Primary pulmonary hypertension in children: clinical characterization and survival

Electrocardiography in the diagnosis of right ventricular hypertrophy in children

OBJECTIVE

Although the electrocardiogram is commonly obtained in the evaluation of patients with pulmonary hypertension, its value as a screening test for right ventricular hypertrophy or pulmonary hypertension is unclear. Therefore, we sought to determine the value of an electrocardiogram in the diagnosis of right ventricular hypertrophy using echocardiography as the gold standard.

METHODS

We identified children without congenital heart disease who underwent evaluation for suspected pulmonary hypertension that included both an electrocardiogram and echocardiography within a specified time frame.

RESULTS

A total of 76 echocardiography-electrocardiogram pairs for pulmonary hypertension were identified. Although there was a significant relationship between electrocardiogram and echocardiography evidence of right ventricular hypertrophy, the sensitivity of an electrocardiogram in diagnosing echocardiography-documented right ventricular hypertrophy was only 69%, and the positive predictive value was 67%. There was no relationship between electrocardiogram changes and Doppler tricuspid regurgitation gradient.

CONCLUSION

Despite a statistically significant relationship between an electrocardiogram and echocardiography in the diagnosis of right ventricular hypertrophy, an electrocardiogram has limited value as a screening tool for right ventricular hypertrophy because of its relatively low sensitivity and positive predictive value.

Use of myocardial performance index in pediatric patients with idiopathic pulmonary arterial hypertension

BACKGROUND

The myocardial performance index (MPI) correlates with clinical status in adults with idiopathic pulmonary arterial (PA) hypertension (IPAH). This pediatric study used MPI to assess response to bosentan therapy.

METHODS

The study included 12 children with IPAH and 12 healthy control subjects. MPI was correlated with catheterization data at initiation of bosentan and at a median follow-up of 9 months. Therapy responders were defined by a greater than 20% decrease in mean PA pressure.

RESULTS

Right ventricular MPI for patients with IPAH was 0.64 +/- 0.30 versus 0.28 +/- 0.03 in control subjects (P < .01). It had a strong correlation with mean PA pressure (R = 0.94; P < .001). Right ventricular MPI decreased significantly in responders (range 20%-44%, mean 25%) with a 5% increase in nonresponders.

CONCLUSIONS

Right ventricular MPI in pediatric IPAH correlates with mean PA pressure and response to therapy. This study suggests that this noninvasive Doppler index may be useful to follow up children with IPAH, particularly when tricuspid regurgitation data are insufficient.

Preliminary Experience With Bosentan as Initial Therapy in Childhood Idiopathic Pulmonary Arterial Hypertension

Since September 2001, 7 consecutive patients with childhood idiopathic pulmonary arterial hypertension (IPAH), a rapidly progressive and fatal condition, have been treated with combinations of bosentan, and other therapies (sildenafil/warfarin/epoprostenol), at our institution. Survival and clinical status in these patients were compared with a group of 12 historic control patients who were diagnosed prior to 1997 and received only conventional medical therapy. Survival in the bosentan-treated subjects was better than among historic controls with comparable disease severity (log rank, p = 0.04). Our findings indicate treatment with bosentan permits a delay in IPAH disease progression and, in combination with other therapies, improves survival compared with historic control patients.

Effects of Long-Term Bosentan in Children With Pulmonary Arterial Hypertension

OBJECTIVES

This study investigated the long-term outcome of children with pulmonary arterial hypertension (PAH) treated with bosentan therapy, with or without concomitant prostanoid therapy.

BACKGROUND

Bosentan, an oral endothelin ET(A)/ET(B) receptor antagonist, improves hemodynamics and exercise capacity in adults with PAH; however, limited data are available on its long-term effects in children.

METHODS

In this retrospective study, 86 children with PAH (idiopathic, associated with congenital heart or connective tissue disease) started bosentan with or without concomitant intravenous epoprostenol or subcutaneous treprostinil therapy. Hemodynamics, World Health Organization (WHO) functional class, and safety data were collected.

RESULTS

At the cutoff date, 68 patients (79%) were still treated with bosentan, 13 (15%) were discontinued, and 5 (6%) had died. Median exposure to bosentan was 14 months. In 90% of the patients (n = 78), WHO functional class improved (46%) or was unchanged (44%) with bosentan treatment. Mean pulmonary artery pressure and pulmonary vascular resistance decreased (64 +/- 3 mm Hg to 57 +/- 3 mm Hg, p = 0.005 and 20 +/- 2 U x m2 to 15 +/- 2 U x m2, p = 0.01, respectively; n = 49). Kaplan-Meier survival estimates at one and two years were 98% and 91%, respectively. The risk for worsening PAH was lower in patients in WHO functional class I/II at bosentan initiation than in patients in WHO class III/IV at bosentan initiation.

CONCLUSIONS

These data suggest that bosentan, an oral endothelin ET(A)/ET(B) receptor antagonist, with or without concomitant prostanoid therapy, is safe and efficacious for the treatment of PAH in children.

Idiopathic pulmonary arterial hypertension in children

PURPOSE OF REVIEW

Until recently, the diagnosis of idiopathic pulmonary arterial hypertension was virtually a death sentence, particularly for children. Although there is no cure for idiopathic pulmonary arterial hypertension, recent medical advances have dramatically changed the course of this disease in children. A review of some of the latest medical advances will provide the reader with a better understanding of the most current treatment options for children with idiopathic pulmonary arterial hypertension.

RECENT FINDINGS

The literature reviewed demonstrate sustained clinical and hemodynamic improvement in children with various types of pulmonary arterial hypertension as well as increased survival in patients with idiopathic pulmonary arterial hypertension using current treatment strategies.

SUMMARY

This article will provide an overview of how the current diagnostic and treatment strategies of idiopathic pulmonary arterial hypertension in children have advanced over the last several years and how this impacts on clinical practice.

Severe paediatric pulmonary hypertension: new management strategies

Pulmonary hypertension is a significant complication in many paediatric disease states. This article discusses current understanding of pulmonary hypertension and includes definition, diagnosis, and management. A description of the latest advances in targeted pharmacological therapy in children is also provided as well as impact on morbidity and mortality.

Primary pulmonary hypertension in children may have a different genetic background than in adults

Mutations of the bone morphogenetic protein receptor II (BMPR2) gene on chromosome 2q33 can cause familial primary pulmonary hypertension (PPH) and may occur in 26% adult patients with sporadic disease. Other disease-related genes have been localized to chromosomes 2q31 (PPH2) and 12q13 (ALK1). The genetic background in affected children remains unclear. Thirteen children (age at diagnosis, 6 mo to 13 y; mean, 5.6 +/- 3.9 y) with invasively confirmed PPH were screened for BMPR2 mutations using denaturing HPLC and sequence analysis. In addition, all children were scanned for BMPR2 deletions by Southern blot analysis. Pulmonary artery pressure was assessed using echocardiography at rest and during exercise in 57 family members of six infants. The six families were subjected to linkage analysis. None of the 13 children had a BMPR2 mutation or deletion. Linkage to chromosome 2 or 12 could not be confirmed in any of the families investigated. In all assessed families, both parents of the index patient and/or members of both branches revealed an abnormal pulmonary artery systolic pressure (PASP)-response to exercise. PPH in children may have a different genetic background than in adults. We postulate a recessive mode of inheritance in a proportion of infantile cases.

Medical therapy for pulmonary arterial hypertension: ACCP evidence-based clinical practice guidelines

Pulmonary arterial hypertension (PAH) is often difficult to diagnose and challenging to treat. Untreated, it is characterized by a progressive increase in pulmonary vascular resistance leading to right ventricular failure and death. The past decade has seen remarkable improvements in therapy, driven largely by the conduct of randomized controlled trials. Still, the selection of most appropriate therapy is complex, and requires familiarity with the disease process, evidence from treatment trials, complicated drug delivery systems, dosing regimens, side effects, and complications. This chapter will provide evidence-based treatment recommendations for physicians involved in the care of these complex patients. Due to the complexity of the diagnostic evaluation required, and the treatment options available, it is strongly recommended that consideration be given to referral of patients with PAH to a specialized center.

Outcomes in Children With Idiopathic Pulmonary Arterial Hypertension

Background— Treatment for idiopathic pulmonary arterial hypertension in children includes calcium channel blockade (CCB) for acute responders with vasodilator testing and chronic epoprostenol for nonresponders. We sought to determine parameters associated with survival and treatment success.

Methods and Results— A previously identified cohort of 77 children diagnosed between 1982 and 1995 with idiopathic pulmonary arterial hypertension was followed up through 2002. For acute responders treated with CCB (n=31), survival at 1, 5, and 10 years was 97%, 97%, and 81%, respectively; treatment success was 84%, 68%, and 47%, respectively. Survival for all children treated with epoprostenol (n=35) at 1, 5, and 10 years was 94%, 81%, and 61%, respectively; treatment success was 83%, 57%, and 37%, respectively. Because of the inconsistent availability of epoprostenol before 1995, we defined a “recent medical era” subset by excluding children from the total 77 patient cohort for whom epoprostenol was recommended but was unavailable. Survival in the recent medical era (n=44) at 1, 5, and 10 years was 97%, 97%, and 78%; treatment success was 93%, 86%, and 60%, respectively. Treatment success on CCB decreased significantly when acute responders became nonresponders. Age at diagnosis predicted treatment success in the recent medical era.

Conclusions— Survival for children with idiopathic pulmonary arterial hypertension has significantly improved with CCB and epoprostenol. Children who are acute responders are treated with CCB; they are treated with epoprostenol if they become nonresponders. The decrease in survival and in treatment success after 5 years in all children supports the role for transplant evaluation before treatment failure.

Traitement de l'hypertension artérielle pulmonaire de l'enfant

Treatment strategies for pulmonary hypertension in children have dramatically evolved. Traditional therapy with calcium channel blockers and pulmonary transplantation is only indicated in selected patients and does not reduce mortality very significantly. New pulmonary vasodilators are emerging from recent trials in the adult population. Their indications are based on the patient's NYHA classification. The epoprostenol (prostacyclin, Flolan) has shown reduction in mortality and improvement in functional symptoms in pediatric patients. The frequent side effects and continuous intravenous infusion limit the indication of prostacyclin in NYHA class IV children. The endothelin receptor blocker bosentan (Tracleer) is an orally given agent. It improves functional symptoms in adults and hemodynamic measures in children. It can be started in children with moderate functional symptoms (NYHA class II and III). The type V phosphodiesterase inhibitor sildenafil (Viagra) is being evaluated and may represent a promising therapy in the future. Invasive strategies like catheter-based atrial septostomy may be useful in particular cases. Randomized-controlled studies are urgently needed to evaluate the safety and efficacy of these new therapies.

Prognosis of Pulmonary Arterial Hypertension*

Although idiopathic pulmonary arterial hypertension is perceived as a progressive disease with a uniformly poor outcome, the natural history of disease is heterogeneous, with some patients dying within months of diagnosis and others living for decades. The course of the disease has also been altered by advances in medical therapies. The outcome of patients with other types of pulmonary arterial hypertension (PAH) has been less well characterized. Assessment of prognosis of such patients is important, as it influences both medical therapy and referral for transplantation. This chapter will provide evidence based recommendations to assess the prognosis of patients with PAH.

Pulmonary arterial hypertension in children

Pulmonary arterial hypertension is a serious progressive condition with a poor prognosis if not identified and treated early. Because the symptoms are nonspecific and the physical findings can be subtle, the disease is often diagnosed in its later stages. Remarkable progress has been made in the field of pulmonary arterial hypertension over the past several decades. The pathology is now better defined, and significant advances have occurred in understanding the pathobiologic mechanisms. Risk factors have been identified, and the genetics have been characterized. Advances in technology allow earlier diagnosis as well as better assessment of disease severity. Therapeutic modalities such as new drugs, e.g., epoprostenol, treprostinil, and bosentan, and surgical/interventional options, e.g., transplantation and atrial septostomy, which were unavailable several decades ago, have had a significant impact on prognosis and outcome. Thus, despite our inability to cure pulmonary arterial hypertension, advances in medical treatments over the past two decades have resulted in significant improvement in outcomes for children with various forms of pulmonary arterial hypertension. This report is a review the current state of the art for pulmonary arterial hypertension in 2004, with an emphasis on childhood pulmonary arterial hypertension and specific recommendations for current practice and future directions.

Treatment of primary pulmonary hypertension with oral sildenafil

Sildenafil, a selective phosphodiesterase-5 inhibitor, was administered orally to a 14-year-old girl with primary pulmonary hypertension (PPH) at a dose of 0.5 mg/kg/4 h on a daily basis, increased to doses of 1 and 2 mg/kg at monthly intervals. Following therapy, oxygen saturation increased and exercise capacity improved significantly, but with no change in pulmonary haemodynamics. No side-effects were noted. Sildenafil may be beneficial in children with PPH, but the mechanism of benefit is unclear.

Lower airway obstruction, bronchial hyperresponsiveness, and primary pulmonary hypertension in children

We investigated the prevalence and reversibility of lower airway obstruction (LAO) and its correlation with pulmonary artery pressure in children with primary pulmonary hypertension (PPH). The analysis was performed retrospectively in a cohort of children with PPH between 5-18 years of age. PPH was defined as mean pulmonary artery pressure (PAPm) >25 mmHg at rest, or >30 mmHg during exercise, with normal pulmonary capillary wedge pressure in the absence of other causes. Lower airway function was assessed by spirometry and maximal expiratory flow-volume curves. Lung volumes were measured by body plethysmography. Patients were assigned according to their pattern of lung function into "normal," "obstructive," and "restrictive" groups. The reversibility of LAO was defined as an increase of > or = 15% from baseline in forced expiratory volume at 1 sec (FEV1) and/or > or =20% in forced expiratory flow at 25-75% of forced vital capacity (FEF25-75%) in response to nebulized albuterol. An "obstructive" pattern was found in 23 children (59%), a "restrictive" pattern in 2 children (5%), and a "normal" pattern in 14 children (36%). Response to bronchodilator was documented in 78% of children with an "obstructive" pattern and in 22% of those with a "normal" pattern. The PAPm showed a significant positive correlation with the TLC, RV, and RV/TLC, but a negative one with the ratio FEV1/FVC. Our findings suggest that reversible LAO is the most common lung function abnormality among pediatric patients with PPH. Whether airway reactivity is a cause of or the result of PPH remains to be determined.

Paradoxical increase of pulmonary vascular resistance during testing of inhaled iloprost

The case of a 14 month old girl with primary pulmonary hypertension treated with domiciliary oxygen is described. After invasive evaluation and testing of nitric oxide with very good response, the testing was repeated to study the effect of inhaled iloprost on pulmonary vascular resistance (PVR). An unexpected and severe increase of PVR was observed, rising from 392 dynes x s x cm(-5) with oxygen to a maximum of 1192 dynes x s x cm(-5) with oxygen and iloprost. Underlying ventilatory and technical problems were excluded. While inhaled iloprost has been described to be highly effective in the treatment of primary pulmonary hypertension, the possibility of contrary "paradoxical" reactions in isolated patients is emphasised, with a dramatic increase of PVR and a possible adverse outcome.

Recent advances in pulmonary vascular disease

There have been remarkable advances in our understanding of the pathobiology of pulmonary hypertension. A region on chromosome 2 encoding bone morphogenetic receptor type 2 has been identified to underlie familial and many cases of sporadic primary pulmonary arterial hypertension. The vasoactive mediators, discovered and defined by vascular biologists, have been translated into promising treatments of human disease. Prostacyclin, endothelin receptor blockers, sildenafil, and nitric oxide have been applied therapeutically to limit, and occasionally reverse, the inexorable damage to the pulmonary circulation initiated by recently identified genetic and environmental triggers of pulmonary arterial hypertension.

Rapid regression of primary pulmonary hypertension

A 14 month old child presented for investigation of tachypnoea. No parenchymal lung disease was shown on chest x ray. On echocardiography there was normal intracardiac anatomy with significant pulmonary hypertension. At cardiac catheterisation the presence of primary pulmonary hypertension was confirmed, with a partial response to inhaled nitric oxide (80 ppm) and 100% oxygen. The child was referred for assessment for heart-lung transplantation while maintained on oxygen, inhaled nitric oxide, and nifedipine. Repeat cardiac catheterisation two months after presentation showed complete normalisation of the pulmonary artery pressures.

Diagnosis and treatment of severe pediatric pulmonary hypertension

Advances in the treatment of pulmonary hypertension during the past decade have dramatically improved patient survival. Many of these advances are based on improved understanding of the vascular biology of the normal and hypertensive pulmonary circulations. Pulmonary hypertension is an important determinant of morbidity and mortality in patients with many pediatric diseases, including congenital heart disease. This article describes current diagnostic strategies and treatments for patients with primary and secondary pulmonary hypertension.

Rapid regression of primary pulmonary hypertension

A 14 month old child presented for investigation of tachypnoea. No parenchymal lung disease was shown on chestx ray. On echocardiography there was normal intracardiac anatomy with significant pulmonary hypertension. At cardiac catheterisation the presence of primary pulmonary hypertension was confirmed, with a partial response to inhaled nitric oxide (80 ppm) and 100% oxygen. The child was referred for assessment for heart–lung transplantation while maintained on oxygen, inhaled nitric oxide, and nifedipine. Repeat cardiac catheterisation two months after presentation showed complete normalisation of the pulmonary artery pressures.

Diagnosis and management of primary pulmonary hypertension

Pulmonary arterial hypertension in children can occur secondary to shunt lesion like ventricular septal defect, patent ductus arteriosus or it may be idiopathic, the so-called primary pulmonary hypertension (PPH). The progression of PPH is usually rapid in children as compared to adults and the mean survival is 2-3 years after the diagnosis is made. Histological changes in the form of medical muscular hypertrophy, intinal hyperplasia and later angiornatous, plexiform lesions occur in pulmonary vasculature. The pulmonary vasculature normally is a high flow, low resistance circuit and allows large blood flow without marked increase in pulmonary arterial pressure. However, with prolonged increased flow or any other vasoconstrictor stimulus, histological changes start occurring in the pulmonary bed resulting in increasing pressure in pulmonary artery. Right ventricular hypertension follows resulting in right ventricular hypertrophy and later dysfunction. Life threatening arrhythmias may result in sudden death in some of these patients. Clinical presentation is in the form of exertional dyspnoea with syncope at times. Over 50% of children with PPH are helped by vasodilators. They may be treated with calcium channel blockers (e.g. nifedipine, dose titrated to blood pressure) orally. Those not responding to oral vasodilators can be put on chronic inhaled nitric oxide or continuous intravenous prostacyclin infusion. Chronic anticoagulation therapy may also increase survival. In symptomatic cases, blade/balloon atrial septostomy may increase survival in patients of PPH with intact atrial sptum. For children not responding to medical therapy, lung transplantation may be the answer in near future.

Vasodilator therapy for primary pulmonary hypertension in children

BACKGROUND

This report presents 13 years of experience with vasodilator therapy for primary pulmonary hypertension (PPH) in children. Two eras were involved: between 1982 and 1987, oral calcium channel blockers were the only agents available for long-term therapy; after 1987, prostacyclin (PGI2) has been available for long-term intravenous use.

METHODS AND RESULTS

Seventy-four children underwent short-term vasodilator testing with intravenous PGI2. Those who manifested pulmonary vasodilation ("acute responders") were treated with oral calcium channel blockers. Until 1987, "acute nonresponders" were treated in the same way as long as they had no serious side effects. When PGI2 became available for long-term administration, all nonresponders, as well as those who failed to improve clinically and hemodynamically on calcium channel blockers, were treated with long-term PGI2. In the 31 responders, calcium channel blockers improved survival compared with the 43 nonresponders (P=0.0002). Survival was also better in 24 PGI2-treated nonresponders compared with 22 nonresponders for whom PGI2 was unavailable (P=0.0005) as well as in all children who failed conventional therapy (n=31; P=0.002).

CONCLUSIONS

Long-term vasodilator therapy improves survival in children with PPH. In acute responders, oral calcium channel blockers generally suffice. In both nonresponders to short-term testing and responders who fail to improve on calcium channel blockers, continuous intravenous infusion of PGI2 improves survival.

Airway responsiveness to inhaled albuterol in patients with pulmonary hypertension

We studied patients with pulmonary hypertension who had evidence of bronchial responsiveness to inhaled albuterol. The records of all patients evaluated for lung transplantation were reviewed: the charts of patients with pulmonary hypertension, either primary (PPH, n = 46) or Eisenmenger's syndrome (n = 12), were abstracted. Measurements of lung function revealed equal numbers of patients with normal, restrictive, obstructive, and mixed abnormalities. None were more than moderate. Airway responsiveness was defined as an increase of forced expiratory volume in 1 second (FEV1) > 15% or forced expiratory flow between 25% and 75% of the vital capacity (FEF25-75) > 25%. Of the 24 PPH and nine Eisenmenger's patients, 14 and four, respectively, had reversible airflow obstruction. These patients were more likely to have a history of atopic disease and to have responded to calcium channels blockers during hemodynamic monitoring. They did not have more severe pulmonary hypertension, as measured by hemodynamic monitoring. Four patients had a history of asthma, which required hospitalization in three. Reversible airflow obstruction occurred in half of the patients with pulmonary hypertension and was clinically important in at least three.

Graded balloon dilation atrial septostomy in severe primary pulmonary hypertension. A therapeutic alternative for patients nonresponsive to vasodilator treatment

OBJECTIVES

We sought to investigate the acute hemodynamic effects of graded balloon dilation atrial septostomy (BDAS) and to define the long-term impact of this procedure on New York Heart Association functional class and survival in adult patients with primary pulmonary hypertension (PPH).

BACKGROUND

Current treatment strategies for patients with severe and refractory PPH are limited by either technical difficulties and high mortality or cost.

METHODS

We studied 15 patients with severe PPH. BDAS was successfully performed in all patients by crossing the interatrial septum with a Brockenbrough needle, followed by progressive dilation of the orifice with a Mansfield balloon in a hemodynamically controlled, step-by-step manner.

RESULTS

BDAS caused an immediate significant fall in right ventricular end-diastolic pressure and in systemic arterial oxygen saturation and an increase in cardiac index. One patient died, and 14 survived the procedure and significantly improved their mean functional class (from 3.57 +/- 0.6 to 2.07 +/- 0.3 [mean +/- SD], p < 0.001). Exercise endurance (6-min test) also improved from 107 +/- 127 to 217 +/- 108 m (p < 0.001). Because of spontaneous closure, BDAS was repeated in four patients. The survival rate among patients who survived the procedure was 92% at 1, 2 and 3 years, which is better than that for historical control PPH patients (73%, 59% and 52%, respectively).

CONCLUSIONS

With careful monitoring, BDAS is a safe and useful palliative treatment for selected patients with severe PPH.

Percutaneous pulmonary endoarterial biopsy in an experimental model of pulmonary hypertension

STUDY OBJECTIVES

The aims of this study were: to evaluate the performance of a novel arterial biopsy catheter in obtaining pulmonary endovascular samples in hypertensive dogs; to compare the results of pulmonary endoarterial biopsy in hypertensive vs normotensive dogs; and to assess the histologic changes in the hypertensive model.

DESIGN AND INTERVENTIONS

Thirty-four dogs (27 with normal pulmonary arterial pressures and seven with pulmonary hypertension) were catheterized through an external jugular vein to obtain endovascular biopsy samples from distal pulmonary arteries 2 to 3 mm in luminal diameter. To induce pulmonary hypertension, seven dogs were given repeated infusions of 0.6- to 0.9-mm ceramic microspheres into the superior vena cava. Endoarterial samples were obtained at pulmonary systolic arterial pressures ranging from 10 to 110 mm Hg.

MEASUREMENTS AND RESULTS

Sixty-two biopsy catheterization procedures were performed in the 34 dogs. After 12 initial procedures of technique refinement, endoarterial samples were obtained in each of the last 50 procedures (21 in normotensive dogs and 29 in hypertensive dogs). The average number of endovascular biopsy samples retrieved was 7.1 (range, 2 to 12) from a mean of 8.6 (range, 2 to 15) biopsy attempts per catheterization (success rate=83%). The average biopsy piece measured 1.13 mm in length, 0.33 mm in depth, and up to 1.0 mm in width. The biopsy success rates and endoarterial sample sizes were similar in normotensive and hypertensive dogs. Smooth muscle cells and endothelial cells were grown from the biopsy samples. There were no significant procedural complications, except for one self-limited hemorrhage. Histologically, samples obtained from dogs with pulmonary hypertension showed characteristic changes when compared with biopsies from normotensive dogs.

CONCLUSION

This new endoarterial biopsy catheter was safe and effective when used to obtain pulmonary endoarterial samples in dogs with normal and experimentally elevated pulmonary arterial pressures. The quality and quantity of the biopsy samples allowed identification of pathologic changes.

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.

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.

Holmes heart in the adult: transesophageal echocardiographic findings and long-term natural survival

We describe a 59-year-old patient with Holmes heart (single ventricle with normally related great arteries). To our knowledge, this is the oldest patient in the literature with this rare congenital heart disease and the oldest one with single ventricle and unrestricted pulmonary blood flow who has developed Eisenmenger's physiology. A transesophageal echocardiographic examination showed a single large ventricle that was a morphologic left ventricle with a normally appearing aorta originating from this chamber and a normally related pulmonary artery arising from a hypoplastic right infundibulum located anteriorly-superiorly and to the left of the left ventricle. The cardiac catheterization confirmed the echocardiographic findings and revealed a pulmonary artery pressure of 160/60 mmHg. There were no systolic gradients across the pulmonary and aortic outflow tracts. The estimated pulmonary vascular resistance was 2720 dynes-sec-cm-5. Oximetry showed oxygen saturation in the left ventricle of 84% and femoral artery saturation of 77.7%. Our report further demonstrates that pulmonary stenosis is not the ultimate determinant of prolonged natural survival in patients with single ventricle. Since this patient is too old for cardiopulmonary transplantation, we plan to follow him conservatively with medical therapy.