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

Medical therapeutics for pulmonary arterial hypertension: from basic science and clinical trial design to evidence-based medicine

Pulmonary arterial hypertension is a severe disease with poor prognosis, caused by obliteration of the pulmonary vasculature as a result of pulmonary-vascular remodeling, active vasoconstriction and in situ thrombosis. Left untreated, pulmonary arterial hypertension results in right-ventricular failure and death. There has been dramatic progress in the treatment of pulmonary arterial hypertension during recent years. A remarkable number of randomized-controlled trials with agents known to target specific abnormalities present in pulmonary arterial hypertension have been completed. Most commonly, therapeutic efficacy was judged by the ability of the drug under study to improve exercise capacity and to decrease the rate of severe complications. Completed clinical trials have mainly evaluated patients with relatively advanced disease. Despite these advances, responses to therapy in pulmonary arterial hypertension are not uniformly favorable and frequently incomplete. In addition, the methods of delivery and the adverse effect profile of the currently available pulmonary arterial hypertension-specific drugs create further management difficulties. Based on newly identified pathobiologic abnormalities in the pulmonary vasculature, future studies are likely to focus on the discovery of new therapeutic targets. Clinical trial design will continue to evolve in an attempt to enable inclusion of patients with less advanced disease and evaluation of treatment combinations or comparisons of the currently approved drugs.

Pericardial effusion in pulmonary arterial hypertension

Abstract Pulmonary arterial hypertension (PAH) is a serious condition that can lead to right heart failure and death. Pericardial effusion in PAH is associated with significant morbidity and mortality, and its pathogenesis is complex and poorly understood. There are few data on the prevalence of pericardial effusion in PAH, and more importantly, the management of pericardial effusion is controversial. Current literature abounds with case reports, case series, and retrospective studies that have limited value for assessing this association. Hence, we summarize the available evidence on this ominous association and identify areas for future research.

Risk of death and need for transplantation in chronic pulmonary hypertension

BACKGROUND

Echo-Doppler parameters that exemplify right ventricular (RV) outflow dynamics and measures of annular tissue Doppler imaging to assess left ventricular (LV) and RV diastolic function, known to be affected in chronic pulmonary hypertension (cPH), have never been studied to determine if they could be predictive of mortality or need for transplantation 1-year after follow-up.

METHODS

Numerous echo-Doppler parameters of RV and LV performance were recorded from 120 patients. This patient population was divided into 3 groups. Group I had no PH, group II had cPH but no documented death or need for either lung or heart transplantation, at 1-year follow-up after their initial echocardiogram whereas group III had cPH and patients had either died or required heart and/or lung transplantation during the same time period.

RESULTS

Analysis of variance was first used to identify which echo-Doppler variables were significant among the studied groups. A logistic regression analysis was then performed to identify predictive variables of the occurrence death and need for transplantation. Finally, a multiple regression analysis was used between groups II and III to identify which echo-Doppler variables were most useful in identifying severe cPH patients at risk of the prespecified events.

CONCLUSIONS

Even though older patients with worse RV fractional area change might be considered at risk of worse prognosis in patients with severe cPH, only a low mitral annular early diastolic velocity was useful in identifying which of those individuals were at highest risk of death or in need of transplantation.

When to initiate intravenous therapy and/or refer

Intravenous (IV) prostacyclin (epoprostanol) and its analogs (iloprost and treprostinil) are effective in treating pulmonary artery hypertension (PAH). Although prostacyclins are available for inhaled and subcutaneous delivery, IV administration of prostacyclins, sometimes in combination with other agents, such as bosentan or sildenafil, is considered the most aggressive method to manage PAH. This report attempts to help clinicians determine when to initiate IV treatment of PAH and when to refer a patient with PAH to a center for treatment. IV prostacyclin therapy initiation is suggested when patients exhibit World Health Organization functional class IV symptoms. The Registry to EValuate Early And Long-term Pulmonary Arterial Hypertension disease management (REVEAL) risk calculator can help determine a patient's 1-year mortality with PAH and characterize the clinical course, treatment, and predictors of outcomes in patients with PAH. Referring physicians can screen their patients for PAH and refer even before the diagnosis has been confirmed so that the center can facilitate the diagnostic process and provide suggestions for initial therapy selection and provide other collaborative and supportive services. Alternatively, the physician can diagnose and initiate early therapy with a plan to involve the pulmonary hypertension center at the need for IV therapy or consideration for transplantation, working closely with the patient to ensure stability. Physicians and pulmonary centers must develop good methods of communication to ensure effective diagnosis and management.

Right isovolumic contraction velocity predicts survival in pulmonary hypertension

BACKGROUND

Right ventricular function is a strong determinant of prognosis in severe pulmonary hypertension.

METHODS

The aim of this study was to evaluate the prognostic value of estimates of right ventricular function obtained by echocardiography and Doppler tissue imaging and of functional class and 6-min walk distance (6MWD) in 142 patients with either pulmonary arterial hypertension (n = 104) or chronic thromboembolic pulmonary hypertension (n = 38). Echocardiography was prospectively performed, and demographics, medications, associated medical conditions, New York Heart Association class, and 6MWD at inclusion in addition to vital status, transplantation, and hospital admission related to pulmonary hypertension at follow-up were then collected by review of the medical records.

RESULTS

Variables associated with overall survival by univariate analysis were 6MWD (P = .009), functional class (P = .024), tricuspid annular plane systolic excursion (P = .03) and isovolumic peak velocity at the tricuspid annulus (IVCv) (P = .003). On multivariate analysis, IVCv (P = .015) and 6MWD (P = .016) were the only independent predictors of survival. Kaplan-Meier estimates of survival at 1 year were 95% in patients with IVCv > 9 cm/sec and 80% in those with IVCv ≤ 9 cm/sec (P = .002). Intraobserver and interobserver variability of IVCv measurement were 5% and 9%, respectively.

CONCLUSIONS

Measurement of right ventricular function by Doppler tissue imaging, an easy, noninvasive, and reproducible method, is an independent predictor of clinical outcomes in patients with severe pulmonary hypertension.

The diagnostic accuracy of Doppler echocardiography in assessment of pulmonary artery systolic pressure: a meta-analysis

BACKGROUND

Transthoracic echocardiography is commonly used to estimate pulmonary arterial systolic pressure (PASP) and to diagnose pulmonary hypertension (PH). However, some recent studies have questioned the accuracy of Doppler echocardiography (DE) in the assessment of PASP. The present meta-analysis was performed to estimate the accuracy, sensitivity, and specificity of DE in the assessment of PASP.

METHODS

A literature search and data extraction of English and non-English articles reported from May 1984 to January 2009 was performed independently by 2 investigators using MEDLINE and EMBASE databases. Articles were included if they compared DE with right heart catheterization (RHC) in the assessment of PASP. Nine articles met our criteria and were included in our meta-analysis. We conducted a meta-analysis of the results of these articles using fixed- and random-effect models to estimate the accuracy, sensitivity, and specificity of DE in the assessment of PASP.

RESULTS

The correlation between PASP estimated by DE and RHC ranged from (r = 0.65, P < 0.001) to (r = 0.97, P < 0.001). The pooled sensitivity, specificity, and accuracy of DE for the diagnosis of PH were 88% (95% confidence interval [CI], 84-92%), 56% (95% CI, 46-66%), and 63% (95% CI, 53-73%), respectively.

CONCLUSION

DE is a useful noninvasive modality to screen for PH and can reliably determine whether PASP is normal, mildly elevated, or markedly elevated. However, abnormal results from DE need to be confirmed by RHC.

Impact of pulmonary hypertension on tricuspid valve function

Pulmonary arterial hypertension (PAH) results in increased right ventricle (RV) afterload leading to RV remodeling, tricuspid regurgitation (TR), and RV failure. Though characterizing the mechanisms of TR in PAH may suggest new treatment strategies, the mechanisms leading to TR in PAH have not been characterized. In the present study, eleven porcine tricuspid valves were studied in an in vitro right heart simulator. Annular dilatations of 1.2 and 1.4 times normal area, papillary muscle (PM) displacement simulating concentric RV dilatation and eccentric RV dilatation due to concomitant left ventricle dysfunction, and two levels of PAH hemodynamics were simulated independently and in combination. Relative TR, tenting area (TA) along each coaptation line, and coaptation area (CA) of each leaflet were quantified. Results showed a significant increase (p ≤ 0.05) in TR with both increased mean pulmonary artery pressure (mPAP) and annular dilatation of 1.4 times normal. Increased mPAP significantly decreased TA but tended to increase CA, while PM displacement significantly increased TA but did not affect CA, suggesting competing effects of transvalvular pressure and leaflet tethering. Annular dilatation significantly decreased anterior and posterior CA but did not affect TA. These results may inform future TV repairs in PAH to reduce TR and improve RV hemodynamics.

Right ventricular remodeling in pulmonary hypertension

The right ventricle (RV) is in charge of pumping blood to the lungs for oxygenation. Pulmonary arterial hypertension (PAH) is characterized by high pulmonary vascular resistance and vascular remodeling, which results in a striking increase in RV afterload and subsequent failure. There is still unexploited potential for therapies that directly target the RV with the aim of supporting and protecting the right side of the heart, striving to prolong survival in patients with PAH.

Echocardiography in pulmonary arterial hypertension: from diagnosis to prognosis

Pulmonary arterial hypertension is most often diagnosed in its advanced stages because of the nonspecific nature of early symptoms and signs. Although clinical assessment is essential when evaluating patients with suspected pulmonary arterial hypertension, echocardiography is a key screening tool in the diagnostic algorithm. It provides an estimate of pulmonary artery pressure, either at rest or during exercise, and is useful in ruling out secondary causes of pulmonary hypertension. In addition, echocardiography is valuable in assessing prognosis and treatment options, monitoring the efficacy of specific therapeutic interventions, and detecting the preclinical stages of disease.

Today's and tomorrow's imaging and circulating biomarkers for pulmonary arterial hypertension

The pathobiology of pulmonary arterial hypertension (PAH) involves a remodeling process in distal pulmonary arteries, as well as vasoconstriction and in situ thrombosis, leading to an increase in pulmonary vascular resistance, right heart failure and death. Its etiology may be idiopathic, but PAH is also frequently associated with underlying conditions such as connective tissue diseases. During the past decade, more than welcome novel therapies have been developed and are in development, including those increasingly targeting the remodeling process. These therapeutic options modestly increase the patients' long-term survival, now approaching 60% at 5 years. However, non-invasive tools for confirming PAH diagnosis, and assessing disease severity and response to therapy, are tragically lacking and would help to select the best treatment. After exclusion of other causes of pulmonary hypertension, a final diagnosis still relies on right heart catheterization, an invasive technique which cannot be repeated as often as an optimal follow-up might require. Similarly, other techniques and biomarkers used for assessing disease severity and response to treatment generally lack specificity and have significant limitations. In this review, imaging as well as current and future circulating biomarkers for diagnosis, prognosis, and follow-up are discussed.

Prostanoids for Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a severe condition that markedly reduces exercise capacity and survival in the affected patient population. PAH includes primary pulmonary hypertension (PPH) and pulmonary hypertension associated with collagen vascular diseases, congenital systemic-to-pulmonary shunts, portal hypertension and HIV infection. All these conditions share virtually identical obstructive pathologic changes of the pulmonary microcirculation and probably similar pathobiologic processes. The pathophysiology is characterized by a progressive increase in pulmonary vascular resistance, leading to right ventricular failure and death. Prostacyclin is an endogenous substance that is produced by vascular endothelial cells and induces vasodilatation, inhibition of platelet activity, and antiproliferative effects. A dysregulation of prostacyclin metabolic pathways has been shown in patients with PAH and this represents the rationale for the exogenous therapeutic administration of this substance. The clinical use of prostacyclin in patients with PAH has been made possible by the synthesis of stable analogs that possess different pharmacokinetic properties but share similar pharmacodynamic effects. Experience in humans has been initially collected with epoprostenol, which is a synthetic salt of prostacyclin. Epoprostenol has a short half-life in the circulation and requires continuous administration by the intravenous route by means of infusion pumps and permanent tunnelized catheters. In addition, epoprostenol is unstable at room temperature, and the complex delivery system required is associated with several adverse effects and potentially serious complications. For these reasons, alternatives to intravenous epoprostenol have been sought and this has led to the development of analogs that can be administered subcutaneously (treprostinil), orally (beraprost sodium) or by inhalation (iloprost). Three unblinded clinical trials and several uncontrolled trials have shown that treatment with epoprostenol improved symptoms and exercise capacity in New York Heart Association (NYHA) class III and IV PAH patients and also survival in patients with PPH. Subcutaneous treprostinil improved symptoms, exercise, hemodynamics and clinical events in the largest clinical trial ever performed in PAH, but local infusion site reactions limited efficacy in a proportion of patients. Oral beraprost sodium improved exercise capacity only in patients with PPH and is the only prostacyclin analog that has also been tested in NYHA class II patients. Inhaled iloprost has improved symptoms, exercise capacity and clinical events in patients with PAH and inoperable chronic thromboembolic pulmonary hypertension. The favorable effects of prostanoids observed in all studies coupled with different profiles of adverse events and tolerability for each prostacyclin analog allow the unique opportunity to select the most appropriate compound for the individual patient with PAH.

Pulmonary hypertension in chronic hypersensitivity pneumonitis

BACKGROUND

The purpose of this study was to evaluate the prevalence and outcomes of pulmonary hypertension in chronic hypersensitivity pneumonitis and to examine the relationship between pulmonary function tests and pulmonary hypertension.

METHODS

We conducted a retrospective review of 120 patients with hypersensitivity pneumonitis seen at two centers for pulmonary diseases over a 5-year interval and identified patients with chronic hypersensitivity pneumonitis for whom both pulmonary function tests and Doppler echocardiography data were available.

RESULTS

Chronic hypersensitivity pneumonitis was identified in 83 patients and Doppler echocardiography data were available for 73 of them. Pulmonary hypertension (sPAP ≥ 50 mmHg) was detected in 14 patients (19%), and was associated with a greater risk of death (median survival = 23 months vs. 98 months; P=0.003). Patients with pulmonary hypertension were older and had a significantly decreased PaO(2). There was a weak correlation between pulmonary function parameters and the underlying sPAP, with significance for FVC, FEV(1), and PaO(2) and inversely with PaCO(2).

CONCLUSIONS

Using Doppler echocardiography for evaluation, pulmonary hypertension seems to be common in patients with chronic hypersensitivity pneumonitis, significantly impacts survival, and correlates with FVC, FEV(1), and PaO(2) and inversely with PaCO(2).

Perioperative management of pulmonary hypertension in children with critical heart disease

OPINION STATEMENT

Pulmonary hypertension (PHTN) is common to a variety of conditions occurring in infants and children presenting to the intensive care unit. A fundamental understanding of the response of the right ventricle to an increase in afterload and the clinical syndromes responsible for PHTN is essential for managing patients with PHTN and critical heart disease. There are important distinguishing features between PHTN syndromes, and although one form of PHTN may predominate, often more than one mechanism of PHTN is contributing to the pathophysiologic state. Thus, it is imperative to tailor therapies accordingly in order to optimize outcomes.

Diagnosis and assessment of pulmonary vascular disease by Doppler echocardiography

Pulmonary hypertension (PH) is a relatively misunderstood disease, partly related to the fact that many perceive PH to be a singular diagnosis. An unintended consequence of this is the misapplication of the role of the Doppler-Echocardiographic (DE) examination, as well as an underappreciation for its ability to help discern PH pathophysiology prior to right heart catheterization. Since DE often serves as the "gatekeeper" to invasive right heart catheterization, misinterpretation of the DE can lead to missed or delayed diagnosis with devastating consequences. Too often, the primary or nearly exclusive focus of the DE examination is placed on the pulmonary artery pressure estimation. Two main issues with this approach are that Doppler pressure estimations can be inaccurate and even when accurate, without integration of additional 2-D and Doppler information, the clinician will often still not appreciate the pathophysiology of the PH nor its clinical significance. This review will focus on the 2-D and Doppler features necessary to assess pulmonary vascular disease (PVD), discern the salient differences between PVD and pulmonary venous hypertension (PVH), and how to integrate these key DE parameters such that PH pathophysiology can be determined noninvasively and early in the patient workup. Overreliance on any single DE metric, and especially PA pressure estimation, detracts from the overall diagnostic potential of the DE examination. Integrating the relative balance of right and left heart findings, along with proper Doppler interpretation provides a wealth of clinical and pathophysiologic insight prior to invasive hemodynamic assessment. The end results are heightened awareness and improved identification of which patients should be referred for further invasive testing, as well the use of the DE information to compliment the findings from invasive testing.

Tricuspid annular plane systolic excursion is a robust outcome measure in systemic sclerosis-associated pulmonary arterial hypertension

OBJECTIVE

The tricuspid annular plane systolic excursion (TAPSE) strongly reflects right ventricular (RV) function and predicts survival in idiopathic pulmonary arterial hypertension (PAH). But its role in systemic sclerosis (SSc)-associated PAH has not been established. Our objective was to validate the TAPSE in the assessment of RV function and prediction of survival in SSc-PAH.

METHODS

Fifty consecutive patients with SSc-PAH who underwent echocardiography with TAPSE measurement within 1 h of clinically indicated right heart catheterization were followed prospectively. The relationship between TAPSE and measures of RV function and measures of survival was assessed.

RESULTS

The majority of the cohort were women in New York Heart Association class III/IV with severe PAH (mean cardiac index 2.4 ± 0.8 l/min/m(2)). RV function was significantly impaired (mean cardiac index 2.1 ± 0.7 vs 2.9 ± 0.8 l/min/m(2); p < 0.01) and RV afterload was significantly greater (mean pulmonary vascular resistance 11.1 ± 5.1 vs 5.8 ± 2.5 Wood units; p < 0.01) in subjects with a TAPSE ≤ 1.7 cm. The proportion surviving in the low TAPSE group was significantly lower [0.56 (95% CI 0.37-0.71) and 0.46 (95% CI 0.28-0.62) vs 0.87 (95% CI 0.55-0.96) and 0.79 (95% CI 0.49-0.93), 1- and 2-year survival, respectively]. TAPSE ≤ 1.7 cm conferred a nearly 4-fold increased risk of death (HR 3.81, 95% CI 1.31-11.1, p < 0.01).

CONCLUSION

TAPSE is a robust measure of RV function and strongly predicts survival in patients with PAH-SSc. Future studies are needed to identify the responsiveness of TAPSE to PAH-specific therapy and to assess its diagnostic utility in PAH-SSc.

Progressive changes in right ventricular geometric shortening and long-term survival in pulmonary arterial hypertension

BACKGROUND

Until now, many investigators have focused on describing right ventricular (RV) dysfunction in groups of patients with pulmonary arterial hypertension (PAH), but very few have addressed the deterioration of RV function over time. The aim of this study was to investigate time courses of RV geometric changes during the progression of RV failure.

METHODS

Forty-two patients with PAH were selected who underwent right-sided heart catheterization and cardiac MRI at baseline and after 1-year follow-up. Based on the survival after this 1-year run-in period, patients were classified into two groups: survivors (26 patients; subsequent survival of > 4 years) and nonsurvivors (16 patients; subsequent survival of < 4 years). Four-chamber cine imaging was used to quantify RV longitudinal shortening (apex-base distance change), RV transverse shortening (septum-free wall distance change), and RV fractional area change (RVFAC) between end diastole and end systole.

RESULTS

Longitudinal shortening, transverse shortening, and RVFAC measured at the beginning of the run-in period and 1 year later were significantly higher in subsequent survivors than in nonsurvivors (P < .05). Longitudinal shortening did not change during the run-in period in either patient group. Transverse shortening and RVFAC did not change during the run-in period in subsequent survivors but did decrease in subsequent nonsurvivors (P < .05). This decrease was caused by increased leftward septal bowing.

CONCLUSIONS

Progressive RV failure in PAH is associated with a parallel decline in longitudinal and transverse shortening until a floor effect is reached for longitudinal shortening. A further reduction of RV function is due to progressive leftward septal displacement. Because transverse shortening incorporates both free wall and septum movements, this parameter can be used to monitor the decline in RV function in end-stage PAH.

Evaluating factors influencing screening for pulmonary hypertension in systemic sclerosis: does disparity between available guidelines influence clinical practice?

Pulmonary arterial hypertension (PAH) is one of the leading causes of mortality in systemic sclerosis (SSc). We audited adherence with available recommendations regarding cardiopulmonary screening for PAH in SSc and explored potential factors influencing clinical practice. A retrospective case note review of 108 patients with SSc who had attended outpatient clinic over the previous year was undertaken. Records were scrutinised for evidence of previous assessment with trans-thoracic echocardiography (TTE) and pulmonary function tests (PFT), along with information regarding clinical phenotype and serological subset. The proportion of patients for whom screening had been undertaken within the previous 12 months was low, with significantly fewer having TTE compared with PFT assessment (34.7% vs. 53.1%, p = 0.014). The majority of patients had undergone TTE and PFT assessment within the previous 2 years, but a lower proportion had undergone TTE compared with PFT (69.4% vs. 82.7%, p = 0.044). There were strong trends for more frequent PFT assessment in younger patients, limited cutaneous SSc and worse previous PFT results. In contrast, the frequency of TTE assessment was not associated with previous investigation results or disease subtype. Serological profile did not influence the frequency of either TTE or PFT assessments. Disparity between available published guidelines may influence both the frequency and preference of PAH screening in SSc in clinical practice. The higher frequency of PFT assessment might reflect a perceived superiority amongst clinicians of PFT over TTE in the early identification of SSc-PAH. SSc-specific guidelines, possibly incorporating additional independent risk factors, may improve the cost-effectiveness and clinical efficacy of screening recommendations designed to ensure the early identification of PAH in patients with SSc.

Cardiopulmonary exercise testing in the assessment of pulmonary hypertension

The assessment of patients with suspected or confirmed pulmonary arterial hypertension (PAH) and secondary pulmonary hypertension (PH) continues to evolve and, in recent years, evidence demonstrating that cardiopulmonary exercise testing (CPX) provides valuable information has grown at an impressive rate. The key premise supporting the use of CPX is that certain variables obtained provide insight into the degree of ventilation/perfusion mismatching secondary to altered pulmonary hemodynamics. In this article, we discuss the pathophysiology of PAH and secondary PH and its impact on cardiac function, review the clinical presentation of patients with elevated pulmonary pressures and outline a case for the use of CPX as an integral assessment technique, discuss CPX technology and testing procedures, and review the current state of available evidence and provide clinical recommendations for CPX in the setting of known or suspected PAH and secondary PH.

Right ventricular dysfunction and failure in chronic pressure overload

Right ventricular (RV) dysfunction is the main cause of death in pulmonary arterial hypertension (PAH). Our understanding of the pathophysiology of RV dysfunction is limited but improving. Methods to better diagnose RV dysfunction earlier and treatments specifically designed to minimize or reverse the remodeling process are likely to improve outcomes. We review the current understanding of RV dysfunction in chronic pressure overload and introduce some novel insights based on recent investigations into pathophysiology, diagnosis, and treatment.

Clinical and prognostic relevance of echocardiographic evaluation of right ventricular geometry in patients with idiopathic pulmonary arterial hypertension

The aim of the present study was to assess the clinical and prognostic significance of right ventricular (RV) dilation and RV hypertrophy at echocardiography in patients with idiopathic pulmonary arterial hypertension. Echocardiography and right heart catheterization were performed in 72 consecutive patients with idiopathic pulmonary arterial hypertension admitted to our institution. The median follow-up period was 38 months. The patients were grouped according to the median value of RV wall thickness (6.6 mm) and the median value of the RV diameter (36.5 mm). On multivariate analysis, the mean pulmonary artery pressure (p = 0.018) was the only independent predictor of RV wall thickness, and age (p = 0.011) and moderate to severe tricuspid regurgitation (p = 0.027) were the independent predictors of RV diameter. During follow-up, 22 patients died. The death rate was greater in the patients with a RV diameter >36.5 mm than in patients with a RV diameter ≤36.5 mm: 15.9 (95% confidence interval 9.4 to 26.8) vs 6.6 (95% confidence interval 3.3 to 13.2) events per 100-person years (p = 0.0442). In contrast, the death rate was similar in patients with RV wall thickness above or below the median value. However, among the patients with a RV wall thickness >6.6 mm, a RV diameter >36 mm was not associated with a poorer prognosis (p = 0.6837). In conclusion, in patients with idiopathic pulmonary arterial hypertension, a larger RV diameter is a marker of a poor prognosis but a greater RV wall thickness reduces the risk of death associated with a dilated right ventricle.

Accuracy of noninvasively determined pulmonary artery systolic pressure

The noninvasive estimation of pulmonary artery systolic pressure (PASP) has become a standard component of the echocardiographic examination. Our aim was to evaluate the accuracy of this modality in a large series of unselected studies obtained in clinical practice. All right heart catheterizations during a 4-year period were reviewed. Studies with echocardiographic findings available within 48 hours were evaluated for PASP agreement. In an effort to mirror clinical practice, the right heart catheterization findings were used as the reference standard and the PASP values were taken directly from the respective clinical reports. Overall, 792 right heart catheterization-echocardiogram pairs were identified. Echocardiographic PASP could not be estimated in 174 of these studies (22.0%). The correlation between modalities was moderate, but agreement was poor (bias 9.0%, 95% limits of agreement -53.2% to 71.2%, r = 0.52, p <0.001). Misclassification of clinical PASP categories occurred more often than not (54.4%). Multivariate analysis using multiple potential sources of error could only account for 3.2% of the total variation in the discrepancy between the study modalities (p = 0.003). In conclusion, noninvasively estimated PASP had limited agreement with the invasively determined PASP, and misclassification of PASP clinical categories occurred frequently. Given the widespread use of echocardiographically determined PASP, these data are in need of replication in a large prospective study.

Measuring the heart in pulmonary arterial hypertension (PAH): implications for trial study size

PURPOSE

To calculate the sample size for a theoretical pulmonary arterial hypertension (PAH) randomized controlled trial (RCT) by using cardiovascular magnetic resonance (CMR) imaging to determine the repeatability of measures between two scans.

MATERIALS AND METHODS

Two same-day examinations from 10 PAH patients were analyzed manually and semiautomatically. Study size was calculated from the standard deviation (SD) of repeatability. Different approaches to right-ventricle (RV) mass were investigated, agreement between methods tested and interobserver reproducibility measured by Bland-Altman analysis to explore how the PAH heart might be best measured.

RESULTS

Repeatability was good for almost all manually-measured indices but poor for semiautomated measurement of RV mass and left-ventricle (LV) end-diastolic volume (EDV). Thus, for an RCT (power, 80%; significance level, 5%) analyzing "outcome" indices (RVEDV, LVEDV, RV ejection fraction, and RV mass; anticipated change: 10 mL, 10 mL, 3%, and 10 g, respectively) manually, 34 patients are required compared to 78 if analysis is semiautomated. RV mass was repeatable if the interventricular septum was divided between ventricles or if wholly apportioned to the LV. Limits of agreement between manual and semiautomated analyses were unsatisfactory for RV measures and interobserver reproducibility was worse for semiautomated than manual analysis.

CONCLUSION

Manual is more robust than semiautomated analysis and at present should be favored in RCTs in PAH as it leads to lower sample size requirements.

Hemodynamics in pulmonary arterial hypertension (PAH): do they explain long-term clinical outcomes with PAH-specific therapy?

Background

Pulmonary arterial hypertension (PAH) has witnessed dramatic treatment advances over the past decade. However, with the exception of epoprostenol, data from short-term randomized controlled trials (RCTs) have not shown a benefit of these drugs on survival. There remains a need to differentiate between available therapies and current endpoint responses which in turn, could be used to guide treatment selection and provide long-term prognostic information for patients.

Methods

We performed a systematic literature search of MEDLINE and EMBASE databases for RCTs of PAH-specific therapy published between January 1980 and May 2009. Articles were selected if they contained a placebo comparator and described hemodynamic changes from baseline. We applied the weighted mean change in hemodynamic variables to the equation developed by the National Institutes of Health (NIH) Registry to estimate long-term survival with each therapy.

Results

Ten RCTs involving 1,635 patients met the inclusion criteria. Suitable hemodynamic data were identified for bosentan, sitaxentan, sildenafil, epoprostenol, beraprost and treprostinil. 77.6% of patients were female and the mean (SD) age was 46.5 ± 4.9 years. 55.5% of patients had idiopathic PAH (iPAH), 23.9% PAH related to connective tissue disease, and 18.2% PAH related to congenital heart disease. Based on the effects observed in short-term trials and, relative to placebo, all analyzed therapies improved survival. The estimated 1-year survival was 78.4%, 77.8%, 76.1%, 75.8%, 75.2%, and 74.1% for epoprostenol, bosentan, treprostinil, sitaxentan, sildenafil, and beraprost, respectively. These estimates are considerably lower than the 1-year observed survival reported in several open-label and registry studies with PAH-specific therapies: 88% - 97%.

Conclusion

When applied to the NIH Registry equation, hemodynamic changes from baseline appear to underestimate the survival benefits observed with long-term PAH therapy.

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

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

The ratio of the atrial areas reflects the clinical status of patients with pulmonary arterial hypertension

PURPOSE

Echocardiography is useful not only for detecting pulmonary hypertension (PH) but also for estimating the severity of PH by evaluating various morphological changes of the heart caused by pressure and volume overload and by ventricular interaction. We investigated whether a novel echocardiographic index, i.e., the ratio of the atrial areas (RA/LA), would be useful for evaluating the clinical status of patients with pulmonary arterial hypertension (PAH) treated with intravenous epoprostenol.

METHODS

We introduced epoprostenol therapy for seven PAH patients without severe tricuspid regurgitation. We evaluated clinical criteria indicative of prognosis, for example World Health Organization functional class (WHO-FC), brain natriuretic peptide (BNP) level, echocardiographic indices such as indexed RA area and RA/LA, and hemodynamics before and one year after intravenous epoprostenol therapy.

RESULTS

There were significant improvements in both RA/LA (2.5 ± 1.0, 1.3 ± 0.4, P < 0.001) and indexed RA area (22.5 ± 8.9, 14.5 ± 5.8, P < 0.001). The improvement in RA/LA was more sensitive than that in indexed RA area (P < 0.01). Moreover, RA/LA was significantly correlated with WHO-FC (r = 0.50, P < 0.01) and BNP level (r = 0.82, P < 0.01).

CONCLUSIONS

RA/LA is useful for evaluating the clinical status of patients with PAH treated with intravenous epoprostenol.

Long-term outcomes with ambrisentan monotherapy in pulmonary arterial hypertension

BACKGROUND

This study evaluated long-term outcomes in patients with pulmonary arterial hypertension (PAH) undergoing treatment with ambrisentan monotherapy, a selective oral endothelin-1 receptor antagonist.

METHODS AND RESULTS

Patients who participated in the Ambrisentan in Pulmonary Arterial Hypertension: A Phase 3, Randomized, Double-Blind, Placebo-Controlled Multicenter Efficacy Study (ARIES-1) clinical trial and extension phase at our institution were included. Cardiac catheterization, 6-minute walk distance (6MWD), and cardiac magnetic resonance (MRI) data were retrospectively reviewed. Twelve patients with PAH (11 idiopathic, 1 fenfluramine) had follow-up from 3 to 5.5 years from the initiation of ARIES-1. Patients received ambrisentan therapy throughout the study period and were on ambrisentan monotherapy for the first 2 years. At year 1, improvements in median mean pulmonary arterial pressure (PA), cardiac output, and pulmonary vascular resistance (PVR) were seen (P = .02, P = .03, P < .01), and the improvement in PVR persisted at 2 years. 6MWD also improved significantly between baseline (350 m) and 1 and 2 years (397 m, P < .01 and 393 m, P = .01). Cardiac MRI results were more varied, with an increase in RV ejection fraction from 29% at baseline to 46% at 2 years (P = .02), but other MRI variables did not improve.

CONCLUSIONS

Ambrisentan monotherapy led to improvements in catheterization, 6MWD, and RV ejection fraction, and shows promise as a long-term treatment for pulmonary arterial hypertension.

Evaluating health-related quality of life, work ability, and disability in pulmonary arterial hypertension: an unmet need

To our knowledge, there are no specific and validated measures of quality of life (QoL) or degree of disability for pulmonary arterial hypertension (PAH). A review of the literature shows that, with the exception of one recently designed specifically for pulmonary hypertension, QoL questionnaires used in PAH studies are generic measures. These are selected because of shared symptoms that do not necessarily correlate well with functional or physiologic measures and have not been validated for applicability in PAH. In this review, we present the available QoL tools for pulmonary artery hypertension and describe the need for more specific instruments that consider the physical and emotional implications of the diseases associated with PAH and the impact of various treatment options. We also discuss the impact of PAH on work ability and the need for provisions to address medical disability status and Social Security benefit status.

Diagnosis and assessment of pulmonary arterial hypertension

The diagnosis and assessment of pulmonary arterial hypertension is a rapidly evolving area, with changes occurring in the definition of the disease, screening and diagnostic techniques, and staging and follow-up assessment. The definition of pulmonary hypertension has been simplified, and is now based on currently available evidence. There has been substantial progress in advancing the imaging techniques and biomarkers used to screen patients for the disease and to follow up their response to therapy. The importance of accurate assessment of right ventricular function in following up the clinical course and response to therapy is more fully appreciated. As new therapies are developed for pulmonary arterial hypertension, screening, prompt diagnosis, and accurate assessment of disease severity become increasingly important. A clear definition of pulmonary hypertension and the development of a rational approach to diagnostic assessment and follow-up using both conventional and new tools will be essential to deriving maximal benefit from our expanding therapeutic armamentarium.

Beneficial and adverse effects of bosentan treatment in korean patients with pulmonary artery hypertension

Background and Objectives

The purpose of this study was to investigate 1) the beneficial effect of bosentan treatment (125 mg twice daily) on exercise capacity and echocardiographic variables and 2) the profiles and frequency of adverse events in Korean patients with World Health Organization (WHO) class III or IV pulmonary artery hypertension (PAH).

Subjects and Methods

Twelve patients who received bosentan treatment were investigated in an open label manner. One patient was excluded in the final analyses due to a prohibited concomitant medication. A 6-minute walk test and echocardiography were performed at baseline and after 12 weeks of treatment.

Results

The administration of bosentan for 12 weeks resulted in a significant improvement in exercise capacity (measured with the 6-minute walking distance), WHO functional capacity, and in echocardiographic variables. Bosentan treatment was associated with a decrease in the maximal tricuspid regurgitation jet velocity {from 4.7 m/sec (95% confidence interval, 3.89-5.45) at baseline to 4.4 m/sec (95% confidence interval, 3.61-5.1) at 12 weeks, p=0.03} and systolic pulmonary arterial pressure {from 105 mmHg (95% confidence interval, 74.4-135.6) at baseline to 93 mmHg (95% confidence interval, 66.3-120.1) at 12 weeks, p=0.04}. Treatment with bosentan at a dose of 125 mg twice a day was not associated with life-threatening side effects, although a higher incidence of elevated liver enzymes compared to previous studies was noted.

Conclusion

Bosentan at a dose of 125 mg twice daily is considered a clinically optimal, safe dose and can be used as a valuable treatment option in Korean PAH patients with WHO functional capacity III or IV, though close monitoring of liver function is required.

Tricuspid regurgitant jet velocity elevation and its relationship to lung function in pediatric sickle cell disease

Concerns about the morbidity and mortality associated with tricuspid regurgitant jet velocity (TRJV) elevation, which may indicate pulmonary hypertension (PHT), in adults with sickle cell disease (SCD) have prompted growing interest in screening the pediatric sickle cell population. The goals of our study were to estimate the prevalence of TRJV elevation and determine its relationship to pulmonary function in children and young adults with SCD at baseline. Seventy-eight subjects (10-24 years old) with SCD underwent prospective screening by Doppler echocardiogram (ECHO), complete lung function evaluation, and laboratory testing as part of standard care at steady state. Tricuspid regurgitation was quantifiable in 68/78 (87%) subjects and peak TRJV was > or =2.5 m/sec in 26/78 (33.3%) evaluated. The frequency of obstruction, restriction, or abnormal gas exchange found on lung function evaluation was not significantly different in subjects with and without TRJV elevation. However, significant inverse correlations were observed between TRJV and both % predicted forced vital capacity (FVC) (r = -0.29, P = 0.022) and oxygen saturation (r = -0.26, P = 0.036). When compared to subjects without TRJV elevation, subjects with TRJV elevation had significantly lower % predicted forced expiratory volume in 1 sec (FEV(1)) (78.9 +/- 14.4 vs. 86.6 +/- 13.0%, P = 0.023), FVC (82.8 +/- 14.1 vs. 90.7 +/- 12.9%, P = 0.017), and oxygen saturation (95.8 +/- 3.2 vs. 97.5 +/- 2.4%, P = 0.016). We found that the combination of low hemoglobin and low % predicted FVC best predicted TRJV elevation (chi(2) = 17.05, P = 0.001) in our cohort, correctly identifying 70% of cases and resulting in positive and negative predictive values of 60 and 74%, respectively. We conclude that in this young population with SCD, TRJV elevation that is not significantly associated with abnormal lung function is common at baseline.

Sildenafil monotherapy in portopulmonary hypertension can facilitate liver transplantation

Portopulmonary hypertension (POPH), or pulmonary arterial hypertension associated with cirrhosis, carries a high mortality and often precludes liver transplantation. Many POPH patients have preserved or increased cardiac output; therefore, decreasing pulmonary artery pressure rather than improving cardiac output is more important in reducing liver transplant risk, and this makes sildenafil an attractive therapeutic option. We assessed the clinical response of patients with POPH treated with sildenafil monotherapy. We retrospectively reviewed the charts of 10 patients with POPH and sildenafil monotherapy. Eight of 10 patients had hepatitis C virus infection. Patients took 31 +/- 14 mg (mean +/- standard deviation) thrice daily and were followed for 21 +/- 16 months. The World Health Organization functional class improved from 3.0 +/- 0.0 to 2.3 +/- 0.5 at 1 year (P < 0.05). Four of 8 patients increased the 6-minute walk distance at 1 year by 30 m or more. Three patients became transplant-eligible, 1 of whom underwent successful transplantation, and 3 patients have been stable without progression of liver disease or POPH. The remainder were not transplant candidates because of refractory POPH (n = 2) or other comorbidities (n = 2). We conclude that sildenafil may be an effective therapy for POPH that can stabilize or improve hemodynamics in patients with POPH and thereby facilitate liver transplantation.