Abstract: Background—Novel therapies have recently become available for pulmonary arterial hypertension. We conducted a study to characterize mortality in a multicenter prospective cohort of patients diagnosed with idiopathic, familial, or anorexigen-associated pulmonary arterial hypertension in the modern management era. Methods and Results—Between October 2002 and October 2003, 354 consecutive adult patients with idiopathic, familial, or anorexigen-associated pulmonary arterial hypertension (56 incident and 298 prevalent cases) were prospectively enrolled. Patients were followed up for 3 years, and survival rates were analyzed. For incident cases, estimated survival (95% confidence intervals [CIs]) at 1, 2, and 3 years was 85.7% (95% CI, 76.5 to 94.9), 69.6% (95% CI, 57.6 to 81.6), and 54.9% (95% CI, 41.8 to 68.0), respectively. In a combined analysis population (incident patients and prevalent patients diagnosed within 3 years before study entry; n190), 1-, 2-, and 3-year survival estimates were 82.9% (95% CI, 72.4 to 95.0), 67.1% (95% CI, 57.1 to 78.8), and 58.2% (95% CI, 49.0 to 69.3), respectively. Individual survival analysis identified the following as significantly and positively associated with survival: female gender, New York Heart Association functional class I/II, greater 6-minute walk distance, lower right atrial pressure, and higher cardiac output. Multivariable analysis showed that being female, having a greater 6-minute walk distance, and exhibiting higher cardiac output were jointly significantly associated with improved survival. Conclusions—In the modern management era, idiopathic, familial, and anorexigen-associated pulmonary arterial hypertension remains a progressive, fatal disease. Mortality is most closely associated with male gender, right ventricular hemodynamic function, and exercise limitation. (Circulation. 2010;122:156-163.)

Abstract: Background— Inflammation is a feature of pulmonary arterial hypertension (PAH), and increased circulating levels of cytokines are reported in patients with PAH. However, to date, no information exists on the significance of elevated cytokines or their potential as biomarkers. We sought to determine the levels of a range of cytokines in PAH and to examine their impact on survival and relationship to hemodynamic indexes. Methods and Results— We measured levels of serum cytokines (tumor necrosis factor-α, interferon-γ and interleukin-1β, -2, -4, -5, -6, -8, -10, -12p70, and -13) using ELISAs in idiopathic and heritable PAH patients (n=60). Concurrent clinical data included hemodynamics, 6-minute walk distance, and survival time from sampling to death or transplantation. Healthy volunteers served as control subjects (n=21). PAH patients had significantly higher levels of interleukin-1β, -2, -4, -6, -8, -10, and -12p70 and tumor necrosis factor-α compared with healthy control subjects. Kaplan-Meier analysis sh...

Abstract: Rationale: Patients with chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) (overlap syndrome) are more likely to develop pulmonary hypertension than patients with either condition alone.Objectives: To assess the relation of overlap syndrome to mortality and first-time hospitalization because of COPD exacerbation and the effect of continuous positive airway pressure (CPAP) on these major outcomes.Methods: We included 228 patients with overlap syndrome treated with CPAP, 213 patients with overlap syndrome not treated with CPAP, and 210 patients with COPD without OSA. All were free of heart failure, myocardial infarction, or stroke. Median follow-up was 9.4 years (range, 3.3–12.7). End points were all-cause mortality and first-time COPD exacerbation leading to hospitalization.Measurements and Main Results: After adjustment for age, sex, body mass index, smoking status, alcohol consumption, comorbidities, severity of COPD, apnea-hypopnea index, and daytime sleepiness, patients wit...

Abstract: Pulmonary arterial hypertension (PAH) is a syndrome in which pulmonary arterial obstruction increases pulmonary vascular resistance, which leads to right ventricular (RV) failure and a 15% annual mortality rate. The present review highlights recent advances in the basic science of PAH. New concepts clarify the nature of PAH and provide molecular blueprints that explain how PAH is initiated and maintained. Five basic science concepts provide a framework to understand and treat PAH: (1) Endothelial dysfunction creates an imbalance that favors vasoconstriction, thrombosis, and mitogenesis. Restoration of this balance by inhibition of endothelin and thromboxane or augmentation of nitric oxide (NO) and prostacyclin is the paradigm on which most current therapy is based. (2) PAH has a genetic component. Mutations (bone morphogenetic protein receptor-2 [BMPR2]) and single-nucleotide polymorphisms (SNPs; ion channels and transporter genes) predispose to PAH. (3) Excess proliferation, impaired apoptosis, and glycolytic metabolism in pulmonary artery smooth muscle, fibroblasts, and endothelial cells suggest analogies to cancer. Many experimental therapies reduce PAH by decreasing the proliferation/apoptosis ratio; these include inhibitors of pyruvate dehydrogenase kinase (PDK), serotonin transporters (SERT), survivin, 3-hydroxy-3-methylglutaryl coenzyme A reductase, transcription factors (hypoxia-inducible factor [HIF]-1α and nuclear factor of activated T lymphocytes [NFAT]), and tyrosine kinases. Augmentation of voltage-gated K+ channels (Kv1.5) and BMPR2 signaling also addresses this imbalance. Tyrosine kinase inhibitors used to treat cancer are currently in phase 1 PAH trials. (4) Refractory vasoconstriction may occur due to rho kinase activation. Fewer than 20% of PAH patients respond to conventional vasodilators; however, refractory vasoconstriction may respond to rho kinase inhibitors. (5) The RV can be targeted therapeutically. Although increased afterload initiates RV failure, which is the major cause of death/dysfunction in PAH, the RV may be amenable to cardiac-targeted therapies. The RV in PAH has features of ischemic, hibernating myocardium. Guided by these new …

Abstract: This study aims to describe the haemodynamic and survival characteristics of patients with pulmonary hypertension in the recently individualised syndrome of combined pulmonary fibrosis and emphysema. A retrospective multicentre study was conducted in 40 patients (38 males; age 68±9 yrs; 39 smokers) with combined pulmonary fibrosis and emphysema, and pulmonary hypertension at right heart catheterisation. Dyspnoea was functional class II in 15%, III in 55% and IV in 30%. 6-min walk distance was 244±126 m. Forced vital capacity was 86±18%, forced expiratory volume in 1 s 78±19%, and carbon monoxide diffusion transfer coefficient 28±16% of predicted. Room air arterial oxygen tension was 7.5±1.6 kPa (56±12 mmHg). Mean pulmonary artery pressure was 40±9 mmHg, cardiac index 2.5±0.7 L·min -1·m -2 and pulmonary vascular resistance 521±205 dyn·s·cm -5. 1-yr survival was 60%. Higher pulmonary vascular resistance, higher heart rate, lower cardiac index and lower carbon monoxide diffusion transfer were associated with shorter survival. Patients with combined pulmonary fibrosis and emphysema syndrome and pulmonary hypertension confirmed by right heart catheterisation have a dismal prognosis despite moderately altered lung volumes and flows and moderately severe haemodynamic parameters. Copyright©ERS Journals Ltd 2010.

Abstract: Background— The plexiform lesion is the hallmark of severe pulmonary arterial hypertension. However, its genesis and hemodynamic effects are largely unknown because of the limited availability of lung tissue samples from patients with pulmonary arterial hypertension and the lack of appropriate animal models. This study investigated whether rats with severe progressive pulmonary hypertension developed plexiform lesions. Methods and Results— After a single subcutaneous injection of the vascular endothelial growth factor receptor blocker Sugen 5416, rats were exposed to hypoxia for 3 weeks. They were then returned to normoxia for an additional 10 to 11 weeks. Hemodynamic and histological examinations were performed at 13 to 14 weeks after the Sugen 5416 injection. All rats developed pulmonary hypertension (right ventricular systolic pressure ≈100 mm Hg) and severe pulmonary arteriopathy, including concentric neointimal and complex plexiform-like lesions. There were 2 patterns of complex lesion formation: a l...

Abstract: The diagnosis and assessment of pulmonary arterial hypertension (PAH) is a rapidly evolving area, with changes occurring in the definition of the disease, screening and diagnostic techniques, and staging and follow-up assessment. After 4th World Symposium on pulmonary hypertension (PH) which took place in Dana Point in early 2008, the definition of PH has been simplified (mean pulmonary artery pressure 25 mmHg) based on currently available evidences. The diagnosis of PH involves two stages: detection (determining the cause of a patient's symptoms, or to detect the presence of PAH in a high-risk patient) and characterization (determining the specific clinical context of the PH, including causal factors, associated diseases or substrates and hemodynamic perturbations). Echocardiography and right heart catheterization have been main diagnostic method in PAH. Also, there has been progress in imaging techniques and biomarkers used to screen patients for the disease and to follow up their response to therapy. Useful tools to predict outcome include functional class, exercise capacity, pulmonary hemodynamics, acute vasoreactivity, right ventricular function, as well as brain natriuretic peptide, endothelin-1, and so on. As new therapies have been developed for PAH, screening, prompt diagnosis, and accurate assessment of disease severity have become increasingly important. A clear definition of PH and the development of a rational approach to diagnostic assessment and follow-up using both conventional and new tools will be essential to advance proper treatment of patients.

Abstract: Background— Advanced therapy (AT) for pulmonary arterial hypertension in the context of congenital heart disease (Eisenmenger syndrome) improves pulmonary hemodynamics, functional class, and the 6-...

Abstract: Aims To assess the acute vasodilator response and long-term response to calcium-channel blockers (CCB) in pulmonary arterial hypertension (PAH) with associated conditions. Methods and results The response to acute vasodilator testing [>20% decrease in mean pulmonary artery pressure (mPAP) and total pulmonary resistance] was assessed in 663 consecutive PAH patients with connective tissue disease (CTD; n = 168), portal hypertension (PoPH; n = 153), anorexigen use ( n = 127), human immunodeficiency virus infection (HIV; n = 124), congenital heart disease (CHD; n = 50), and pulmonary veno-occlusive disease or capillary haemangiomatosis (PVOD/PCH; n = 41). An acute vasodilator response was observed in 13.4% of PAH-anorexigen patients, 12.2% of PVOD/PCH, 10.1% of CTD, 1.6% of HIV, 1.3% of PoPH, and was absent in CHD. A long-term response to CCB (marked haemodynamic improvement at 3–4 months and New York Heart Association functional class I or II after 1 year) was reported in 9.4% of PAH-anorexigen patients but was rare in HIV, PoPH, CTD (1.6, 0.7, and 0.6%, respectively) and absent in PVOD/PCH. All patients with a long-term CCB response were alive after 5 years; two deaths not related to PAH occurred after this time. Recent criteria for acute response based on the fall in mPAP to <40 mmHg are more specific to detect long-term responders to CCB. Conclusion A long-term CCB response was reported in patients with PAH associated with anorexigen use, but was rare in patients with PoPH or HIV and absent in PVOD/PCH, CHD, and the vast majority of CTD. The prognosis of long-term responders was favourable and related to the underlying cause of PAH.

Abstract: Pulmonary vascular dysfunction, pulmonary hypertension (PH), and resulting right ventricular (RV) failure occur in many critical illnesses and may be associated with a worse prognosis. PH and RV failure may be difficult to manage: principles include maintenance of appropriate RV preload, augmentation of RV function, and reduction of RV afterload by lowering pulmonary vascular resistance (PVR). We therefore provide a detailed update on the management of PH and RV failure in adult critical care. A systematic review was performed, based on a search of the literature from 1980 to 2010, by using prespecified search terms. Relevant studies were subjected to analysis based on the GRADE method. Clinical studies of intensive care management of pulmonary vascular dysfunction were identified, describing volume therapy, vasopressors, sympathetic inotropes, inodilators, levosimendan, pulmonary vasodilators, and mechanical devices. The following GRADE recommendations (evidence level) are made in patients with pulmonary vascular dysfunction: 1) A weak recommendation (very-low-quality evidence) is made that close monitoring of the RV is advised as volume loading may worsen RV performance; 2) A weak recommendation (low-quality evidence) is made that low-dose norepinephrine is an effective pressor in these patients; and that 3) low-dose vasopressin may be useful to manage patients with resistant vasodilatory shock. 4) A weak recommendation (low-moderate quality evidence) is made that low-dose dobutamine improves RV function in pulmonary vascular dysfunction. 5) A strong recommendation (moderate-quality evidence) is made that phosphodiesterase type III inhibitors reduce PVR and improve RV function, although hypotension is frequent. 6) A weak recommendation (low-quality evidence) is made that levosimendan may be useful for short-term improvements in RV performance. 7) A strong recommendation (moderate-quality evidence) is made that pulmonary vasodilators reduce PVR and improve RV function, notably in pulmonary vascular dysfunction after cardiac surgery, and that the side-effect profile is reduced by using inhaled rather than systemic agents. 8) A weak recommendation (very-low-quality evidence) is made that mechanical therapies may be useful rescue therapies in some settings of pulmonary vascular dysfunction awaiting definitive therapy. This systematic review highlights that although some recommendations can be made to guide the critical care management of pulmonary vascular and right ventricular dysfunction, within the limitations of this review and the GRADE methodology, the quality of the evidence base is generally low, and further high-quality research is needed.

Abstract: Objective. To measure the prevalence of different types of pulmonary hypertension (PH) and to identify patients with systemic sclerosis (SSc) at highest risk in a multicenter European sample, with a metaanalysis of relevant studies. Methods. Consecutive patients with SSc recruited at 11 French and Italian centers underwent detailed evaluations, including Doppler echocardiography, chest computed tomography, pulmonary function tests, and right-heart catheterization (RHC), to detect the presence and causes of PH. A metaanalysis was performed, including data from 4 other studies. Results. Among 206 patients in whom it was suspected, PH was confirmed by RHC in 83 patients (7%). Precapillary PH was found in 64 patients (5%), of whom 42 had pulmonary arterial hypertension (PAH) and 22 had PH secondary to interstitial lung disease (ILD). RHC identified 17 patients (1%) with postcapillary PH secondary to left-heart disease. Patients with DLCO/alveolar volume < 70% were more likely to have precapillary PH (87.5% vs 42%; p < 0.0001). Precapillary and postcapillary PH were associated with advanced age (68 ± 14 vs 59 ± 12 yrs, p < 0.0001, and 74 ± 16 vs 61.5 ± 10 yrs, p < 0.0001, respectively). The metaanalysis of 3818 patients showed a prevalence of precapillary PH of 9% (95% CI 6%–12%) and identified advanced age, longer disease duration, and limited cutaneous disease subset as risk factors for this condition. Conclusion. The prevalence of precapillary PH in our multicenter study of SSc was 5%, and in the metaanalysis 9%. Our observations support use of RHC to confirm the presence of precapillary PH suspected by noninvasive testing. We also identified patients at high risk who should be carefully monitored.

Abstract: Rationale: Most patients with pulmonary arterial hypertension (PAH) die from right heart failure. β-Adrenergic receptor blockade reduces mortality by about 30% in patients with left-sided systolic heart failure, but is not used in PAH.Objectives: To assess the effect of the adrenergic receptor blocker carvedilol on the pulmonary circulation and right heart in experimental pulmonary hypertension in rats.Methods: Angioproliferative pulmonary hypertension was induced in rats by combined exposure to the vascular endothelial growth factor–receptor antagonist SU5416 and hypoxia. Carvedilol treatment was started after establishment of pulmonary hypertension and right heart dysfunction.Measurements and Main Results: Compared with vehicle-treated animals, treatment with carvedilol resulted in increased exercise endurance; improved right ventricular (RV) function (increased tricuspid annular plane systolic excursion and decreased RV dilatation); and an increased cardiac output. The morphology of the pulmonary vesse...

Abstract: Severe pulmonary hypertension is irreversible and often fatal. Abnormal proliferation and resistance to apoptosis of endothelial cells (ECs) and hypertrophy of smooth muscle cells in this disease are linked to decreased mitochondria and preferential energy generation by glycolysis. We hypothesized this metabolic shift of pulmonary hypertensive ECs is due to greater hypoxia inducible-factor1α (HIF-1α) expression caused by low levels of nitric oxide combined with low superoxide dismutase activity. We show that cultured ECs from patients with idiopathic pulmonary arterial hypertension (IPAH-ECs) have greater HIF-1α expression and transcriptional activity than controls under normoxia or hypoxia, and pulmonary arteries from affected patients have increased expression of HIF-1α and its target carbonic anhydrase IX. Decreased expression of manganese superoxide dismutase (MnSOD) in IPAH-ECs paralleled increased HIF-1α levels and small interfering (SI) RNA knockdown of MnSOD, but not of the copper-zinc SOD, increased HIF-1 protein expression and hypoxia response element (HRE)-driven luciferase activity in normoxic ECs. MnSOD siRNA also reduced nitric oxide production in supernatants of IPAH-ECs. Conversely, low levels of a nitric oxide donor reduced HIF-1α expression in normoxic IPAH-ECs. Finally, mitochondria numbers increased in IPAH-ECs with knockdown of HIF-1α. These findings indicate that alterations of nitric oxide and MnSOD contribute to pathological HIF-1α expression and account for lower numbers of mitochondria in IPAH-ECs.

Abstract: Rationale: An activated vasoconstrictive, proliferative, and fibrotic axis of the renin angiotensin system (angiotensin-converting enzyme [ACE]/angiotensin [Ang]II/AngII type 1 receptor) has been implicated in the pathophysiology of pulmonary fibrosis (PF) and pulmonary hypertension (PH). The recent discovery of a counterregulatory axis of the renin angiotensin system composed of ACE2/Ang-(1–7)/Mas has led us to examine the role of this vasoprotective axis on such disorders.Objectives: We hypothesized that Ang-(1–7) treatment would exert protective effects against PF and PH.Methods: Lentiviral packaged Ang-(1–7) fusion gene or ACE2 cDNA was intratracheally administered into the lungs of male Sprague Dawley rats. Two weeks after gene transfer, animals received bleomycin (2.5 mg/kg). In a subsequent study, animals were administered monocrotaline (MCT, 50 mg/kg).Measurements and Main Results: In the PF study, bleomycin administration resulted in a significant increase in right ventricular systolic pressure, ...

Abstract: BACKGROUND: Chronic thromboembolic pulmonary hypertension after pulmonary embolism is associated with high morbidity and mortality. Understanding the incidence of chronic thromboembolic pulmonary hypertension after pulmonary embolism is important for evaluating the need for screening but is also a subject of debate because of different inclusion criteria among previous studies. We determined the incidence of chronic thromboembolic pulmonary hypertension after acute pulmonary embolism and the utility of a screening program for this disease. DESIGN AND METHODS: We conducted a cohort screening study in an unselected series of consecutive patients (n=866) diagnosed with acute pulmonary embolism between January 2001 and July 2007. All patients who had not been previously diagnosed with pulmonary hypertension (PH) and had survived until study inclusion were invited for echocardiography. Patients with echocardiographic suspicion of PH underwent complete work-up for chronic thromboembolic pulmonary hypertension, including ventilation-perfusion scintigraphy and right heart catheterization. RESULTS: After an average follow-up of 34 months of all 866 patients, PH was diagnosed in 19 patients by routine clinical care and in 10 by our screening program; 4 patients had chronic thromboembolic pulmonary hypertension, all diagnosed by routine clinical care. The cumulative incidence of chronic thromboembolic pulmonary hypertension after all cause pulmonary embolism was 0.57% (95% confidence interval [CI] 0.02-1.2%) and after unprovoked pulmonary embolism 1.5% (95% CI 0.08-3.1%). CONCLUSIONS: Because of the low incidence of chronic thromboembolic pulmonary hypertension after pulmonary embolism and the very low yield of the echocardiography based screening program, wide scale implementation of prolonged follow-up including echocardiography of all patients with pulmonary embolism to detect chronic thromboembolic pulmonary hypertension does not seem to be warranted.

Abstract: Acute right ventricular failure in the setting of pulmonary arterial hypertension (PAH) often requires hospitalisation in intensive care units (ICU) to manage the subsequent low cardiac output and its consequences. There are very few data on these acute events. We recorded demographic, clinical and biological data and therapy in consecutive patients suffering from acute right heart failure requiring catecholamine treatment in the ICU of the French referral centre for pulmonary hypertension. These variables were analysed according to the survival status in ICU. 46 patients were included, the mean age was 50.3 yrs. ICU mortality was 41%. We found no difference in terms of demographics, clinical data, last haemodynamic measurements at admission. Systemic arterial pressure was significantly lower in the subgroup of patients whose clinical course was fatal. Plasma brain natriuretic peptide (BNP), C-reactive protein (CRP), serum sodium and creatinine at admission correlated with survival. Demonstration of an infection during the ICU stay was associated with a worse prognosis. These preliminary results underline the importance of some simple clinical and biological parameters in the prognostic evaluation of acute heart failure in the setting of PAH. Whether these parameters can guide therapy needs to be further investigated.

Abstract: Background— Current guidelines recommend mitral valve surgery for asymptomatic patients with severe degenerative mitral regurgitation and preserved left ventricular systolic function when exercise pulmonary hypertension (PHT) is present. However, the determinants of exercise PHT have not been evaluated. The aim of this study was to identify the echocardiographic predictors of exercise PHT and the impact on symptoms. Methods and Results— Comprehensive resting and exercise transthoracic echocardiography was performed in 78 consecutive patients (age, 61±13 years; 56% men) with at least moderate degenerative mitral regurgitation (effective regurgitant orifice area =43±20 mm2; regurgitant volume =71±27 mL). Exercise PHT was defined as a systolic pulmonary arterial pressure (SPAP) >60 mm Hg. Exercise PHT was present in 46% patients. In multivariable analysis, exercise effective regurgitant orifice was an independent determinant of exercise SPAP (P<0.0001) and exercise PHT (P=0.002). Resting PHT and exercise PHT...

Abstract: Background— We tested the hypothesis that right ventricular (RV) pressure overload affects RV function and further influences left ventricular (LV) geometry, which adversely affects LV twist mechanics and segmental function. Methods and Results— Echocardiographic images were prospectively acquired in 44 patients (age, 46±12 years; 82% women) with evidence of pulmonary hypertension (estimated pulmonary artery systolic pressure, 71±23 mm Hg) and in 44 age- and gender-matched healthy subjects. Patients with intrinsic LV diseases were excluded. RV lateral wall longitudinal strain (LS) and interventricular septal (IVS) LS were reduced in the pulmonary hypertension group compared with control subjects (−15.9±7.6% versus −25.5±6.1%, P<0.001; and −17.3±4.4% versus −20.2±3.9%, P=0.002, respectively), whereas LV lateral wall LS was preserved. RV lateral wall LS and IVS LS, but not LV lateral wall LS, correlated with pulmonary artery systolic pressure (r=0.56, P<0.01; r=0.32, P<0.01) and LV eccentricity index (r=0.5...

Abstract: Pulmonary arterial hypertension is caused by excessive growth of vascular cells that eventually obliterate the pulmonary arterial lumen, causing right ventricular failure and premature death. Despite some available treatments, its prognosis remains poor, and the cause of the vascular remodeling remains unknown. The vascular smooth muscle cells that proliferate during pulmonary arterial hypertension are characterized by mitochondrial hyperpolarization, activation of the transcription factor NFAT (nuclear factor of activated T cells), and down-regulation of the voltage-gated potassium channel Kv1.5, all of which suppress apoptosis. We found that mice lacking the gene for the metabolic enzyme malonyl–coenzyme A (CoA) decarboxylase (MCD) do not show pulmonary vasoconstriction during exposure to acute hypoxia and do not develop pulmonary arterial hypertension during chronic hypoxia but have an otherwise normal phenotype. The lack of MCD results in an inhibition of fatty acid oxidation, which in turn promotes glucose oxidation and prevents the shift in metabolism toward glycolysis in the vascular media, which drives the development of pulmonary arterial hypertension in wild-type mice. Clinically used metabolic modulators that mimic the lack of MCD and its metabolic effects normalize the mitochondrial-NFAT-Kv1.5 defects and the resistance to apoptosis in the proliferated smooth muscle cells, reversing the pulmonary hypertension induced by hypoxia or monocrotaline in mice and rats, respectively. This study of fatty acid oxidation and MCD identifies a critical role for metabolism in both the normal pulmonary circulation (hypoxic pulmonary vasoconstriction) and pulmonary hypertension, pointing to several potential therapeutic targets for the treatment of this deadly disease.

Abstract: Objective To clarify the clinical characteristics and epidemiology of idiopathic pulmonary arterial hypertension (IPAH) in childhood, a rare condition with a bad prognosis, poorly documented in children. Also, to describe the long-term outcome. Design A retrospective study of 7 years9 experience. Setting UK Service for Pulmonary Hypertension in Children based at a tertiary referral centre. Patients 64 children. Interventions Patients were initially treated with prostanoids (n=15), bosentan (n=23), sildenafil (n=9), combination therapy (n=11) or calcium channel antagonists (n=6). Main outcome measures WHO functional class, distance walked in 6 minutes, escalation of therapy, survival, transplant-free survival. Results Incidence of IPAH was 0.48 cases per million children per year and the prevalence was 2.1 cases per million. 31% presented with syncope. Oedema was rare. During the first year of follow-up WHO functional class and 6-minute walk distance improved significantly. Survival at 1, 3 and 5 years was 89%, 84% and 75%, respectively; while transplant-free survival was 89% 76% and 57%, respectively. Factors predicting worse survival were WHO functional class (HR 2.4, p=0.04) and poor height and weight z-score (p Conclusions We showed, for the first time, that the incidence of IPAH is lower in children than adults and that the clinical features can be different. Most children present with clinical evidence of advanced disease and clinical status at presentation is predictive of outcome. This 7-year experience confirms the significant improvement in survival over historical controls.

Abstract: Aims To evaluate the efficacy of combining the dual endothelin receptor antagonist, bosentan, and the phosfodiesterase-5-inhibitor, sildenafil, in patients with Eisenmenger syndrome. Methods and results The study was a randomized, placebo-controlled, double-blinded, cross-over design. Patients with Eisenmenger syndrome ( n = 21) were treated open label with bosentan for 9 months. After 3 months, sildenafil/placebo was added for 3 months, and a cross-over was performed for the last 3 months. At baseline and after 3, 6, and 9 months, patients were examined with 6 min walk test, oxygen saturations, N-terminal pro-brain natriuretic peptide, New York Heart Association (NYHA) classification, cardiac catheterization, and magnetic resonance imaging. The primary endpoint was changed in 6 min walk distance (MWD). Bosentan improved the 6 MWD (377 vs. 414 m, P = 0.001), pulmonary vascular resistance (PVR) (28 vs. 22 wood, P = 0.01), and pulmonary blood flow (2.6 vs. 3.5 L/min, P = 0.01). Adding sildenafil to bosentan did not improve the 6 MWD significantly (21 vs. 8 m, P = 0.48), but increased saturation at rest (2.9 vs. –1.8%, P < 0.01). Conclusion In Eisenmenger syndrome, treatment with bosentan significantly improved walking distance, pulmonary blood flow, and PVR. Adding sildenafil to bosentan did not significantly improve walking distance but did increase saturation at rest. : NCT00303004.

Abstract: Rationale: The sympathetic nervous system has been reported to be activated in pulmonary arterial hypertension (PAH).Objectives: We investigated the prognostic significance of muscle sympathetic nervous system activity (MSNA) in PAH.Methods: Thirty-two patients with PAH were included in the study and underwent a measurement of MSNA over a 6-year period of time. They had undergone a concomitant evaluation of New York Heart Association (NYHA) functional class, a 6-minute walk distance (6MWD), an echocardiographic examination, and a right heart catheterization for diagnostic or reevaluation purposes. The median follow-up time was 20.6 months (interquartile range, 45.8 mo). Clinical deterioration was defined by listing for transplantation or death.Measurements and Main Results: Seventeen patients presented with clinical deterioration. As compared with the 15 others, they had an increased MSNA (80 ± 12 vs. 52 ± 18 bursts/min; P < 0.001) and heart rate (88 ± 17 vs. 74 ± 12 bpm; P = 0.01), a lower 6MWD (324 ± 11...

Abstract: A combination of CT and echocardiographic markers of pulmonary hypertension in the form of a composite index is more strongly related to mean pulmonary arterial pressure than either test in isolation.

Abstract: Background— Pulmonary arterial hypertension is a progressive proliferative vasculopathy of the small pulmonary arteries that is characterized by a primary failure of the endothelial nitric oxide and prostacyclin vasodilator pathways, coupled with dysregulated cellular proliferation. We have recently discovered that the endogenous anion salt nitrite is converted to nitric oxide in the setting of physiological and pathological hypoxia. Considering the fact that nitric oxide exhibits vasoprotective properties, we examined the effects of nitrite on experimental pulmonary arterial hypertension. Methods and Results— We exposed mice and rats with hypoxia or monocrotaline-induced pulmonary arterial hypertension to low doses of nebulized nitrite (1.5 mg/min) 1 or 3 times a week. This dose minimally increased plasma and lung nitrite levels yet completely prevented or reversed pulmonary arterial hypertension and pathological right ventricular hypertrophy and failure. In vitro and in vivo studies revealed that nitrit...

Abstract: Chronic hypoxia contributes to pulmonary hypertension through complex mechanisms that include enhanced NADPH oxidase expression and reactive oxygen species (ROS) generation in the lung. Stimulation of peroxisome proliferator–activated receptor γ (PPARγ) reduces the expression and activity of NADPH oxidase. Therefore, we hypothesized that activating PPARγ with rosiglitazone would attenuate chronic hypoxia–induced pulmonary hypertension, in part, through suppressing NADPH oxidase–derived ROS that stimulate proliferative signaling pathways. Male C57Bl/6 mice were exposed to chronic hypoxia (CH, FiO2 10%) or room air for 3 or 5 weeks. During the last 10 days of exposure, each animal was treated daily by gavage with either the PPARγ ligand, rosiglitazone (10 mg/kg/d) or with an equal volume of vehicle. CH increased: (1) right ventricular systolic pressure (RVSP), (2) right ventricle weight, (3) thickness of the walls of small pulmonary vessels, (4) superoxide production and Nox4 expression in the lung, and (5)...

Abstract: Background— Current guidelines recommend mitral valve surgery for asymptomatic patients with severe degenerative mitral regurgitation and preserved left ventricular systolic function when exercise pulmonary hypertension (PHT) is present. However, the determinants of exercise PHT have not been evaluated. The aim of this study was to identify the echocardiographic predictors of exercise PHT and the impact on symptoms. Methods and Results— Comprehensive resting and exercise transthoracic echocardiography was performed in 78 consecutive patients (age, 61±13 years; 56% men) with at least moderate degenerative mitral regurgitation (effective regurgitant orifice area =43±20 mm2; regurgitant volume =71±27 mL). Exercise PHT was defined as a systolic pulmonary arterial pressure (SPAP) >60 mm Hg. Exercise PHT was present in 46% patients. In multivariable analysis, exercise effective regurgitant orifice was an independent determinant of exercise SPAP (P<0.0001) and exercise PHT (P=0.002). Resting PHT and exercise PHT were associated with markedly reduced 2-year symptom-free survival (36±14% versus 59±7%, P=0.04; 35±8% versus 75±7%, P<0.0001). After adjustment, although the impact of resting PHT was no longer significant, exercise PHT was identified as an independent predictor of the occurrence of symptoms (hazard ratio=3.4; P=0.002). Receiver-operating characteristics curves revealed that exercise PHT (SPAP >56 mm Hg) was more accurate than resting PHT (SPAP >36 mm Hg) in predicting the occurrence of symptoms during follow-up (P=0.032). Conclusions— Exercise PHT is frequent in patients with asymptomatic degenerative mitral regurgitation. Exercise mitral regurgitation severity is a strong independent predictor of both exercise SPAP and exercise PHT. Exercise PHT is associated with markedly low 2-year symptom-free survival, emphasizing the use of exercise echocardiography. An exercise SPAP >56 mm Hg accurately predicts the occurrence of symptoms.