Objectives Our goal was to investigate the effect of treatment with the oral dual endothelin receptor antagonist bosentan on the hemodynamics and exercise capacity of patients with chronic thromboembolic pulmonary hypertension (CTEPH). Background CTEPH is characterized by vascular obstruction and remodeling, leading to increased pulmonary vascular resistance (PVR). Although pulmonary endarterectomy (PEA) is potentially curative, medical therapy is needed in patients with inoperable disease or persistent/recurrent pulmonary hypertension after PEA. Methods The BENEFiT (Bosentan Effects in iNopErable Forms of chronIc Thromboembolic pulmonary hypertension) study was a double-blind, randomized, placebo-controlled study in CTEPH including patients with either inoperable CTEPH or persistent/recurrent pulmonary hypertension after PEA (>6 months after PEA). Independent coprimary end points were change in PVR as a percentage of baseline and change from baseline in 6-min walk distance after 16 weeks of treatment with bosentan or placebo. Secondary end points included change from baseline in World Health Organization functional class and other hemodynamic parameters. Results One hundred fifty-seven patients were enrolled and randomized: 80 to placebo, 77 to bosentan. A statistically significant treatment effect (TE) of bosentan over placebo on PVR was demonstrated: −24.1% of baseline (95% confidence interval [CI]: −31.5% to −16.0%; p < 0.0001). Total pulmonary resistance (TE: −193 dyn·s·cm−5 ; 95% CI: −283 to −104 dyn·s·cm−5 ; p < 0.0001) and cardiac index (TE: 0.3 l·min−1 ·m−2 ; 95% CI: 0.14 to 0.46 l·min−1 ·m−2 ; p = 0.0007) improved. Mean TE on 6-min walk distance was +2.2 m (95% CI: −22.5 to 26.8 m; p = 0.5449). Bosentan treatment was well tolerated. Conclusions This study demonstrated a positive TE of bosentan on hemodynamics in this patient population. No improvement was observed in exercise capacity. Further trials are needed to define the role of medical therapy in patients with CTEPH (Bosentan Effects in Inoperable Forms of Chronic Thromboembolic Pulmonary Hypertension; NCT00313222 ).
Extracellular vesicles (EVs) from mice with monocrotaline (MCT)-induced pulmonary hypertension (PH) induce PH in healthy mice, and the exosomes (EXO) fraction of EVs from mesenchymal stem cells (MSCs) can blunt the development of hypoxic PH. We sought to determine whether the EXO fraction of EVs is responsible for modulating pulmonary vascular responses and whether differences in EXO-miR content explains the differential effects of EXOs from MSCs and mice with MCT-PH. Plasma, lung EVs from MCT-PH, and control mice were divided into EXO (exosome), microvesicle (MV) fractions and injected into healthy mice. EVs from MSCs were divided into EXO, MV fractions and injected into MCT-treated mice. PH was assessed by right ventricle-to-left ventricle + septum (RV/LV + S) ratio and pulmonary arterial wall thickness-to-diameter (WT/D) ratio. miR microarray analyses were also performed on all EXO populations. EXOs but not MVs from MCT-injured mice increased RV/LV + S, WT/D ratios in healthy mice. MSC-EXOs prevented any increase in RV/LV + S, WT/D ratios when given at the time of MCT injection and reversed the increase in these ratios when given after MCT administration. EXOs from MCT-injured mice and patients with idiopathic pulmonary arterial hypertension (IPAH) contained increased levels of miRs-19b,-20a,-20b, and -145, whereas miRs isolated from MSC-EXOs had increased levels of anti-inflammatory, anti-proliferative miRs including miRs-34a,-122,-124, and -127. These findings suggest that circulating or MSC-EXOs may modulate pulmonary hypertensive effects based on their miR cargo. The ability of MSC-EXOs to reverse MCT-PH offers a promising potential target for new PAH therapies.
Background Pulmonary hypertension (PH) is hemodynamically classified as pre-capillary (as seen in idiopathic pulmonary arterial hypertension [IPAH]) or post-capillary (as seen in heart failure with preserved ejection fraction [HFpEF]). Overlaps between these conditions exist. Some patients present with risk factors for left heart disease but pre-capillary PH, whereas patients with HFpEF may have combined pre- and post-capillary PH. Objectives This study sought to further characterize similarities and differences among patient populations with either PH-HFpEF or IPAH. Methods We used registry data to analyze clinical characteristics, hemodynamics, and treatment responses in patients with typical IPAH (<3 risk factors for left heart disease; n = 421), atypical IPAH (≥3 risk factors for left heart disease; n = 139), and PH-HFpEF (n = 226) receiving PH-targeted therapy. Results Compared with typical IPAH, patients with atypical IPAH and PH-HFpEF were older, had a higher body mass index, had more comorbidities, and had a lower 6-min walking distance, whereas mean pulmonary artery pressure (46.9 ± 13.3 mm Hg vs. 43.9 ± 10.7 mm Hg vs. 45.7 ± 9.4 mm Hg, respectively) and cardiac index (2.3 ± 0.8 l/min/m vs. 2.2 ± 0.8 l/min/m vs. 2.2 ± 0.7 l/min/m , respectively) were comparable among groups. After initiation of targeted PH therapies, all groups showed improvement in exercise capacity, functional class, and natriuretic peptides from baseline to 12 months, but treatment effects were less pronounced in patients with PH-HFpEF than typical IPAH; with atypical IPAH in between. Survival rates at 1, 3, and 5 years were almost identical for the 3 groups. Conclusions Patients with atypical IPAH share features of both typical IPAH and PH-HFpEF, suggesting that there may be a continuum between these conditions.
Anomalous origin of the pulmonary artery from the ascending aorta can lead to congestive heart failure in infancy, and with advancing age many patients will experience severe pulmonary hypertension. Surgical intervention has high mortality and morbidity risks if this happens. Strategies to manage these patients seem only limited to heart–lung transplantation or lung transplantation. Here, we successfully performed surgical intervention in an adult patient who had anomalous origin of the right pulmonary artery from the ascending aorta with high pressures in the ascending aorta and normally originating pulmonary artery.
Background Pulmonary hypertension (PHT) lacks community prevalence and outcome data. Objective To characterise minimum ‘indicative’ prevalences and mortality data for all forms of PHT in a selected population with an elevated estimated pulmonary artery systolic pressure (ePASP) on echocardiography. Design Observational cohort study. Setting Residents of Armadale and the surrounding region in Western Australia (population 165 450) referred to our unit for transthoracic echocardiography between January 2003 and December 2009. Results Overall, 10 314 individuals (6.2% of the surrounding population) had 15 633 echo studies performed. Of these, 3320 patients (32%) had insufficient TR to ePASP and 936 individuals (9.1%, 95% CI 8.6% to 9.7%) had PHT, defined as, ePASP>40 mm Hg. The minimum ‘indicative’ prevalence for all forms of PHT is 326 cases/100 000 inhabitants of the local population, with left heart disease-associated PHT being the commonest cause (250 cases/100 000). 15 cases of pulmonary arterial hypertension/100 000 inhabitants were identified and an additional 144 individuals (15%) with no identified cause for their PHT. The mean time to death for those with ePASP >40 mm Hg, calculated from the first recorded ePASP, was 4.1 years (95% CI 3.9 to 4.3). PHT increased mortality whatever the underlying cause, but patients with PHT from left heart disease had the worst prognosis and those with idiopathic pulmonary arterial hypertension receiving disease-specific treatment the best prognosis. Risk of death increased with PHT severity: severe pulmonary hypertension shortened the lifespan by an average of 1.1 years compared with mild pulmonary hypertension. Conclusions In this cohort, PHT was common and deadly. Left heart disease was the most common cause and had the worst prognosis and treated pulmonary arterial hypertension had the best prognosis.
Background Pulmonary hypertension (PH) is a severe progressive disease. Though five subgroups are recognised, reports on survival focus mainly on pulmonary arterial hypertension (PAH). Methods Long-term transplant-free survival, and its determinants, were investigated in patients with PH (diagnosed by right heart catheterization) within a prospective registry at a single referral center in Giessen, Germany. Results In total, 2067 patients were enrolled (PAH, 685 patients [33.1%]; pulmonary venous hypertension, 307 patients [14.9%]; PH due to lung diseases (LD-PH), 546 patients [26.4%; mainly interstitial lung disease and chronic obstructive pulmonary disease]; chronic thromboembolic PH, 459 patients [22.2%]; PH owing to miscellaneous/unknown causes, 70 patients [3.4%]). Median follow-up was 37 months. Differences in transplant-free survival between etiological groups were highly significant ( p < 0.001), with 1-, 3-, and 5-year survival rates of 88.2%, 72.2%, and 59.4%, respectively, for those with PAH compared with 79.5%, 52.7%, and 38.1%, respectively, for patients with LD-PH. Patients’ age, sex, and 6-minute walk distance (6MWD), but not New York Heart Association (NYHA) functional class, associated significantly with survival across all PH subtypes in multivariate Cox regression analyses. Conclusions This is the largest reported single-center PH cohort. Some parameters used in clinical practice do not independently predict survival. Age, sex, and 6MWD outperformed NYHA functional class in predicting survival across all etiologic groups.
Objective Pulmonary endarterectomy is the treatment of choice for chronic thromboembolic pulmonary hypertension. In many patients hemodynamics are normalized early after surgical intervention. However, the effect of residual pulmonary hypertension on postoperative clinical status and survival is unknown. Methods Data were collected prospectively on all patients who underwent pulmonary endarterectomy in a continuous national series between 1997 and December 2007. Postoperatively, patients underwent scheduled reinvestigation, including functional testing and right heart catheterization, at 3 months after the operation. They were divided into 2 groups based on mean pulmonary artery pressure: group 1, less than 30 mm Hg; group 2, 30 mm Hg or greater. Results Three hundred fourteen patients underwent pulmonary endarterectomy, survived to hospital discharge, and completed the 3-month follow-up period. At 3 months after pulmonary endarterectomy, there was a significant reduction in mean pulmonary artery pressure for the whole cohort (48 ± 12 to 26 ± 10 mm Hg, P < .001). However, 31% of the patients had residual pulmonary hypertension. Group 1 patients enjoyed significantly better exercise capacity and improved symptoms compared with group 2 patients. In addition, there were significantly fewer patients receiving targeted medical therapy in group 1 versus group 2 (0% vs 25%, P < .001). Conditional survival after discharge from the hospital for the whole cohort was 90.0% at 5 years and was not different between groups (90.3% for group 1 vs 89.9% for group 2, P = .36). Conclusions For patients undergoing pulmonary endarterectomy, survival after hospital discharge is excellent. Residual pulmonary hypertension significantly compromised symptom status and functional capacity but did not appear to adversely affect medium-term survival. The effect of targeted medical therapy in patients with residual pulmonary hypertension after pulmonary endarterectomy needs to be evaluated further.
Aims Pulmonary arterial hypertension (PAH) occurs more frequently in women with mutations in bone morphogenetic protein receptor type 2 (BMPR2) and dysfunctional BMPR2 signalling underpinning heritable PAH. We have previously shown that serotonin can uncover a pulmonary hypertensive phenotype in BMPR2(+/-) 2 mice and that oestrogen can increase serotinergic signalling in human pulmonary arterial smooth muscle cells (hPASMCs). Hence, here we wished to characterize the expression of oestrogen receptors (ERs) in male and female human pulmonary arteries and have examined the influence of oestrogen and serotonin on BMPR2 and ER alpha expression. Methods and results By immunohistochemistry, we showed that ER alpha, ER beta, and G-protein-coupled receptors are expressed in human pulmonary arteries localizing mainly to the smooth muscle layer which also expresses the serotonin transporter (SERT). Protein expression of ER alpha protein was higher in female PAH patient hPASMCs compared with male and serotonin also increased the expression of ER alpha. 17 beta-estradiol induced proliferation of hPASMCs via ER alpha activation and this engaged mitogen-activated protein kinase and Akt signalling. Female mice over-expressing SERT (SERT+ mice) develop PH and the ER alpha antagonist MPP attenuated the development of PH in normoxic and hypoxic female SERT+ mice. The therapeutic effects of MPP were accompanied by increased expression of BMPR2 in mouse lung. Conclusion ER alpha is highly expressed in female hPASMCs from PAH patients and mediates oestrogen-induced proliferation of hPASMCs via mitogen-activated protein kinase and Akt signalling. Serotonin can increase ER alpha expression in hPASMCs and antagonism of ER alpha reverses serotonin-dependent PH in the mouse and increases BMPR2 expression.