Prognosis of Pulmonary Arterial Hypertension*

Clinical value of echocardiographic Doppler-derived right ventricular dp/dt in patients with pulmonary arterial hypertension

AIMS

Right ventricular (RV) dp/dt is the instantaneous rate of RV pressure rise during early systole and is a surrogate marker of RV contractility. The main objective of this study was to evaluate the ability of echocardiographic Doppler obtained RV dp/dt to predict long-term survival in patients with pulmonary arterial hypertension (PAH) and chronic thrombo-embolic pulmonary hypertension (CTEPH).

METHODS AND RESULTS

Seventy-eight consecutive newly diagnosed untreated patients (64 ± 15 years, 71% female, 57% PAH, 43% inoperable CTEPH) were included in the study. At baseline, patients were assessed clinically [New York Heart Association (NYHA) and 6 minutes walking distance (6MWD)], by transthoracic cardiac ultrasound and by right heart catherization. RV dp/dt was assessed using spectral Doppler recordings from the tricuspid regurgitation signal at a sweep speed of 200 mm/s by measuring the time interval in which the regurgitant velocity increased from 0.5 to 2 m/s. During a mean follow-up period of 3.5 ± 1.7 years, 31 patients died and 3 received a lung transplant [study endpoint reached in 34/78 (44%) patients]. The optimal RV dp/dt cut-off was determined by receiver operating characteristic analysis at 3 years to be 410 mmHg/s (specificity 84%, positive-predictive value 55%, and negative-predictive value 83%). In univariate analysis, RV dp/dt <410 mmHg/s (hazard ratio 2.67, 95% CI 1.30-5.47, P = 0.007), tricuspid annulus plane systolic excursion (TAPSE) <15 mm, NYHA, 6MWD, and right atrial pressure were predictors of mortality. In a multivariate model with TAPSE, RV dp/dt remained an independent predictor of mortality (P = 0.01).

CONCLUSION

A reduced baseline RV dp/dt is a clear indicator of poor outcome independent of TAPSE in patients with PAH/CTEPH.

Functional changes in pulmonary arterial endothelial cells associated with BMPR2 mutations

Pulmonary arterial hypertension (PAH) is a devastating disease characterized by abnormal remodeling of small, peripheral pulmonary arteries. Germline mutations in the bone morphogenetic protein receptor type 2 (BMPR2) gene are a major risk factor for developing PAH. At present, the correlation between the BMPR2 mutation and the patient's prognosis remains controversial despite several investigations. In this study, we explored the functional effects of four BMPR2 mutations to dissect the functional significance of the BMPR2 gene defect. Cellular immunofluorescence assay of four mutants (Tyr67Cys, Thr268fs, Ser863Asn, and Gln433X) revealed that the BMPR2 protein containing Thr268fs, Ser863Asn, or Gln433X exhibited abnormal subcellular localization. The BrdU incorporation and TUNEL assay suggested that any of the BMPR2 mutations Thr268fs, Ser863Asn, or Gln433X could improve endothelial cell apoptosis and decrease cell proliferation. All of the four mutants could inhibit nitric oxide (NO) synthesis in HLMVE cells, and ET-1 levels increased in the cells transfected with mutant Ser863Asn. Our results will improve the understanding of the genotype-phenotype correlations and mechanisms associated with BMPR2 mutations.

Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: Intensive care management of pulmonary hypertension

Pulmonary hypertension (PH) in the Intensive Care Unit (ICU) may be due to preexisting pulmonary vascular lung disease, liver disease, or cardiac diseases. PH also may be caused by critical illnesses, such as acute respiratory distress syndrome (ARDS), acute left ventricular dysfunction and pulmonary embolism, or may occur after cardiac or thoracic surgery.

Regardless of the underlying cause of PH, the final common pathway for hemodynamic deterioration and death is RV failure, which is the most challenging aspect of patient management. Therapy is thus aimed at acutely relieving RV overload by decreasing PVR and reversing RV failure with pulmonary vasodilators and inotropes.

Transition from prostacyclin analogue infusion to oral therapy in patients with pulmonary arterial hypertension: a 5-year follow-up

Transition from prostacyclin analogue infusion to oral therapy in patients with pulmonary arterial hypertension (PAH) is possible with acceptable short- and midterm results. However, there is a paucity of data on long-term outcomes after successful transition. Using a predefined protocol, transition to oral therapy was attempted in 22 patients with clinically stable PAH. Clinical and hemodynamic data were retrospectively collected at baseline as well as during and after transition. Parameters for successful versus nonsuccessful transition were also evaluated. All patients had severe PAH at baseline and showed clinical and hemodynamic improvement with prostacyclin analogue infusion. Initial oral agents used for transition were bosentan (63.6%), sildenafil (31.8%), and tadalafil (4.5%). Combination therapy was used in 68% of the patients. Successful transition was achieved in 11 patients (50%) with a mean transition duration of 16 months. After successful transition, clinical and hemodynamic parameters remained stable at midterm (mean, 18 months) and long-term (mean, 60 months) follow-up. Compared with the successful transition group, patients who experienced failure were older, had a higher frequency of idiopathic PAH, and had worse hemodynamic parameters during treatment with prostacyclin analogue alone, as well as during the transition period. In conclusion, successful transition from prostacyclin analogue infusion to oral therapy can be achieved in a significant proportion of patients with clinically stable PAH. After an initial successful transition, patients were able to maintain clinical and hemodynamic stability at the mid- and long-term follow-up.

Pulmonary arterial hypertension: challenges in translational research and a vision for change

Pulmonary arterial hypertension (PAH) is a vascular remodeling disease with a relentless course toward heart failure and early death. Existing PAH therapies, all of which were developed originally to treat systemic vascular diseases, cannot reverse the disease or markedly improve survival and are expensive. Although there has been a recent increase in the number of potential new therapies emerging from animal studies, less than 3% of the active PAH clinical trials are examining such therapies. There are many potential explanations for the translational gap in this complex multifactorial disease. We discuss these challenges and propose solutions that range from including clinical endpoints in animal studies and improving the rigor of human trials to conducting mechanistic early-phase trials and randomized trials with innovative designs based on personalized medicine principles. Global, independent patient and tissue registries and enhanced communication among academics, industry, and regulatory authorities are needed. The diversity of the mechanisms and pathology of PAH calls for broad comprehensive theories that encompass emerging evidence for contributions of metabolism and inflammation to PAH to support more effective therapeutic target identification.

Isolated right ventricular dysfunction in patients with human immunodeficiency virus

BACKGROUND

HIV-infected individuals are at increased risk for pulmonary hypertension and cardiomyopathy, portending a poor prognosis. Right ventricular (RV) dysfunction is associated with worse outcomes in these conditions, yet its prevalence is poorly defined in HIV. We sought to determine the prevalence of RV dysfunction in an outpatient HIV cohort.

METHODS

Echocardiograms were evaluated from 104 HIV-infected adults. Measurements included estimated pulmonary arterial systolic pressure (PASP) and several measures of RV function, including tricuspid annular plane systolic excursion (TAPSE), RV longitudinal myocardial strain (RVLMS), RV fractional area change (RVFAC), and myocardial performance index (MPI).

RESULTS

Sixteen subjects (15%) had PASP >35 mm Hg, yet RV function did not differ significantly from those with normal estimated PASP. RV dysfunction defined by RVFAC <35% occurred in 11%. RVLMS had a median value of -27.3%, and individuals below the median had lower TAPSE but no differences in left ventricular ejection fraction (LVEF), PASP, or other measures. Dyspnea was associated with the lowest quintile of RVLMS (≥-21.05%). There were 6 subjects with LVEF <50%, and these individuals had lower TAPSE but no differences in PASP or other RV functional measures.

CONCLUSIONS

RV dysfunction was common as estimated PASP >35 mm Hg and LV dysfunction, but these findings did not cosegregate. RV dysfunction in HIV-infected individuals may be a separate entity from LV/global cardiomyopathy or pulmonary hypertension and deserves further study.

Pulmonary hypertension after pneumonectomy for lung cancer

Background

We aimed to consolidate our clinical observations regarding the development of pulmonary hypertension following pneumonectomy for lung cancer.

Methods

Sixty-nine of 82 initially selected patients without pulmonary or cardiac comorbidities, who underwent pneumonectomy for lung cancer between October 2009 and October 2011, accomplished our protocol. Mean patient age was 60.6 years (range 44–78 years) and 10.1% were women.

Results

Postoperative complications occurred in 16 (23.2%) patients. Mortality at 1, 12, and 18 months postoperatively was 4.3%, 15.9%, and 29%, respectively. One year postoperatively, 37.9% of patients developed mild to moderate pulmonary hypertension and 3.4% had severe pulmonary hypertension. The calculated mean pulmonary artery systolic pressure at 1, 6, and 12 months postoperatively was 21.9 ± 6.6, 27.3 ± 9.3, and 34.1 ± 14 mm Hg, respectively ( p < 0.001). Receiver operating characteristic curve analysis showed a cutoff point at 35.5 mm Hg for late postoperative (at 12 months) pulmonary artery systolic pressure (sensitivity 80%, specificity 82%; p < 0.001) related to suboptimal clinical outcomes (decreased performance status or death), with a detected 18-fold risk for these patients ( p < 0.001).

Conclusions

Pulmonary hypertension may occur after pneumonectomy with its known adverse effects. Patients with late postoperative pulmonary artery systolic pressure > 35.5 mm Hg are at higher risk of a suboptimal clinical outcome.

Cystatin C: a potential biomarker for pulmonary arterial hypertension

BACKGROUND AND OBJECTIVE

Cystatin C (CysC), a novel marker of renal function, predicts left heart failure and cardiovascular mortality. The hypothesis that serum CysC levels correlate with right ventricular (RV) morphology, function and pressure in pulmonary arterial hypertension (PAH) was tested.

METHODS

As part of a prospective study, 14 PAH subjects and 10 matched controls underwent same-day echocardiography, cardiac magnetic resonance imaging (CMR), and phlebotomy for CysC, brain natriuretic peptide (BNP), and N-terminal BNP (NT-ProBNP). RV ejection fraction (RVEF), end-diastolic volume, end-systolic volume and mass were calculated using CMR. RV systolic pressure (RVSP), strain and diastolic function (including tricuspid valve (TV) E velocity, A velocity, e' velocity, E/A ratio and E/e' ratio) were assessed using echocardiography.

RESULTS

RVSP was significantly elevated in PAH subjects versus controls (57 ± 17 vs. 28 ± 8 mm Hg, P < 0.0001). CysC was abnormally elevated in the PAH cohort when compared with controls (1.00 ± 0.23 vs 0.78 ± 0.05 mg/L, P = 0.001). CysC positively correlated with RVSP (rho 0.61, P = 0.002), RV end-diastolic volume (rho 0.50, P = 0.01), RV end-systolic volume (rho 0.58, P = 0.003), mass index (rho 0.66, P = 0.0004), strain (rho 0.51, P = 0.01) and strain rate (rho 0.51, P = 0.01) and negatively correlated with RVEF (rho -0.58, P = 0.003) and TV e' (rho -0.75, P < 0.0001). The same correlations with BNP and NT-ProBNP were comparable with CysC.

CONCLUSIONS

In a small cohort, CysC accurately correlates with RV pressure, function and morphology. CysC may represent a novel PAH biomarker.

The effects of cyclic guanylate cyclase stimulation on right ventricular hypertrophy and failure alone and in combination with phosphodiesterase-5 inhibition

BACKGROUND

We investigated if soluble guanylate cyclase stimulation either alone or in combination with phosphodiesterase-5 (PDE5) inhibition could prevent pressure overload-induced right ventricular (RV) hypertrophy and failure.

METHODS

The soluble guanylate cyclase stimulator BAY 41-2272 (BAY, 10 mg · kg⁻¹ · d⁻¹) either alone or in combination (BAY + SIL) with a PDE5 inhibitor sildenafil (SIL, 100 mg · kg⁻¹ · d⁻¹) was examined for prevention of RV hypertrophy and failure in Wistar rats (n = 73) operated by pulmonary trunk banding.

RESULTS

All treatments failed to inhibit the development of RV hypertrophy and failure. In the BAY and BAY + SIL groups, there was an increased mortality. Mean arterial blood pressure was lowered and cardiac output increased in the BAY + SIL group. Systolic RV pressure was increased in the BAY and BAY + SIL groups possibly because of an inotropic response and/or increased venous return.

CONCLUSIONS

Stimulation of soluble guanylate cyclase by BAY 41-2272 alone or in combination with sildenafil failed to prevent the development of RV hypertrophy and failure in rats subjected to pulmonary trunk banding. An increased mortality was observed in animals treated by BAY 41-2272 alone and in combination with sildenafil.

Echocardiographic and hemodynamic predictors of mortality in idiopathic pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) can lead to the development of pulmonary hypertension, which is associated with an increased risk of death. In pulmonary arterial hypertension, survival is directly related to the capacity of the right ventricle to adapt to elevated pulmonary vascular load. The relative importance of right ventricular function in IPF is not well understood. Our objective was to evaluate right ventricular echocardiographic and hemodynamic predictors of mortality in a cohort of patients with IPF referred for lung transplant evaluation.

METHODS

We performed a retrospective cohort study of 135 patients who met 2011 American Thoracic Society/European Respiratory Society criteria for IPF and who were evaluated for lung transplantation at the Hospital of the University of Pennsylvania.

RESULTS

Right ventricle:left ventricle diameter ratio (hazard ratio [HR], 4.5; 95% CI, 1.7-11.9), moderate to severe right atrial and right ventricular dilation (HR, 2.9; 95% CI, 1.4-5.9; and HR, 2.7; 95% CI, 1.4-5.4, respectively) and right ventricular dysfunction (HR, 5.5; 95% CI, 2.6-11.5) were associated with an increased risk of death. Higher pulmonary vascular resistance was also associated with increased mortality (HR per 1 Wood unit, 1.3; 95% CI, 1.1-1.5). These risk factors were independent of age, sex, race, height, weight, FVC, and lung transplantation status. Other hemodynamic indices, such as mean pulmonary artery pressure and cardiac index, were not associated with outcome.

CONCLUSIONS

Right-sided heart size and right ventricular dysfunction measured by echocardiography and higher pulmonary vascular resistance by invasive hemodynamic assessment predict mortality in patients with IPF evaluated for lung transplantation.

Immunoglobulin G anti-endothelial cell antibodies: inducers of endothelial cell apoptosis in pulmonary arterial hypertension?

Endothelial cell (EC) apoptosis seems to play an important role in the pathophysiology of pulmonary arterial hypertension (PAH). We aimed to test the hypothesis that circulating anti-endothelial cell antibodies (AECA) of PAH patients induce EC apoptosis. Immunoglobulin (Ig)G was purified from sera of PAH patients (n = 26), patients with systemic lupus erythematosus (SLE) nephritis without PAH (n = 16), patients with systemic sclerosis (SSc) without PAH (n = 58) and healthy controls (n = 14). Human umbilical vein endothelial cells (HUVECs) were incubated with patient or healthy control IgG for 24 h. Thereafter, apoptosis was quantified by annexin A5 binding and hypoploid cell enumeration by flow cytometry. Furthermore, real-time cell electronic sensing (RT-CES™) technology was used to monitor the effects of purified IgG from patient and healthy control IgG on HUVECs. As demonstrated previously, IgG of AECA-positive SLE nephritis patients (n = 7) induced a higher percentage of apoptosis of HUVECs compared to IgG of AECA-negative SLE nephritis patients and healthy controls. Furthermore, IgG of AECA-positive SLE nephritis patients induced a marked decrease in cell index as assessed by RT-CES™ technology. IgG of AECA-positive PAH patients (n = 12) and SSc patients (n = 13) did not alter the percentage of HUVEC apoptosis or cell index compared to IgG of AECA-negative PAH and SSc patients and healthy controls. AECA-positive PAH patients, in contrast to SLE nephritis patients, do not have circulating IgG AECA that enhances apoptosis of HUVECs in vitro. Further studies should focus on other mechanisms by which AECA may enhance EC apoptosis in PAH, such as antibody-dependent cell-mediated cytotoxicity.

Four- and seven-year outcomes of patients with congenital heart disease-associated pulmonary arterial hypertension (from the REVEAL Registry)

Uncorrected congenital heart disease (CHD) frequently leads to pulmonary arterial hypertension (PAH), the most severe form of which is Eisenmenger syndrome (ES). We compared patients with idiopathic or heritable PAH (IPAH or HPAH; n = 1,626) against those with CHD-associated PAH (n = 353) who were enrolled in the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL Registry). Of patients with CHD-associated PAH, 151 had ES. Compared with the IPAH or HPAH cohort, the ES cohort had greater systemic blood flow (2 ± 1 vs 3 ± 2 L/min/m(2), p <0.001), lower mean right atrial pressure (10 ± 6 vs 7 ± 4 mm Hg, p <0.001), higher mean pulmonary artery pressure (53 ± 14 vs 65 ± 17 mm Hg, p <0.001), higher pulmonary vascular resistance index (22 ± 12 vs 32 ± 31 Wood units × m(2), p <0.001), and lower systemic arterial oxygen saturation at rest (92 ± 11% vs 84 ± 13%, p <0.001). At 4 years from enrollment and 7 years from diagnosis, survival rate was similar between IPAH or HPAH and CHD-associated PAH cohorts. For the overall CHD-associated PAH cohort, longer 6-minute walk distance, lower mean right atrial pressure, brain natriuretic peptide level <50 pg/ml, and the presence of acute vasoreactivity were predictors of survival at 4 years from enrollment; younger age and lower mean right atrial pressure were predictors of survival at 7 years from diagnosis. In conclusion, these observations support predicted physiologic differences (e.g., hemodynamics) between patients with IPAH or HPAH and patients with CHD-associated PAH, with or without a systemic-pulmonary shunt. These differences, however, did not translate into significantly improved 4- and 7-year survival rates in patients with ES versus IPAH or HPAH and CHD-associated PAH.

Shorter survival in familial versus idiopathic pulmonary arterial hypertension is associated with hemodynamic markers of impaired right ventricular function

Abstract Although individuals with familial pulmonary arterial hypertension (FPAH) have more severe hemodynamics, compared to individuals with idiopathic PAH (IPAH), it is unclear whether this translates into a survival difference. The influence of right ventricular (RV) function on survival in these groups is also unknown. We reviewed hemodynamic data and health information from a prospective institutional database of 57 FPAH and 66 IPAH patients registered with the Vanderbilt Pulmonary Hypertension Research Cohort. We compared hemodynamics at the time of diagnosis between the two groups and calculated pulmonary arteriolar capacitance (PC) and RV stroke work index (RVSWI). Using survival analysis, we compared freedom from a 5-year composite of death or lung transplantation in FPAH and IPAH patients. The composite outcome of death or transplant at 5 years from diagnosis was significantly increased in FPAH (log rank [Formula: see text]). PC and RVSWI were significantly decreased in FPAH, compared to IPAH ([Formula: see text] for both). In univariate analysis, PC (odds ratio [OR]: 0.17 [95% confidence interval (95% CI): 0.03-0.83]) and RVSWI (OR: 0.86 [95% CI: 0.77-0.95]) were predictors of mortality, as were cardiac index (OR: 0.17 [95% CI: 0.06-0.51]) and PVR (OR: 1.1 [95% CI: 1.01-1.12]). Among FPAH patients, RVSWI was lower in those who died or received a transplant than in survivors ([Formula: see text]), while PC was not ([Formula: see text]). We found significantly worse event-free survival and significantly lower PC and RVSWI in FPAH than in IPAH. In FPAH patients who died or underwent transplantation, RVSWI was lower than that in survivors, suggesting disproportionate RV dysfunction.

Evaluation of circulating proteins and hemodynamics towards predicting mortality in children with pulmonary arterial hypertension

BACKGROUND

Although many predictors have been evaluated, a set of strong independent prognostic mortality indicators has not been established in children with pediatric pulmonary arterial hypertension (PAH). The aim of this study was to identify a combination of clinical and molecular predictors of survival in PAH.

METHODS

This single-center, retrospective cohort study was performed from children with PAH between 2001 and 2008 at Children's Hospital Colorado. Blood samples from 83 patients (median age of 8.3 years-old) were obtained. We retrospectively analyzed 46 variables, which included 27 circulating proteins, 7 demographic variables and 12 hemodynamic and echocardiographic variables for establishing the best predictors of mortality. A data mining approach was utilized to evaluate predictor variables and to uncover complex data structures while performing variable selection in high dimensional problems.

RESULTS

Thirteen children (16%) died during follow-up (median; 3.1 years) and survival rates from time of sample collection at 1 year, 3 years and 5 years were 95%, 85% and 79%, respectively. A subset of potentially informative predictors were identified, the top four are listed here in order of importance: Tissue inhibitors of metalloproteinases-1 (TIMP-1), apolipoprotein-AI, RV/LV diastolic dimension ratio and age at diagnosis. In univariate analysis, TIMP-1 and apolipoprotein-AI had significant association with survival time (hazard ratio [95% confidence interval]: 1.25 [1.03, 1.51] and 0.70 [0.54-0.90], respectively). Patients grouped by TIMP-1 and apolipoprotein-AI values had significantly different survival risks (p<0.01).

CONCLUSION

Important predictors of mortality were identified from a large number of circulating proteins and clinical markers in this cohort. If confirmed in other populations, measurement of a subset of these predictors could aid in management of pediatric PAH by identifying patients at risk for death. These findings also further support a role for the clinical utility of measuring circulating proteins.

Genomics and proteomics of pulmonary vascular disease

Study of RNA and proteins in cells of both normal and diseased tissues is providing researchers with new knowledge of disease pathologies. While still in its early stages, high-throughput expression analysis is improving our understanding of the pathogenesis of pulmonary arterial hypertension (PAH). While many studies have used microarray and proteomic analyses as "hypothesis-generating" tools, the technologies also have potential to identify and quantify biomarkers of disease. To date, many of the published studies have examined gene expression profiles of tissue biopsies, others have utilized cells from peripheral blood. Microarray technology has been employed successfully in the investigation of a diverse array of human diseases. The potential of high-throughput expression analysis to improve our understanding of the pathogenesis of PAH is highlighted in this review. Proteomic studies of PAH and pulmonary vascular diseases in general have been little utilized thus far. To date, such studies are few and no consistent biomarker has emerged from studies of either plasma or blood cells from idiopathic pulmonary arterial hypertension (IPAH) patients. The studies of both lung tissue and lymphocytes are perhaps more revealing and suggest that changes in the cytoskeletal machinery may play a role in the pathogenesis of idiopathic pulmonary arterial hypertension. The oncology literature has demonstrated the utility of gene microarray analysis to predict important outcomes such as response to therapy and survival. It is likely that in the near future, gene microarrays and proteomic analyses will also be employed in a pharmacogenomics approach in PAH, helping to identify the most appropriate therapies for individual patients.

BIOMECHANICAL APPROACH TO THE CLINICAL TREATMENT OF PULMONARY ARTERIAL HYPERTENSION

Negative clinical trend of severe pulmonary arterial hypertension (PAH) is due to right ventricular chamber dilatation and consequent dysfunction. On a biomechanical basis the clinical evolution is associated to a progressive mismatching of the artero-ventricular junction and a possible mechanical intervention may be foreseen. This paper demonstrates how the progressive right ventricular dysfunction, in terms of biochemical–mechanical efficiency, is related to the stress–strain curve of the pulmonary artery, simulated by superimposing different elastance tubes in a cardiovascular mock. Applying the experimental signals to an "ideal" normal and dilated ventricle, it was demonstrated that the very high pulmonary elastance at high pressure is the prime cause of a sharp efficiency drop, in comparison with an aortic similar condition. This evidence supports the proposal of mechanical interventions to reduce pulmonary arterial elastance to improve the artero-ventricular matching, increase the reduced ventricular efficiency and change the negative trend of the illness.

TRPC4 inactivation confers a survival benefit in severe pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary arterial pressure with lumen-occluding neointimal and plexiform lesions. Activation of store-operated calcium entry channels promotes contraction and proliferation of lung vascular cells. TRPC4 is a ubiquitously expressed store-operated calcium entry channel, but its role in PAH is unknown. We tested the hypothesis that TRPC4 promotes pulmonary arterial constriction and occlusive remodeling, leading to right ventricular failure in severe PAH. Severe PAH was induced in Sprague-Dawley rats and in wild-type and TRPC4-knockout Fischer 344 rats by a single subcutaneous injection of SU5416 [SU (semaxanib)], followed by hypoxia exposure (Hx; 10% O2) for 3 weeks and then a return to normoxia (Nx; 21% O2) for 3 to 10 additional weeks (SU/Hx/Nx). Although rats of both backgrounds exhibited indistinguishable pulmonary hypertensive responses to SU/Hx/Nx, Fischer 344 rats died within 6 to 8 weeks. Normoxic and hypertensive TRPC4-knockout rats recorded hemodynamic parameters similar to those of their wild-type littermates. However, TRPC4 inactivation conferred a striking survival benefit, due in part to preservation of cardiac output. Histological grading of vascular lesions revealed a reduction in the density of severely occluded small pulmonary arteries and in the number of plexiform lesions in TRPC4-knockout rats. TRPC4 inactivation therefore provides a survival benefit in severe PAH, associated with a decrease in the magnitude of occlusive remodeling.

Predictors of diastolic-to-wedge gradient in patients evaluated for pulmonary hypertension

Background

Differentiation of pulmonary arterial hypertension (PAH) and pulmonary venous hypertension (PVH) often requires right heart catheterization (RHC). We sought to determine whether a combination of clinical and echocardiographic variables could predict the pulmonary diastolic to wedge (PAd-PWP) gradient and thus differentiate patients with PAH and PVH.

Methods

We prospectively enrolled 108 patients presenting for PH evaluation. We developed a multivariate model to predict PAd-PWP gradient and validated this model using bootstrapping technique.

Results

PAH patients had worse hemodynamics and were more likely to have evidence of right ventricular dilation and dysfunction whereas patients with PVH were older and more likely to have features of the metabolic syndrome. PAd-PWP gradient of ≥ 6mmHg accurately discriminated patients with PAH compared to PVH. Our model including clinical and echocardiographic variables was highly accurate for the prediction of PAd-PWP gradient with a slope 0.89 (slope of 1 represents perfect prediction).

Conclusions

In this prospective study of patients referred for PH evaluation, a model of readily available clinical parameters and simple echocardiographic measurements accurately predicted the PAd-PWP gradient, allowing discrimination of patients with PAH and PVH. This model requires validation in a larger cohort, but may afford clinicians more parsimony with referral for invasive testing in the evaluation of PH.

Pulmonary arterial hypertension in SLE: what do we know?

Pulmonary hypertension (PH) can occur at any time during the course of systemic lupus erythematosus (SLE), and can be independent of lupus disease activity in other systems. The pathogenesis of PH in SLE can be multifactorial, but pulmonary arterial hypertension (PAH) is the commonest cause of PH in SLE. The international PH registries have published that approximately 15% of connective tissue disease-associated PH is lupus related in their cohorts. As the symptoms of PH in SLE can be mild and non-specific in early stages, an increasing awareness of this devastating complication is essential for early diagnosis. Echocardiographic evaluation of several right heart variables in addition to systolic pulmonary artery pressure estimation reduces false positive rates for PH detection. Antiphospholipid antibodies may predict SLE-PAH. Prompt treatment of PAH with newer PAH therapy as well as immunosuppression can reduce morbidity and prolong survival. The survival in SLE-associated PAH is better compared with systemic sclerosis-associated PH but worse than idiopathic PAH. Pregnancy in SLE-PAH can result in a fatal outcome, especially in severe and poorly controlled PH at onset.

Comorbid conditions and outcomes in patients with pulmonary arterial hypertension: a REVEAL registry analysis

BACKGROUND

Comorbidities can affect disease progression and/or response to treatment in various conditions. Comorbid conditions are prevalent in patients with pulmonary arterial hypertension (PAH); however, their effect on patient outcomes remains unknown.

METHODS

We evaluated the effect on functional class (FC), 6-min walk test distance (6MWD), and survival of the seven most common, comorbid conditions at enrollment in patients with PAH from the Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL Registry): hypertension, clinical depression, type 2 diabetes mellitus (diabetes), obesity, COPD, sleep apnea, and thyroid disease.

RESULTS

Patients with COPD or diabetes had the shortest 6MWD at enrollment (304.5 and 304.6 m, respectively) vs other comorbidities. Adjusted linear regression for 6MWD at enrollment revealed significant reductions among patients who were hypertensive, obese, diabetic, or had COPD (P<.001). A larger proportion of patients who were obese or had COPD were FC III/IV vs FC I/II at enrollment (P<.001). There was a greater risk for death among patients with diabetes (hazard ratio [HR], 1.73; 95% CI, 1.40-2.13; P<.001) or COPD (HR, 1.59; 95% CI, 1.34-1.90; P<.001), but there was a reduced risk for death in patients who were obese (HR, 0.73; 95% CI, 0.61-0.86; P<.001).

CONCLUSIONS

Compared with other analyzed comorbidities in patients with PAH, hypertension, obesity, diabetes, and COPD were associated with significantly worse 6MWD; obesity and COPD were associated with worse FC; and diabetes and COPD were associated with increased risk for death. Further investigation of the effects of treating these comorbidities in patients with PAH is warranted.

TRIAL REGISTRY

ClinicalTrials.gov; Identifier: NCT00370214; URL: www.clinicaltrials.gov.

A simple echocardiographic method to estimate pulmonary vascular resistance

Pulmonary hypertension includes heterogeneous diagnoses with distinct hemodynamic pathophysiologic features. Identifying elevated pulmonary vascular resistance (PVR) is critical for appropriate treatment. We reviewed data from patients seen at referral pulmonary hypertension clinics who had undergone echocardiography and right-side cardiac catheterization within 1 year. We derived equations to estimate PVR using the ratio of estimated pulmonary artery (PA) systolic pressure (PASPDoppler) to right ventricular outflow tract velocity time integral (VTI). We validated these equations in a separate sample and compared them with a published model based on the ratio of the transtricuspid flow velocity to right ventricular outflow tract VTI (model 1, Abbas et al 2003). The derived models were as follows: PVR = 1.2 × (PASP/right ventricular outflow tract VTI) (model 2) and PVR = (PASP/right ventricular outflow tract VTI) + 3 if notch present (model 3). The cohort included 217 patients with mean PA pressure of 45.3 ± 11.9 mm Hg, PVR of 7.3 ± 5.0 WU, and PA wedge pressure of 14.8 ± 8.1 mm Hg. Just >1/3 had a PA wedge pressure >15 mm Hg (35.5%) and 82.0% had PVR >3 WU. Model 1 systematically underestimated catheterization estimated PVR, especially for those with high PVR. The derived models demonstrated no systematic bias. Model 3 correlated best with PVR (r = 0.80 vs r = 0.73 and r = 0.77 for models 1 and 2, respectively). Model 3 had superior discriminatory power for PVR >3 WU (area under the curve 0.946) and PVR >5 WU (area under the curve 0.924), although all models discriminated well. Model 3-estimated PVR >3 was 98.3% sensitive and 61.1% specific for PVR >3 WU (positive predictive value 93%; negative predictive value 88%). In conclusion, we present an equation to estimate the PVR, using the ratio of PASPDoppler to right ventricular outflow tract VTI and a constant designating presence of right ventricular outflow tract VTI midsystolic notching, which provides superior agreement with catheterization estimates of PVR across a wide range of values.

Prognostic significance of six-minute walk test in non-group 1 pulmonary hypertension

OBJECTIVE

To assess the value of the six-minute walk test (6MWT) to predict outcome in non-group 1 pulmonary hypertension (PH).

BACKGROUND

Distance walked during 6MWT has been widely used as a prognostic test in pulmonary arterial hypertension (group 1 pulmonary hypertension); however, little is known regarding its prognostic value in other groups of PH.

METHODS

This was a retrospective study of 60 patients diagnosed of PH, Dana Point classification groups 2-5. 6MWT and echocardiography were performed in all cases.

RESULTS

Forty patients (66.6%) were females. Mean age was 70.8 ± 10.7 years (range: 32-85). Seven patients died after a mean follow-up of 23.2 ± 16.7 months. Distance <400 m during 6MWT was associated with a higher risk for death (RR: 4.39; 95% CI: 1.13-17.05; p = 0.03) and for clinical deterioration (death or need for hospitalization) (RR: 2.76; 95% CI: 1.18-6.42; p = 0.02).

CONCLUSIONS

6MWT is useful to predict outcome in non-group 1 PH.

Increased pulmonary artery diameter on chest computed tomography can predict borderline pulmonary hypertension

Pulmonary hypertension (PH) often leads to dilatation of the pulmonary artery (PA), which can be measured on chest computed tomography (CT). While the predictive capability of PA dilatation is useful to distinguish PH (mean PA pressure ≥25 mmHg) from normal (mean PA pressure ≤ 20 mmHg), CT characteristics of borderline PH (mean PA pressure 21-24 mmHg) have not been described. We aimed to investigate whether patients with borderline PH already show PA dilatation and to assess the diagnostic accuracy of PA dilatation for borderline PH diagnosis. Between April 2003 and September 2008, consecutive symptomatic patients with a mean PA pressure below 25 mmHg on right heart catheterization who had a chest CT available were retrospectively included. PA diameters from chest CT were correlated with hemodynamic measurements and analyzed with respect to their accuracy of predicting borderline PH. Main PA diameters were significantly larger in 26 patients with borderline PH compared with 52 patients without PH (3.16 ± 0.53 vs. 2.78 ± 0.43 cm, P = 0.001). The main PA diameter on CT correlated with mean PA pressure (r = 0.496, P < 0.001) and pulmonary vascular resistance (r = 0.445, P < 0.001), and predicted borderline PH with sensitivity, specificity, negative and positive predictive values of 77%, 62%, 84%, and 50%, respectively, using a cutoff ≥2.9 cm. This first systematic investigation of CT parameters in symptomatic patients with mean PA pressures less than 25 mmHg could show that, even in patients with borderline PH, significant PA dilatation can be present, which was related to PA pressure and pulmonary vascular resistance. This can be useful for identification of patients with borderline PH for further study and to prompt further diagnostic work-up of possible underlying diseases.

Pulmonary arterial hypertension: use of delayed contrast-enhanced cardiovascular magnetic resonance in risk assessment

Background

Pulmonary arterial hypertension is a severe and progressive disease. Its early diagnosis is the greatest clinical challenge.

Objective

To evaluate the presence and extension of the delayed myocardial contrast-enhanced cardiovascular magnetic resonance, as well as to verify if the percentage of the myocardial fibrosis mass is a severity predictor.

Methods

Cross-sectional study with 30 patients with pulmonary arterial hypertension of groups I and IV, subjected to clinical, functional and hemodynamic evaluation, and to cardiac magnetic resonance.

Results

The mean age of patients was 52 years old, with female predominance (77%). Among the patients, 53% had right ventricular failure at diagnosis, and 90% were in functional class II/III. The mean of the 6-minute walk test was 395m. In hemodynamic study with right catheterism, the mean average pulmonary arterial pressure was 53.3mmHg, of the cardiac index of 2.1L/ min.m², and median right atrial pressure was 13.5 mmHg. Delayed myocardial contrast enhanced cardiovascular magnetic resonance was found in 28 patients. The mean fibrosis mass was 9.9 g and the median percentage of fibrosis mass was 6.17%. The presence of functional class IV, right ventricular failure at diagnosis, 6-minute walk test < 300 meters and right atrial pressure ≥ 15 mmHg, with cardiac index < 2.0 L/ min.m², there was a relevant association with the increased percentage of myocardial fibrosis.

Conclusion

The percentage of the myocardial fibrosis mass indicates a non-invasive marker with promising perspectives in identifying patients with high risk factors for pulmonary hypertension.

The impact of right ventricular stroke work on B-type natriuretic peptide levels in patients with mitral stenosis undergoing percutaneous mitral valvuloplasty

OBJECTIVES

We aimed to explore the relationship between brain natriuretic peptide (BNP) levels and right ventricular (RV) function in patients with mitral stenosis (MS), and to investigate the hemodynamic parameters that predict reduction of BNP levels after percutaneous mitral valvuloplasty (PMV).

BACKGROUND

Few studies have evaluated BNP in the context of MS, specifically the impact of the RV stroke work (RVSW) on serum BNP levels has not been defined.

METHODS

Thirty patients with symptomatic rheumatic MS in sinus rhythm who were referred for a PMV were enrolled. Right and left heart pressures were obtained before and after valvuloplasty. RVSW index (RVSWI) was calculated by cardiac catheterization.

RESULTS

Basal BNP levels were elevated in MS patients and correlated with several hemodynamic parameters including pulmonary pressure, pulmonary vascular resistance index, cardiac index (CI), and RVSWI. In multivariate analysis, CI and RVSWI were independent predictors of raised basal BNP levels. PMV resulted in a significant decrease in the RVSWI with a concurrent increase in CI (2.4 ± 0.43 to 2.9 ± 0.8 L/min/m(2), P = 0.010). Overall, plasma BNP levels significantly decreased from 124 (63/234) to 73 (48/148) pg/ml postvalvuloplasty. Multivariate analysis revealed that the reduction of left atrial (LA) pressure post-PMV was an independent predictor of change in BNP levels.

CONCLUSIONS

Elevated baseline BNP level in MS patients was independently associated with CI and RVSWI. Plasma BNP levels were reduced after successful PMV, which was associated with the reduction of the LA pressure.

Pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a chronic and progressive disease leading to right heart failure and ultimately death if untreated. The first classification of PH was proposed in 1973. In 2008, the fourth World Symposium on PH held in Dana Point (California, USA) revised previous classifications. Currently, PH is devided into five subgroups. Group 1 includes patients suffering from idiopathic or familial PAH with or without germline mutations. Patients with a diagnosis of PAH should systematically been screened regarding to underlying mutations of BMPR2 gene (bone morphogenetic protein receptor type 2) or more rarely of ACVRL1 (activine receptor-like kinase type 1), ENG (endogline) or Smad8 genes. Pulmonary veno occusive disease and pulmonary capillary hemagiomatosis are individualized and designated as clinical group 1'. Group 2 'Pulmonary hypertension due to left heart diseases' is divided into three sub-groups: systolic dysfonction, diastolic dysfonction and valvular dysfonction. Group 3 'Pulmonary hypertension due to respiratory diseases' includes a heterogenous subgroup of respiratory diseases like PH due to pulmonary fibrosis, COPD, lung emphysema or interstitial lung disease for exemple. Group 4 includes chronic thromboembolic pulmonary hypertension without any distinction of proximal or distal forms. Group 5 regroup PH patients with unclear multifactorial mechanisms. Invasive hemodynamic assessment with right heart catheterization is requested to confirm the definite diagnosis of PH showing a resting mean pulmonary artery pressure (mPAP) of ≥ 25 mmHg and a normal pulmonary capillary wedge pressure (PCWP) of ≤ 15 mmHg. The assessment of PCWP may allow the distinction between pre-capillary and post-capillary PH (PCWP > 15 mmHg). Echocardiography is an important tool in the management of patients with underlying suspicion of PH. The European Society of Cardiology and the European Respiratory Society (ESC-ERS) guidelines specify its role, essentially in the screening proposing criteria for estimating the presence of PH mainly based on tricuspid regurgitation peak velocity and systolic artery pressure (sPAP). The therapy of PAH consists of non-specific drugs including oral anticoagulation and diuretics as well as PAH specific therapy. Diuretics are one of the most important treatment in the setting of PH because right heart failure leads to fluid retention, hepatic congestion, ascites and peripheral edema. Current recommendations propose oral anticoagulation aiming for targeting an International Normalized Ratio (INR) between 1.5-2.5. Target INR for patients displaying chronic thromboembolic PH is between 2–3. Better understanding in pathophysiological mechanisms of PH over the past quarter of a century has led to the development of medical therapeutics, even though no cure for PAH exists. Several specific therapeutic agents were developed for the medical management of PAH including prostanoids (epoprostenol, trepoprostenil, iloprost), endothelin receptor antagonists (bosentan, ambrisentan) and phosphodiesterase type 5 inhibitors (sildenafil, tadalafil). This review discusses the current state of art regarding to epidemiologic aspects of PH, diagnostic approaches and the current classification of PH. In addition, currently available specific PAH therapy is discussed as well as future treatments.

Screening and treating pulmonary arterial hypertension in a tertiary hospital-based multidisciplinary clinic: the first 200 patients

BACKGROUND

Pulmonary arterial hypertension (PAH) is an increasingly recognised serious illness with insidious onset, delayed diagnosis, complex diagnostic algorithms and poor prognosis, but with recently available effective treatments.

AIMS

To efficiently diagnose and to offer treatment for PAH, we established a multidisciplinary service in 2005, where patients attend a clinic staffed by specialists in cardiology, respiratory medicine, rheumatology and immunology in a tertiary referral hospital setting.

METHODS

We studied the first 200 patients referred. Serology, echocardiography, lung function tests, high-resolution computed tomography, World Health Organisation Class determination and 6-min walk tests and/or right heart catheterisation were performed, as clinically indicated.

RESULTS

Of the 200 patients seen, 66 had confirmed pulmonary hypertension (mean pulmonary artery pressure > 25 mmHg) diagnosed on echocardiography ± right heart catheterisation. Of these patients, 58 had catheter-proven PAH (mean pulmonary artery pressure > 25 mmHg with mean wedge pressure < 15 mmHg). Underlying diagnoses for the confirmed PAH patients were idiopathic (32), scleroderma-associated (14), other connective tissue disease (4) and associated with congenital heart disease (8). Patients with confirmed PAH were commenced on PAH-specific therapy--initially bosentan in the majority but sildenafil, and iloprost were occasionally used initially for patient-specific reasons. Median time from when the patient first called the clinic to prescription of therapy was 16 days (interquartile range; 0-31 days). All surviving patients with PAH have attended for regular 6-monthly follow-up visits with a 100% retention rate up to 4 years.

CONCLUSION

A multidisciplinary clinic can provide efficient diagnosis and rapid triage to PAH-specific therapy, if appropriate. Retention rates remain high, at follow up.

Benefits of intensive treadmill exercise training on cardiorespiratory function and quality of life in patients with pulmonary hypertension

BACKGROUND

Pulmonary hypertension (PH) restricts the ability to engage in physical activity and decreases longevity. We examined the impact of aerobic exercise training on function and quality of life in patients with World Health Organization group 1 PH.

METHODS

Patients were randomized to a 10-week education only (EDU) or education/exercise combined (EXE) group. The exercise program consisted of 24-30 sessions of treadmill walking for 30-45 min per session at 70% to 80% of heart rate reserve. Outcome variables included changes in 6-min walk test (6MWT) distance, time to exercise intolerance, peak work rate (WR) from a cardiopulmonary treadmill test, and quality-of-life measures, including the Short Form Health Survey, version 2 (SF-36v2) and Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR).

RESULTS

Data are presented as mean SD. Twenty-three women (age, 54 11 years; BMI, 31 7 kg/m 2 ) were randomized to the EDU (n 5 13) or EXE (n 5 10) groups. Following 10 weeks of intervention, patients in the EXE group demonstrated an improvement in 6MWT distance (56 45 m; P 5 .002), increased time to exercise intolerance (1.9 1.3 min; P 5 .001), and peak WR (26 23 W; P 5 .004). Additionally, the EXE group scored significantly ( P , .050) better on six of the eight scales on SF-36v2, and fi ve of the six scales on CAMPHOR. In contrast, no significant improvement was observed for any of the outcome measures following EDU. No adverse events were noted in either group.

CONCLUSION

Ten weeks of brisk treadmill walking improved 6MWT distance, cardiorespiratory function, and patient-reported quality of life in female patients with group 1 PH.

Impaired left ventricular mechanics in pulmonary arterial hypertension: identification of a cohort at high risk

BACKGROUND

Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling and right heart failure. The right (RV) and left ventricles (LV) do not function in isolation, sharing a common pericardial sac and interventricular septum. We sought to define the clinical and prognostic significance of ventricular interdependence in PAH and its association with LV filling patterns through speckle-tracking strain echocardiography.

METHODS AND RESULTS

Echocardiography was performed in 71 adults with a new diagnosis of PAH. To analyze LV and RV function separately, we measured peak systolic longitudinal and circumferential strain of the LV and RV. Survival was assessed >2 years. Patients had dilated right-sided chambers (right atrial volume index, 44 ± 19 mL/m(2); RV end-diastolic area, 34 ± 9 cm(2)), and reduced RV function (RV fractional area change, 28 ± 12%). Speckle-tracking echocardiography revealed significant reductions in RV free wall peak systolic strain (-15 ± 3%). Despite normal LV size and normal conventional measures of LV systolic function (end-diastolic dimension, 42 ± 6 mm; ejection fraction, 65 ± 8%; cardiac index, 2.6 ± 0.8 L/min per m(2)), patients had reduced LV free wall systolic strain (-15 ± 3%). Decreased LV free wall systolic strain was associated with a delayed relaxation mitral inflow Doppler pattern, P=0.0002. During 2-year follow-up, 19 patients (27%) died. LV strain was associated with increased mortality (unadjusted hazard ratio, 2.40 per 5% decrease in LV free wall strain, 1.22-4.68), which remained significant when adjusted for age, sex, World Health Organization functional class, and PAH pathogenesis (hazard ratio, 3.11, 1.38-7.20).

CONCLUSIONS

The pressure loading in PAH results in geometric alterations and functional decline of the RV, with marked reduction in RV systolic strain. Despite preservation of LV ejection fraction, LV systolic strain was also reduced and associated with early mortality, highlighting the significance of ventricular interdependence in PAH.

Human immunodeficiency virus-1 transgene expression increases pulmonary vascular resistance and exacerbates hypoxia-induced pulmonary hypertension development

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by increased pulmonary arterial resistance and vessel remodeling. Patients living with human immunodeficiency virus-1 (HIV-1) have an increased susceptibility to develop severe pulmonary hypertension (PH) irrespective of their CD4+ lymphocyte counts. While the underlying cause of HIV-PAH remains unknown, the interaction of HIV-1 proteins with the vascular endothelium may play a critical role in HIV-PAH development. Hypoxia promotes PH in experimental models and in humans, but the impact of HIV-1 proteins on hypoxia-induced pulmonary vascular dysfunction and PAH has not been examined. Therefore, we hypothesize that the presence of HIV-1 proteins and hypoxia synergistically augment the development of pulmonary vascular dysfunction and PH. We examined the effect of HIV-1 proteins on pulmonary vascular resistance by measuring pressure-volume relationships in isolated lungs from wild-type (WT) and HIV-1 Transgenic (Tg) rats. WT and HIV-1 Tg rats were exposed to 10% O₂ for four weeks to induce experimental pulmonary hypertension to assess whether HIV-1 protein expression would impact the development of hypoxia-induced PH. Our results demonstrate that HIV-1 protein expression significantly increased pulmonary vascular resistance (PVR). HIV-1 Tg mice demonstrated exaggerated pulmonary vascular responses to hypoxia as evidenced by greater increases in right ventricular systolic pressures, right ventricular hypertrophy and vessel muscularization when compared to wild-type controls. This enhanced PH was associated with enhanced expression of HIF-1α and PCNA. In addition, in vitro studies reveal that medium from HIV-infected monocyte derived macrophages (MDM) potentiates hypoxia-induced pulmonary artery endothelial proliferation. These results indicate that the presence of HIV-1 proteins likely impact pulmonary vascular resistance and exacerbate hypoxia-induced PH.

Managing pulmonary arterial hypertension and optimizing treatment options: prognosis of pulmonary artery hypertension

Survival in patients with pulmonary artery hypertension has improved, but outcomes are still suboptimal. Therapeutic focus must shift from short-term functional changes to improvements in long-term outcomes. Several outcome predictors, both at baseline and on therapy, offer guidance for clinicians treating pulmonary artery hypertension.

Dehydroepiandrosterone restores right ventricular structure and function in rats with severe pulmonary arterial hypertension

Current therapy of pulmonary arterial hypertension (PAH) is inadequate. Dehydroepiandrosterone (DHEA) effectively treats experimental pulmonary hypertension in chronically hypoxic and monocrotaline-injected rats. Contrary to these animal models, SU5416/hypoxia/normoxia-exposed rats develop a more severe form of occlusive pulmonary arteriopathy and right ventricular (RV) dysfunction that is indistinguishable from the human disorder. Thus, we tested the effects of DHEA treatment on PAH and RV structure and function in this model. Chronic (5 wk) DHEA treatment significantly, but moderately, reduced the severely elevated RV systolic pressure. In contrast, it restored the impaired cardiac index to normal levels, resulting in an improved cardiac function, as assessed by echocardiography. Moreover, DHEA treatment inhibited RV capillary rarefaction, apoptosis, fibrosis, and oxidative stress. The steroid decreased NADPH levels in the RV. As a result, the reduced reactive oxygen species production in the RV of these rats was reversed by NADPH supplementation. Mechanistically, DHEA reduced the expression and activity of Rho kinases in the RV, which was associated with the inhibition of cardiac remodeling-related transcription factors STAT3 and NFATc3. These results show that DHEA treatment slowed the progression of severe PAH in SU5416/hypoxia/normoxia-exposed rats and protected the RV against apoptosis and fibrosis, thus preserving its contractile function. The antioxidant activity of DHEA, by depleting NADPH, plays a central role in these cardioprotective effects.

Noninvasive assessment of right heart function and hemodynamics during exercise in patients with pulmonary arterial hypertension

OBJECTIVES

Noninvasive assessment of right heart function and hemodynamics in patients with pulmonary arterial hypertension (PAH) is most often performed at rest, whereas the symptoms, in general, present with exertion. Assessment during exertion is limited to symptom assessment and the 6-minute walk distance. We investigated the feasibility of obtaining echocardiographic data that could accurately reflect pulmonary artery pressures (PAP), particularly mean PAP and right ventricular function during exercise in patients with PAH.

METHODS

We investigated right ventricular function and hemodynamics using echocardiography during symptom-limited exercise in 10 consecutive patients undergoing right heart catheterization (RHC) as part of their clinical evaluation for PAH. We further assessed these measurements for correlation with known predictors of outcome in PAH in an exploratory analysis.

RESULTS

We were able to successfully obtain complete right heart measurements by echocardiography, including mean PAP, in the majority (9 of 10) of the subjects. One patient had an incomplete tricuspid regurgitation jet at rest and with exercise. Echocardiographic pulmonary vascular resistance correlated with RHC cardiac output and brain natriuretic peptide level, whereas tricuspid annular plane systolic excursion during exercise correlated with right atrial pressure on RHC, brain natriuretic peptide, and 6-minute walk distance. Tricuspid regurgitation velocity and mean PAP with exercise correlated moderately with mean PAP and cardiac output by RHC.

CONCLUSIONS

Exercise echocardiography can provide meaningful data in patients with PAH, including measuring mean PAP. The presence of correlations in this small number of patients indicates promising targets for future investigation.

[Ventricular septal defects in adults: 15 years of surgical experience in a single Colombian cardiovascular center]

OBJECTIVE

To review the surgical experience with ventricular septal defects in adults in Colombia.

METHOD

Descriptive, retrospective study of surgically repaired patients between 1995 and 2010. Clinical, echocardiographic, hemodynamic, and surgical findings were related to hospital and outpatient outcomes.

RESULTS

Fifty-two patients were analyzed (mean age 29.3 ± 9.9 years, 54% women). Ventricular septal defects were classified, according to the Society of Thoracic Surgeons, as type 2 (membranous, 84.6%), type 1 (subarterial, 13.5%), and type 3 (inlet, 1.9%). Dyspnea, Qp/Qs ≥ 2, and pulmonary hypertension were the most common indications for surgery. No peri-operative deaths were found. Outpatient mean follow-up was 2.7 ± 3.6 years and was possible for 90% of the original cohort and late mortality was 5% (one case). Despite that residual ventricular septal defects (29%) were frequent, no patient required surgical re-intervention for this reason. Improvements in functional class and pulmonary artery systolic pressure were also observed.

CONCLUSIONS

Surgical closure of ventricular septal defects in adults is a safe procedure without early mortality and a low complications index. Residual ventricular septal defects underline the need for life-long follow-up.

Effect of aerobic exercise training on fatigue and physical activity in patients with pulmonary arterial hypertension

OBJECTIVE

To investigate the effectiveness of an exercise intervention for decreasing fatigue severity and increasing physical activity in individuals with pulmonary arterial hypertension (PAH). A small, phase 2 randomized clinical trial of the effect of aerobic exercise training on fatigue severity and physical activity in patients with idiopathic or PAH associated with other conditions was conducted.

METHODS

Twenty-four patients with PAH (24 female; age: 54.4 ± 10.4 years; BMI: 30.8 ± 7.2 kg/m(2)) participated in the study. A convenience sample was recruited in which 9% (28 of 303) of screened patients were enrolled. The project was carried out in a clinical pulmonary rehabilitation clinic during existing pulmonary rehabilitation program sessions. Patients with PH were randomized into a 10-week program that consisted of patient education only or patient education plus an aerobic exercise-training regimen. Both groups received 20 lectures, two per week over the 10-weeks, on topics related to PAH and its management. The aerobic exercise training consisted of 24-30 sessions of treadmill walking for 30-45 min per session at an intensity of 70-80% of heart rate reserve, three days per week over the 10 weeks.

RESULTS

After 10-weeks of intervention, patients receiving aerobic exercise training plus education reported routinely engaging in higher levels of physical activity (p < 0.05) and a decrease in fatigue severity (p = 0.03). Patients in the education only group did not report changes in fatigue severity or participation in physical activity.

CONCLUSIONS

The 10-week aerobic exercise training intervention resulted in increased physical activity and decreased fatigue in individuals with PAH. ClinicalTrials.gov Identifier: NCT00678821.

Dispersion durations of P-wave and QT interval in children with congenital heart disease and pulmonary arterial hypertension

This study aimed to investigate homogeneity disorders of ventricular repolarization and atrial conduction via QT dispersion and P-wave dispersion in children with congenital heart disease (CHD) and pulmonary arterial hypertension (PAH). Three groups of 20 each were generated and involved in this study. The first group included 20 children with both CHD and PAH. The second group consisted of 20 children with CHD but no PAH, and the third group was composed of 20 age- and sex-matched healthy children. Electrocardiographic records were used to determine P-wave, QT, and corrected QT (QTc) dispersions. The pulmonary hypertension group compared with the group having no pulmonary hypertension and the control group showed a significantly longer P-wave dispersion duration (39.10 ± 9.54 vs. 26.30 ± 4.99 ms, p < 0.001; and 24.80 ± 6.94 ms, p < 0.001, respectively) and QT dispersion duration (52.80 ± 15.11 vs. 37.60 ± 6.00 ms, p < 0.001; and 35.00 ± 7.77 ms, p < 0.001, respectively). In addition, the durations of maximum QTc and QTc dispersion were significantly longer in pulmonary hypertension group than in the other two groups. The risk of atrial and ventricular arrhythmia was found to be increased in the patients with both CHD and PAH. Physicians should pay close attention to possible atrial and ventricular arrhythmias during the treatment and follow-up evaluation of these patients.