. Furthermore, the scarcity of suitable donor organs mandates the achievement of the maximal number of heart and lung transplants from the limited donor pool. Available published data show that both single and bilateral lung transplantation are suitable alternatives for the majority of patients with pulmonary hypertension. Bronchiolitis obliterans syndrome (BOS), the main cause of late mortality and morbidity in lung transplant recipients, affects pulmonary hypertensive patients as it does other recipient subgroups. The available data regarding the impact of BOS on single versus bilateral lung recipients with pulmonary hypertension are somewhat scanty. Although some have suggested that BOS is more prevalent among PPH recipients, this is not uniformly supported through the literature. Other reports have documented severe ventilation-perfusion imbalance associated with graft dysfunction secondary to BOS in single lung transplant recipients with PPH. Despite this, there are no available data to document a significant survival benefit for PPH patients receiving bilateral versus single lung transplantation. Our own transplantation experience at Washington University in St. Louis with pulmonary hypertension shows a trend toward better survival in bilateral lung recipients, although this difference is not significant. Ultimately, both single and bilateral lung replacement seem to be satisfactory transplant options in PPH. Both recipient groups are affected by BOS, and longer follow-up of larger numbers of patients may document superior survival and functional outcome with bilateral lung replacement.

Lung transplantation for pulmonary hypertension: patient selection and maintenance therapy while awaiting transplantation

Although lung transplantation is considered a definitive treatment of patients with advanced pulmonary vascular disease and pulmonary hypertension, advances in the success of the medical management of patients with pulmonary hypertension make it less clear as to when to refer a patient for transplantation. Coumadin anticoagulation is associated with improved survival in all patients, and calcium channel blockers therapy with improved survival in very select patients. Chronic prostacyclin represents a newer therapy that seems to have a dramatic impact on patients' functional class and survival. As improvements continue in the medical management in pulmonary hypertension, and in survival of patients undergoing lung transplantation, the guidelines for patient selection should be constantly evolving.

Ethical issues in lung transplantation

Lung transplantation is now an accepted therapeutic option for many patients with incurable end-stage lung or pulmonary vascular disease processes for which other treatment options have been expended. However, as lung transplantation has evolved as a recognized discipline over the past decade, a variety of ethical issues related to the transplant process are emerging. This article considers those issues through a discussion of the four fundamental principles of biomedical ethics.

Medical and surgical treatment options for pulmonary hypertension

Significant advances in the treatment of pulmonary hypertension have been achieved in the past decade. Approximately one quarter of patients with primary pulmonary hypertension (PPH) can be effectively managed with chronic calcium channel blocker therapy; for the remainder, transplantation or continuous intravenous epoprostenol are complex but effective approaches. Epoprostenol therapy was initially envisioned as a bridge to transplantation, but recent experience has established this approach as an alternative to transplantation in some patients, with comparable survival rates. Not all patients derive benefit from epoprostenol, however, and adverse effects are common. Accordingly, patients who fall into New York Heart Association Functional Classes III and IV and who are refractory to oral vasodilator therapy should be evaluated both for the initiation of epoprostenol therapy and concurrent listing for transplantation. By delaying or avoiding transplantation through the use of epoprostenol, these patients may also benefit from ongoing research that targets novel therapeutic approaches and less cumbersome delivery mechanisms. Thus, epoprostenol may serve as a bridge to transplantation for some patients and to newer therapeutic options for others.

Right and left ventricular dysfunction in patients with severe pulmonary disease

OBJECTIVE

To determine the prevalence of right and left ventricular dysfunction in a prescreened population of patients with severe pulmonary disease, and to analyze the relationship between right and left ventricular function.

DESIGN

Retrospective record review of 434 patients with severe pulmonary disease.

PATIENTS

Patients with end-stage pulmonary disease, including alpha1-antitrypsin deficiency emphysema, COPD, cystic fibrosis (CF), idiopathic pulmonary fibrosis, and pulmonary hypertension (primary and Eisenmenger's syndrome), who were evaluated for lung transplantation between January 1993 and December 1995.

MEASUREMENTS

Pulmonary function tests, arterial blood gases, radionuclide ventriculography, two-dimensional transthoracic echocardiography, pulmonary hemodynamics, coronary angiography.

RESULTS

Right ventricular dysfunction (right ventricular ejection fraction [RVEF] <45%) was present in 267 patients (66%), but the prevalence was highest (94%) in patients with pulmonary vascular disease. Among the patients with airway or parenchymal lung disease, the prevalence ranged from 59% in COPD to 66% in CF. In contrast, left ventricular dysfunction (left ventricular ejection fraction [LVEF] <45%) was present in only 6.4%, but it, too, was most common in the group with pulmonary hypertension (19.6%). In the groups with parenchymal or airway disease, the prevalence was 3.6%, and there was no statistical difference among the four diagnoses (alpha1-antitrypsin deficiency emphysema; COPD; CF; idiopathic pulmonary fibrosis). LVEF showed a significant correlation with RVEF (r=0.44; p<0.05), and left ventricular dysfunction was associated with the presence of moderate-to-severe tricuspid regurgitation but not with coronary artery disease. In a subset of patients with both right and left ventricular dysfunction who subsequently underwent lung transplantation, RVEF and LVEF increased pari passu after transplantation.

CONCLUSION

The prevalence of right ventricular dysfunction is high in patients with end-stage pulmonary disease, but the prevalence of left ventricular dysfunction is relatively low. Left ventricular dysfunction appears to be related to right ventricular dysfunction, perhaps through ventricular interdependence.

Beneficial hemodynamic effects of oral prostacyclin (PGI2) analogue, beraprost sodium, on a patient with primary pulmonary hypertension--a case report

A 65-year-old woman was admitted to our hospital because of exertional dyspnea in 1987. A diagnosis of primary pulmonary hypertension was confirmed by right heart catheterization. She had received conventional therapy in the outpatient clinic. She was readmitted with the deterioration of exertional dyspnea in 1995. Stabilization of pulmonary hemodynamics, while not achieved with conventional therapy, was achieved with additive administration of an oral prostacyclin (PGI2) analogue, beraprost sodium.

Treatment of pulmonary hypertension with the continuous infusion of a prostacyclin analogue, iloprost

OBJECTIVE

To compare prostacyclin with an analogue, iloprost, in treatment of severe pulmonary hypertension.

PATIENTS

Eight patients with severe pulmonary hypertension: primary in five, thromboembolic pulmonary hypertension in three.

METHODS

All patients underwent right heart catheterisation. Mean (SEM) right atrial pressure was 9.9 (2.2) mm Hg, mean pulmonary artery pressure 67.4 (3.0) mm Hg, cardiac index 1.75 (0.13) l/min/m2 and mixed venous oxygen saturation 59.1(3.1)%. Continuous intravenous epoprostenol (prostacyclin, PGI2) or iloprost was given for phase I (three to six weeks); the patients were then crossed over to receive the alternate drug in an equivalent phase II.

MAIN OUTCOME MEASURES

Exercise tolerance was measured at baseline and at the end of phase I and II with a 12 minute walk; distance covered, rest period, percentage drop in arterial oxygen saturation (delta Sao2%) and percentage rise in heart rate (delta HR%).

RESULTS

Walking distance covered rose from (mean (SEM)) 407.5 (73) to 591 (46) m with PGI2 (p = 0.004) and to 602.5 (60) m while on iloprost (p = 0.008). Rest period decreased from 192 (73) seconds at baseline to 16 (16) seconds with PGI2 (p = 0.01) and to 58 (34) seconds with iloprost (p = 0.008). Delta HR% was 37.5(6)% at baseline, 35(3)% on PGI2, and 24(6)% on iloprost (p = 0.04).

CONCLUSIONS

Both intravenous PGI2 and iloprost caused significant improvement in exercise tolerance. Iloprost offers an alternative to PGI2 treatment of severe pulmonary hypertension.

Rapid recurrence of pulmonary hypertension following cessation of nifedipine

In a young woman with primary pulmonary hypertension, treatment with low-dose nifedipine resulted in resolution of symptoms and of tricuspid regurgitation. On withdrawal of nifedipine, symptomatic pulmonary hypertension recurred within 48 hours and was controlled by reintroduction of low-dose nifedipine.

Human immunodeficiency virus infection and pulmonary hypertension: two new cases and a review of 86 reported cases

In this article, we describe pulmonary hypertension in two men (31 and 43 years of age) with human immunodeficiency virus (HIV) infection who were examined at Mayo Clinic Rochester. Among 88 reported cases (including the two current ones) of HIV- or acquired immunodeficiency syndrome (AIDS)-associated pulmonary hypertension, 61% were male; the age range was 2 to 56 years (mean, 32). Dyspnea was the usual initial symptom. Of the 74 patients in whom pulmonary artery pressure was recorded or calculated by echocardiography, systolic pressures ranged from 49 to 118 mm Hg (mean, 68). Of the 33 cases in which lung tissue was evaluated microscopically, 28 (85%) were of the plexogenic variant of pulmonary arterial hypertension. Of the other five cases examined histologically, three consisted of thrombotic pulmonary arteriopathy (one was due to recurrent thromboembolism, and the other two were due to in situ thrombosis), and two were of pulmonary venoocclusive disease. No correlation existed between either CD4 counts or a history of pulmonary infections and the development of pulmonary hypertension. In 15 of the 88 patients (17%), confounding factors for hypertensive pulmonary vascular disease were present, including coexisting liver disease in 13 and coagulation abnormalities in 2. In 83% of the patients, the development of pulmonary hypertension seems to have been related primarily to the chronic HIV infection. Pulmonary hypertension was more rapidly progressive in patients with HIV or AIDS than in those with primary pulmonary hypertension; the reported time intervals between onset of symptoms and diagnosis were 6 months and 30 months, respectively. The 1-year survival rate for patients with HIV and pulmonary hypertension was 51%, based on the follow-up data compiled from the 63 patients in whom it was described; this compares with a 1-year survival rate of 68% for patients with primary pulmonary hypertension. Death was considered a direct consequence of pulmonary hypertension in 29 (76%) of the 38 fatal cases.

Gaucher's disease: clinical features and natural history

Gaucher's disease is an inherited disorder characterized by pathological storage of glycolipid in mononuclear phagocytes: it is a multi-system disease associated with striking variation in its clinical manifestations, severity and course. Although molecular analysis of the glucocerebrosidase gene in patients with Gaucher's disease has permitted broad correlations between genotype and phenotype to be made, with few exceptions genetic variation at this locus does not allow confident prediction of clinical phenotype or prognosis. Partial deficiency of glucocerebrosidase is associated principally with parenchymal disease of the liver, spleen, bone marrow and, in severe cases, the lung, in non-neuronopathic, Type 1, Gaucher's disease: here storage material in macrophages originates from turnover of exogenous glycolipids. Severe deficiency of glucocerebrosidase caused by disabling mutations is additionally associated with neurological manifestations that in part reflect a failure to degrade endogenous neuronal glycosphingolipids, the so-called neuronopathic, Type 2 and Type 3 disease categories. Here we describe the clinical features, complications and natural history principally of Type 1 Gaucher's disease: emphasis is placed on emerging pulmonary, osseous and other manifestations of obscure pathogenesis that respond poorly to enzyme-replacement therapy.

Successful blade atrial septostomy in a patient with severe primary pulmonary hypertension--a case report

Blade atrial septostomy (BAS) for pulmonary hypertension has increased long-term survival and is an effective and palliative preliminary to heart and/or lung transplantation. We treated an 18-year-old woman with severe pulmonary primary hypertension whose symptoms had worsened as a resulted low cardiac output. The patient's right ventricular pressure was 150/23 mmHg, cardiac index (CI) 1.0 L/min per m2, and she showed signs and symptoms of severe primary pulmonary hypertension. We performed BAS successfully, paying particular attention to the following points. To maintain pulmonary blood flow after creating an atrial right-to-left shunt, the patient was infused intravenously with packed red blood cells and volume expander. Oxygen delivery was also increased by the transfusion of packed red blood cells. To avoid unacceptable hypoxemia immediately after the procedure, the atrial septum was initially incised with a very small-blade catheter. Nine months after the BAS, catheterization revealed a decrease in mean pulmonary arterial pressure to 73 mmHg and an increase in CI to 2.5 L/min per m2. Thirteen months after the BAS, the patient died as a result of progressive worsening of right-sided heart failure. We concluded that BAS could be successful in patients with severe pulmonary hypertension providing attention is paid to the patient's condition and that BAS is an effective therapy for prolonging survival.

Epidemiology of advanced lung disease in the United States

ALD affects a large segment of the population in the United States, both old and young, and men and women of all races and ethnicities. Many chronic diseases inevitably advance to a stage that results in significant respiratory impairment and disability. Although the causes of some of the diseases are known and the diseases may be preventable, the overall absolute burden of illness in the population is rising because of an enlarging population and newer therapeutic approaches. This is evident despite the lack of consistent and comparable data estimates for all diseases from national database resources. Where the data exist, it is evident that the cost related to the morbidity and mortality of these illnesses is substantial and consumes a significant proportion of health care expenditures. Both morbidity and mortality estimates, as well as cost estimates, are conservative and are likely underestimates of the true overall impact of ALD on the US economy.

Natural history and prognosis of advanced lung disease

Large gaps exist in our knowledge of the natural history of advanced lung disease and of the impact of various therapies upon prognosis and survival. Applying the results of population-based epidemiologic studies or limited clinical trials to a specific patient is hazardous because of marked individual variation in survival, even with the most grim of prognoses. Obtaining such prognostic information is essential, however, in addressing current key issues in advanced lung disease-the efficacy of various therapies, timing lung transplantation, referring to hospice care, providing palliative therapy, and determining medical futility.

Lung transplantation. A disease-specific approach

Lung transplantation has emerged as a viable option for the treatment of end-stage disease attributable to a wide spectrum of primary disorders. Although many aspects of patient management are indifferent to the underlying indication, important differences related to timing of transplantation, selection of candidates, choice of procedure, and post-transplant complications exist among the various primary disease groups. Optimal utilization of transplantation for these challenging patient populations with advanced lung disease mandates a thorough appreciation of those differences.

Left main coronary artery compression during primary pulmonary hypertension

Primary pulmonary hypertension (PPH) is often associated with angina-like chest pain, the mechanism of which is controversial. A 37-year-old woman with severe PPH and angina had transient ischemic ECG changes and reversible anterior perfusion defect on 201thallium scintigraphy. Coronary angiography revealed severe stenosis of the left main coronary artery (LMCA) and otherwise normal vessels. After heart-lung transplantation, examination of the explanted heart showed normal coronary arteries. Compression of the LMCA by the dilated pulmonary artery trunk was responsible for myocardial ischemia. This mechanism should be considered in patients with PPH and angina and might contribute to the high sudden death rate.

Hemodynamic data and survival in children with pulmonary hypertension

OBJECTIVES

Using data from a multi-institutional data base, we sought to determine whether hemodynamic data predict duration of survival in children with primary or secondary pulmonary hypertension.

BACKGROUND

Lung transplantation is a therapeutic option for children with pulmonary hypertension. Appropriate timing of lung transplantation requires reliable methods of predicting duration of survival in potential candidates.

METHODS

A regional data base was used to obtain cardiac catheterization data on 50 children with mean pulmonary artery pressure (mPAP) > 25 mm Hg and indexed pulmonary resistance (Rp) > 4.5 Wood units. Data on survival were obtained from the participating centers.

RESULTS

There were 15 patients without congenital heart disease (group 1) and 35 patients with congenital heart disease (group 2) for analysis. Actuarial survival at 1, 2 and 5 years was 86%, 69% and 69% in group 1 and 88% and 77% in group 2, respectively (p = NS). Hemodynamic variables that predicted survival on univariate analysis were mean right atrial pressure (mRAP) (p < 0.0001), mPAP (p = 0.034), Rp (p < 0.0001) and pulmonary flow (p = 0.003), as well as a variable that we generated-mRAP x Rp (p < 0.0001). On multivariate stepwise logistic regression analysis, mRAP x Rp was independently related to survival. A model using mRAP x Rp allows for the estimation of probability of death at 1 and 2 years after catheterization.

CONCLUSIONS

Hemodynamic variables can predict survival in children with pulmonary hypertension in the presence or absence of congenital heart defects. This information can be used to determine the optimal timing of listing for lung transplantation.

Comparison of bronchopulmonary collaterals and collateral blood flow in patients with chronic thromboembolic and primary pulmonary hypertension

OBJECTIVE

To compare the visualisation of bronchopulmonary collaterals and bronchopulmonary collateral blood flow in patients with chronic thromboembolic pulmonary hypertension 2nd primary pulmonary hypertension.

SETTING

Referral centre for cardiology at an academic hospital.

PATIENTS

Nine patients with chronic thromboembolic pulmonary hypertension and 17 with primary pulmonary hypertension.

INTERVENTIONS

Bronchopulmonary collaterals were visualised by selective bronchial arteriography or thoracic aortography. Bronchopulmonary collateral blood flow was estimated by injecting indocyanine green into the ascending aorta and sampling below the mitral valve from the left ventricle.

RESULTS

The degree of pulmonary hypertension was comparable in the two groups. Large bronchopulmonary collaterals were visualised in all the patients with thromboembolic pulmonary hypertension who had bronchial arteriography or aortography or both. None of the primary pulmonary hypertension group studied by aortography had bronchopulmonary collaterals (P < < 0.001). All the patients with chronic thromboembolic pulmonary hypertension had significant bronchopulmonary collateral blood flow, which was (mean (SD)) 29.8 (18.6)% of the systemic blood flow. There was no recordable collateral blood flow in 11 of 15 patients with primary pulmonary hypertension. In the remaining four patients the mean value was 1.1 (1.8)% of the systemic blood flow (P < < 0.001).

CONCLUSIONS

Visualisation of bronchopulmonary collaterals by thoracic aortography or by bronchial arteriography, or the demonstration of an increased bronchopulmonary collateral flow, helps to distinguish patients with chronic thromboembolic pulmonary hypertension from those with primary pulmonary hypertension.

Primary pulmonary hypertension: improved long-term effects and survival with continuous intravenous epoprostenol infusion

OBJECTIVES

This study sought to determine the long-term effects of continuous infusion of epoprostenol (epo) therapy on survival and pulmonary artery pressure in patients with primary pulmonary hypertension (PPH).

BACKGROUND

PPH is a progressive disease for which there are few effective therapies.

METHODS

Patients with PPH and New York Heart Association functional class III or IV symptoms of congestive heart failure underwent right heart catheterization and Doppler-echocardiography to measure the maximal systolic pressure gradient between the right ventricle and right atrium (delta P) and cardiac output (CO). Doppler-echocardiography and catheterization data were compared. Patients were followed up long term with Doppler-echocardiography.

RESULTS

Of 69 patients who went on to receive epo, 18 were followed up for > 330 days (range 330 to 700). During long-term follow-up, there was a significant reduction in delta P, which decreased from 84.1 +/- 24.1 to 62.7 +/- 18.2 (mean +/- SD, p < 0.01). A Kaplan-Meier plot of survival of our study patients demonstrated improved survival compared with that of historical control subjects. The 1-, 2- and 3-year survival rates for our patients were 80% (n = 36), 76% (n = 22) and 49% (n = 6) compared with 10- (88%, n = 31), 20- (56%, n = 27) and 30-month (47%, n = 17) survival rates in historical control subjects.

CONCLUSIONS

Patients receiving continuous infusion of epo for treatment of PPH experience a decrease in pulmonary artery pressure. Long-term follow-up of this single-center patient group demonstrated improved long-term survival during epo therapy compared with that in historical control subjects and confirms predicted improved outcomes based on shorter follow-up periods.

Primary pulmonary hypertension in a patient with CD8/T-cell large granulocyte leukemia: amelioration by cladribine therapy

We report a case of primary pulmonary hypertension in an adult man with CD8/T-cell large granulocyte leukemia. Successful treatment of his leukemia with cladribine resulted in dramatic and sustained improvement of his pulmonary hypertension.

Usefulness of atrial septostomy as a treatment for primary pulmonary hypertension and guidelines for its application

We review our experience and that for 2 large series of atrial septostomy as a treatment for advanced pulmonary hypertension to better understand the hemodynamic changes that result. Atrial septostomy may be a useful procedure in patients with severe refractory pulmonary hypertension, but should not be used in patients who are critically ill.

Patient selection, evaluation, and preoperative management for lung transplant candidates

The selection process to assess candidacy for transplant is based on medical and psychosocial criteria and surgical considerations. The degree of disease severity requiring transplantation for survival has become more apparent as the disparity in survival outcome widens between patients with and without transplant. The contraindications to transplant surgery have been modified over time. Candidate selection is considered in the context of the risks and benefits of the surgical procedure on a case by case basis. The wait for transplant has increased as the growth in the number of candidates for transplant exceeds available donors. As much as 30% of patients die on the UNOS waiting list.

Pulmonary hypertension in systemic autoimmune disease

Rare in occurrence, insidious in onset, and relentless in its course, pulmonary hypertension in systemic autoimmune disease remains one of the most challenging entities to diagnose and treat today. The subtlety and nonspecificity of its symptoms and signs, the lack of availability of sensitive, noninvasive, accurate diagnostic tests, the rudimentary understanding we have of its pathogenesis, the multiplicity of findings on histopathologic survey, and the paucity of data from large-scale therapeutic trials in this population all pose many frustrations for patient and physician. Although supportive, symptomatic therapy remains the mainstay of treatment, we continue to await the results of carefully conducted clinical trials investigating antiinflammatory drugs and vasodilators. Careful scrutiny of the histologic lesions seen in pulmonary hypertension has shown striking similarity with the changes of PPH in some patients, and close follow-up of patients diagnosed with PPH has shown that some of them later develop evidence of a specific autoimmune disease like scleroderma. A natural tendency to extrapolate the use of therapeutic modalities of PPH to patients with autoimmune disease-associated pulmonary hypertension then results. We are thus encouraged by the lessons learned from the past about PPH; studies of patients with PPH have identified a subset of them who enjoy a distinct survival advantage with use of vasodilators or transplantation. We remain hopeful that future investigations in the treatment of autoimmune disease-associated pulmonary hypertension will yield similar information, and that we will be able to provide afflicted individuals some long-awaited improvements in quality and duration of life.

Treatment of primary pulmonary hypertension with continuous intravenous prostacyclin

Our ultimate goal in treating patients is to improve their quality of life and to increase survival. The optimal treatment for primary pulmonary hypertension will continue to change as our understanding of its causes improves and as progress is made in lung transplantation. There is no one best treatment for all patients. Optimal medical and surgical treatment must be tailored to the individual with changes in therapeutic regimens based on serial evaluations. Quality of life and survival have improved with current treatments and the future should offer additional therapies-inhaled nitric oxide, endothelin receptor blockers, and other modulators of the pulmonary vascular bed-to improve further the treatment of this disease. In conclusion, although primary pulmonary hypertension, if untreated, is most often a rapidly progressive and fatal disease, recent advances in the treatment have significantly improved the outcome for patients. Although transplantation is often considered the only definitive treatment for patients with primary pulmonary hypertension, medical treatment seems to be an effective long term palliation to successful transplantation as well as a possible alternative treatment to transplantation in selected children and adults. Quality of life and cost analyses, as well as longer follow up studies are needed to determine the best treatment for patients with primary pulmonary hypertension.

Effects of long-term infusion of prostacyclin (epoprostenol) on echocardiographic measures of right ventricular structure and function in primary pulmonary hypertension. Primary Pulmonary Hypertension Study Group

BACKGROUND

Right heart failure is an important cause of morbidity and mortality in primary pulmonary hypertension. In a recent prospective, randomized study of severely symptomatic patients, treatment with prostacyclin (epoprostenol) produced improvements in hemodynamics, quality of life, and survival. This article describes the echocardiographic characteristics of participants in this trial; the relationship of echocardiographic variables to hemodynamic parameters, exercise capacity, and quality of life; and the echocardiographic changes associated with prostacyclin therapy.

METHODS AND RESULTS

The 81 patients enrolled in this multicenter trial were randomized to treatment with a long-term infusion of prostacyclin in addition to conventional therapy (n = 41) or conventional therapy alone (n = 40) for 12 weeks. Echocardiograms and assessments of hemodynamics, exercise capacity, and quality of life were performed before and after the treatment phase. On baseline evaluation, patients had marked right ventricular dilatation and dysfunction, abnormal septal curvature, and significant tricuspid regurgitation with a high regurgitant velocity. Pericardial effusions were common. More pronounced abnormalities in right heart structure and function were associated with higher pulmonary arterial and mean right atrial pressures, lower cardiac index, and impaired exercise capacity but had no predictable relationship to quality-of-life indicators. The 12-week infusion of prostacyclin had beneficial effects on right ventricular size, curvature of the interventricular septum, and maximal tricuspid regurgitant jet velocity.

CONCLUSIONS

The echocardiographic manifestations of severe primary pulmonary hypertension reflect abnormalities in hemodynamics and exercise capacity. Prostacyclin has beneficial effects on right heart structure and function that may contribute to the clinical improvement and prolonged survival observed with this drug.

Localization of the gene for familial primary pulmonary hypertension to chromosome 2q31-32

Primary pulmonary hypertension (PPH), an often fatal disease, is characterized by elevated pulmonary artery pressures in the absence of a secondary cause. Endovascular occlusion in the smallest pulmonary arteries occurs by proliferation of cells and matrix, with thrombus and vasospasm. Diagnosis is often delayed because the initial symptoms of fatigue and dyspnea on exertion are nonspecific and definitive diagnosis requires invasive procedures. The average life expectancy after diagnosis is two to three years with death usually due to progressive right heart failure. The aetiology of the disease is unknown. Although most cases appear to be sporadic, approximately 6% of cases recorded in the NIH Primary Pulmonary Hypertension Registry are inherited in an autosomal dominant manner with reduced penetrance. Following a genome-wide search using a set of highly polymorphic short tandem repeat (STR) markers and 19 affected individuals from six families, initial evidence for linkage was obtained with two chromosome 2q markers. We subsequently genotyped patients and all available family members for 19 additional markers spanning approximately 40 centiMorgans (cM) on the long arm of chromosome 2. We obtained a maximum two-point lod score of 6.97 at theta = 0 with the marker D2S389; multipoint linkage analysis yielded a maximum lod score of 7.86 with the marker D2S311. Haplotype analysis established a minimum candidate interval of approximately 25 cM.

Lung transplantation: selection of patients and analysis of outcome

Lung transplantation is an important option for patients with respiratory failure and limited life expectancy. Herein we review the current indications for and outcome after lung transplantation. These results are compared with the natural history of various respiratory diseases, estimated from available databases. Candidates for lung transplantation are generally younger than 60 years of age, have a limited life expectancy because of end-stage lung disease, and have no other major organ dysfunction. Single lung transplantation is performed most commonly for emphysema, pulmonary fibrosis, and pulmonary hypertension. Survival after single lung transplantation is approximately 70% at 1 year, 60% at 2 years, and 40% at 3 years. The median duration of survival for patients with end-stage lung diseases ranges from approximately 2 to 6 years, with wide variation based on the diagnosis and severity of illness. Currently, prolongation of the average survival has not been clearly substantiated after lung transplantation. Further evaluation of outcomes, functional status, and quality of life after lung transplantation is necessary.

Clinical trials in pulmonary hypertension

Progress in treatment of pulmonary hypertension has been impaired by the lack of formal clinical trials. This is now beginning to change, and the impact on our approach to treating patients with pulmonary hypertension in substantial. As with other relatively uncommon medical disorders, randomized, controlled, multi-center trials are needed to assess the safety and efficacy of potential therapeutic modalities. Treatments showing promise at the level of small pilot studies within a single center should be studied more rigorously.

Outcome of children with pulmonary hypertension referred for lung or heart and lung transplantation

We reviewed our institutional experience with 24 children with pulmonary hypertension, who were referred for lung or heart and lung transplantation. Diagnosis, age, and previously published predictive survival scores calculated at the time of referral were analyzed as predictors of pretransplant death. Among the 24 children, 7 did not meet criteria for listing and 17 were listed for transplantation. Of those listed, eight died waiting, two await transplantation, and seven were transplanted and are alive and well 7-20 months after transplantation. Poor functional status (New York Heart Association class 3 or 4) at the time of referral was significantly associated with death before transplant (P=0.05) in univariate analysis. Analysis of the predictive scores was possible in 21 of 24 patients; lower predictive scores were significantly associated with death before transplantation and shorter duration of survival without transplantation in univariate analysis. Multivariate analysis (Cox regression) confirmed that lower scores were significantly associated with poor survival. We conclude that children with pulmonary hypertension are often referred for transplantation too late in the course of their disease. Early complete hemodynamic evaluation before the onset of severe symptoms, followed by serial evaluations of disease progression and consultation with a transplant center, should result in earlier, more appropriate time of listing and improved survival. A systematic study of pretransplant mortality among all children listed for lung transplantation would provide a basis for clinical decision making and policies affecting organ allocation.

Systemic fat embolism and pulmonary hypertension in sickle cell disease

Systemic fat embolism, a relatively rare complication of sickle cell disease, is difficult to diagnose and it is often fatal. A high index of suspicion and early transfusion therapy may provide the best chance for recovery. Sickle cell-related pulmonary hypertension can be documented by cardiac catheterization but has no proven treatment. Patients with this complication are usually adults, have a poor prognosis, and may be considered for hydroxyurea treatment. Administration of vasodilators, anticoagulation, or oxygen may be beneficial in selected individuals.

Re-examining the clinical safety and roles of calcium antagonists in cardiovascular medicine

Despite recent analyses questioning the safety of calcium antagonists, evidence and clinical practice strongly support a major role for these drugs in the management of many cardiovascular diseases such as arrhythmia, vascular spasm, hypertension, diastolic dysfunction, stable angina, and myocardial infarction. These agents are a heterogeneous class of drugs with each formulation possessing unique properties and clinical applications. This article presents a review of the available literature and discusses the recommended use of various calcium antagonists in the treatment of diseases of the heart and vascular system.

Coagulation and fibrinolytic profiles in patients with severe pulmonary hypertension

STUDY OBJECTIVES

Although in situ thrombosis is a prominent finding in lung vessels from patients with primary and secondary pulmonary hypertension, to our knowledge, plasma coagulation factors that might contribute to a hypercoagulable state have not been fully investigated. We hypothesized that the local coagulation environment in the lung vasculature is important to progression if not initiation of pulmonary hypertension.

DESIGN

Quasi-experimental cross-sectional design with concurrent controls.

SETTING

Referral clinics and inpatient services of a University Hospital and a Veterans Administration Medical Center.

PARTICIPANTS

To investigate the role of plasma coagulation factors in severe pulmonary hypertension, we sampled plasma from patients with primary pulmonary hypertension, patients with pulmonary hypertension secondary to a discernible etiology, and normal adult control subjects.

RESULTS

We detected abnormalities of the thrombomodulin/protein C anticoagulant system, evidenced by a decrease in soluble thrombomodulin, in patients with primary pulmonary hypertension. In the patients with primary pulmonary hypertension, we found impaired fibrinolytic activity, with a rise in the fibrinolytic inhibitor plasminogen activator 1 and elevated euglobulin lysis time. Lower fibrinolytic activity correlated with high mean pulmonary artery pressure. In contrast, in patients with secondary pulmonary hypertension, von Willebrand factor antigen and fibrinogen levels were increased, and fibrinolytic activity decreased.

CONCLUSIONS

Different patterns of coagulation and fibrinolytic abnormalities are apparent in plasma from patients with primary and secondary pulmonary hypertension. Although we are unable to address causality with this study, we speculate that abnormalities of these coagulation mechanisms may initiate or play a role in perpetuation of pulmonary hypertension.

Right ventricular pathology in chronic pulmonary hypertension

Right ventricular free wall biopsy specimens in 40 patients undergoing surgery for relief of chronic thromboembolic pulmonary hypertension were normal in 5%, disclosed only myocyte hypertrophy in 80%, mild focal fibrosis in 12.5%, and myocarditis in 2.5%. There was no relation between postsurgical functional or hemodynamic outcomes and the presence of focal fibrosis.

Primary pulmonary hypertension as a risk factor for the development of obliterative bronchiolitis in lung allograft recipients

STUDY OBJECTIVES

Obliterative bronchiolitis (OB) is a major factor limiting long-term survival after lung transplantation. The etiology of this disease process remains incompletely understood. Several risk factors have been identified previously, including acute rejection and cytomegalovirus pneumonitis. The purpose of this study was to evaluate primary pulmonary hypertension (PPH) as a potential risk factor for the development of OB after lung transplantation.

DESIGN AND PATIENTS

We retrospectively analyzed 107 lung allograft recipients (28 heart-lung, 18 bilateral sequential single-lung, 61 single-lung) who underwent transplantation between May 1, 1986, and April 30, 1994, and survived at least 3 months posttransplant. Mean follow-up posttransplant was 28.6 months (range, 3.5 to 99 months). Actuarial survival was estimated for patients with or without PPH and for those who did or did not develop OB.

RESULTS

In all, 25 patients (23.4%) developed OB, diagnosed by strict histologic criteria. Of 23 patients with PPH, 9 (39.1%) developed OB, compared with 16 (19.0%) of 84 patients without PPH (p = 0.044). Actuarial survival, sex, time on waiting list, and follow-up posttransplant were not significantly different between groups. PPH was the major determinant for the development of OB (p = 0.0468) when evaluating PPH and cytomegalovirus pneumonitis together as risk factors. Patients with PPH also developed OB significantly earlier posttransplant, compared with patients with other primary disease (p = 0.05).

CONCLUSIONS

Patients with PPH who undergo lung transplantation are at increased risk for the development of OB, which also occurs at a shorter time interval posttransplant. This subgroup needs aggressive monitoring for diagnosis and treatment of OB.

Improvement of severe pulmonary hypertension in a patient with SLE

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Reduction of pulmonary capillary blood volume in patients with severe unexplained pulmonary hypertension

BACKGROUND

Unexplained or primary pulmonary hypertension results in an obliteration and obstruction of resistance pulmonary arteries. In these patients gas exchange is impaired and the measurement of gas transfer for carbon monoxide is usually reduced. This has been thought to represent a reduction in pulmonary alveolar capillary blood volume (Vc). A single breath test, measuring simultaneously the uptake of both nitric oxide (NO) and carbon monoxide (CO), provides a simple and practical measurement of membrane diffusion (Dm) and Vc.

METHODS

A standard single breath test for the measurement of gas transfer for carbon monoxide (TLCO) was adapted to include NO (40 ppm) in the inhaled gas mixture and a breath-hold time at total lung capacity of 7.5 seconds was used. Twelve patients with primary pulmonary hypertension and 10 similar normal volunteers were studied while seated at rest.

RESULTS

The patients had reduced values for TLCO and TLNO. The mean (SD) value of Dm in the patients was 36.7 (32.1) mmol/min.kPa compared with 52.8 (23.9) mmol/min.kPa in the normal subjects. Vc in the patients was 0.03 (0.03) 1 and 0.06 (0.01) 1 in the normal subjects.

CONCLUSIONS

The simultaneous measurement of NO and CO uptake is possible in healthy volunteers and patients with primary hypertension. In these patients capillary blood volume is reduced compared with normal subjects.