Clinical and translational research has played a major role in advancing our understanding of pulmonary hypertension (PH), including pulmonary arterial hypertension and other forms of PH with severe vascular remodelling (e.g. chronic thromboembolic PH and pulmonary veno-occlusive disease). However, PH remains an incurable condition with a high mortality rate, underscoring the need for a better transfer of novel scientific knowledge into healthcare interventions. Herein, we review recent findings in pathology (with the questioning of the strict morphological categorisation of various forms of PH into pre- or post-capillary involvement of pulmonary vessels) and cellular mechanisms contributing to the onset and progression of pulmonary vascular remodelling associated with various forms of PH. We also discuss ways to improve management and to support and optimise drug development in this research field.

OBJECTIVE:Choices of pharmacologic therapies for pulmonary arterial hypertension (PAH) are ideally guided by high-level evidence. Th e objective of this guideline is to provide clinicians advice regarding pharmacologic therapy for adult patients with PAH as informed by available evidence. METHODS:Th is guideline was based on systematic reviews of English language evidence published between 1990 and November 2013, identified using the MEDLINE and Cochrane Library databases. Th e strength of available evidence was graded using the Grades of Recommendations, Assessment, Development, and Evaluation methodology. Guideline recommendations, or consensus statements when available evidence was insufficient to support recommendations, were developed using a modifi ed Delphi technique to achieve consensus. RESULTS:Available evidence is limited in its ability to support high-level recommendations. Th erefore, we draft ed consensus statements to address many clinical questions regarding pharmacotherapy for patients with PAH. A total of 79 recommendations or consensus statements were adopted and graded.CONCLUSIONS: Clinical decisions regarding pharmacotherapy for PAH should be guided by high-level recommendations when suffi cient evidence is available. Absent higher level evidence, consensus statements based upon available information must be used. Further studies are needed to address the gaps in available knowledge regarding optimal pharmacotherapy for PAH. ABBREVIATIONS : 6MWD 5 6-min walk distance ; AHRQ 5 Agency for Healthcare Research and Quality ; ARIES 5 Ambrisentan in Pulmonary Arterial Hypertension, Randomized Double-Blind, PlaceboControlled, Multicenter, Efficacy Study ; BNP 5 brain natriuretic peptide ; CB 5 consensus-based ; CCB 5 calcium channel blocker ; CO 5 cardiac output ; COI 5 conflict of interest ; CTEPH 5 chronic thromboembolic pulmonary hypertension ; EPC 5 Evidence-Based Practice Center ; ETRA 5 endothelin receptor antagonist ; FC 5 functional class ; FDA 5 US Food and Drug Administration ; GOC 5 Guidelines Oversight Committee ; GRADE 5 Grades of Recommendations, Assessment , Development , and Evaluation ; HR 5 hazard ratio ; IOM 5 Institute of Medicine ; IPAH 5 idiopathic pulmonary arterial hypertension ; mPAP 5 mean pulmonary artery pressure ; PAH 5 pulmonary arterial hypertension ; PDE5 5 phosphodiesterase-5 ; PH 5 pulmonary hypertension ; PVR 5 pulmonary vascular resistance ; RCT 5 randomized controlled trial ; WHO 5 World Health Organization For treatment naive PAH patients with WHOFC I symptoms, we suggest continued monitoring for the development of symptoms that would signal disease progression and warrant the initiation of pharmacotherapy (Grade CB) . 5. We suggest that patients at risk for the development of PAH (eg, patients with systemic sclerosis or the presence of a known mutation placing the patient at risk for PAH) be monitored for the development of symptoms of PAH (Grade CB) . 6. We suggest also that contributing causes of PH (eg, sleep apnea and systemic hypertension) in patients wi...

of submassive pulmonary embolism with tenecteplase or placebo: cardiopulmonary outcomes at 3 months: multicenter double-blind, placebocontrolled randomized trial. J Thromb Haemost 2014; 12: 459-68.Summary. Background: Acute pulmonary embolism (PE) can worsen quality of life due to persistent dyspnea or exercise intolerance. Objective: Test if tenecteplase increases the probability of a favorable composite patient-oriented outcome after submassive PE. Methods: Normotensive patients with PE and right ventricular (RV) strain (by echocardiography or biomarkers) were enrolled from eight hospitals. All patients received lowmolecular-weight heparin followed by random assignment to either a single weight-based bolus of tenecteplase or placebo, administered in a double-blinded fashion. The primary composite outcome included: (i) death, circulatory shock, intubation or major bleeding within 5 days or (ii) recurrent PE, poor functional capacity (RV dysfunction with either dyspnea at rest or exercise intolerance) or an SF36â Physical Component Summary (PCS) score < 30 at 90-day follow-up. Results: Eighty-three patients were randomized; 40 to tenecteplase and 43 to placebo. The trial was terminated prematurely. Within 5 days, adverse outcomes occurred in three placebo-treated patients (death in one and intubation in two) and one tenecteplase-treated patient (fatal intracranial hemorrhage). At 90 days, adverse outcomes occurred in 13 unique placebo-treated patients and five unique tenecteplase-treated patients Thus, 16 (37%) placebo-treated and six (15%) tenecteplase-treated patients had at least one adverse outcome (exact two-sided P = 0.017). Conclusions: Treatment of patients with submassive pulmonary embolism with tenecteplase was associated with increased probability of a favorable composite outcome.

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.

Right ventricular (RV) failure occurs when the RV fails to maintain enough blood flow through the pulmonary circulation to achieve adequate left ventricular filling. This can occur suddenly in a previously healthy heart due to massive pulmonary embolism or right-sided myocardial infarction, but many cases encountered in the intensive care unit involve worsening of compensated RV failure in the setting of chronic heart and lung disease. Management of RV failure is directed at optimizing right-sided filling pressures and reducing afterload. Due to a lower level of vascular tone, vasoactive medications have less salient effects on reducing vascular resistance in the pulmonary than in the systemic circulation. Successful management requires reversal of any conditions that heighten pulmonary vascular tone and the use of selective pulmonary vasodilators at doses that do not induce systemic hypotension or worsening of oxygenation. Systemic systolic arterial pressure should be kept close to RV systolic pressure to maintain RV perfusion. When these efforts fail, the judicious use of inotropic agents may help improve RV contractility enough to maintain cardiac output. Extracorporeal life support is increasingly being used to support patients with acute RV failure who fail to respond to medical management while the underlying cause of their RV failure is addressed.

A proportion of pulmonary arterial hypertension (PAH) patients do not reach treatment goals with phosphodiesterase-5 inhibitors (PDE5i). RESPITE investigated the safety, feasibility and benefit of switching from PDE5i to riociguat in these patients.RESPITE was a 24-week, open-label, multicentre, uncontrolled study. Patients in World Health Organization (WHO) functional class (FC) III, with 6-min walking distance (6MWD) 165–440 m, cardiac index <3.0 L·min−1·m−2 and pulmonary vascular resistance >400 dyn·s·cm−5 underwent a 1–3 day PDE5i treatment-free period before receiving riociguat adjusted up to 2.5 mg maximum t.i.d. Exploratory end-points included change in 6MWD, WHO FC, N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and safety.Of 61 patients enrolled, 51 (84%) completed RESPITE. 50 (82%) were receiving concomitant endothelin receptor antagonists. At week 24, mean±sd 6MWD had increased by 31±63 m, NT-proBNP decreased by 347±1235 pg·mL−1 and WHO FC improved in 28 patients (54%). 32 patients (52%) experienced study drug-related adverse events and 10 (16%) experienced serious adverse events (2 (3%) study drug-related, none during the PDE5i treatment-free period). Six patients (10%) experienced clinical worsening, including death in two (not study drug-related).In conclusion, selected patients with PAH may benefit from switching from PDE5i to riociguat, but this strategy needs to be further studied.

Nitric oxide (NO) signaling plays a major role in modulating vascular tone and remodeling in the pulmonary circulation, but its role in the pathogenesis of pulmonary vascular diseases is still not completely understood. Numerous abnormalities of NO synthesis and signaling have been identified in animal models of pulmonary vascular disease and in humans with pulmonary hypertension. Many of these abnormalities have become targets of new therapies for the treatment of pulmonary hypertension. However, it is unclear to what extent alterations in NO signaling contribute to pulmonary hypertensive responses or merely reflect abnormalities induced by the underlying disease. This perspective examines the current understanding of altered NO signaling in pulmonary hypertensive diseases and discusses how these alterations may contribute to the pathogenesis of pulmonary hypertension. The efficacy and limitations of presently available therapies for pulmonary hypertension that target NO signaling are reviewed along with an update on investigational therapies that use this pathway to reverse pulmonary hypertensive changes.

Summary Background Rare genetic variants cause pulmonary arterial hypertension, but the contribution of common genetic variation to disease risk and natural history is poorly characterised. We tested for genome-wide association for pulmonary arterial hypertension in large international cohorts and assessed the contribution of associated regions to outcomes. Methods We did two separate genome-wide association studies (GWAS) and a meta-analysis of pulmonary arterial hypertension. These GWAS used data from four international case-control studies across 11 744 individuals with European ancestry (including 2085 patients). One GWAS used genotypes from 5895 whole-genome sequences and the other GWAS used genotyping array data from an additional 5849 individuals. Cross-validation of loci reaching genome-wide significance was sought by meta-analysis. Conditional analysis corrected for the most significant variants at each locus was used to resolve signals for multiple associations. We functionally annotated associated variants and tested associations with duration of survival. All-cause mortality was the primary endpoint in survival analyses. Findings A locus near SOX17 (rs10103692, odds ratio 1·80 [95% CI 1·55–2·08], p=5·13 × 10 –15 ) and a second locus in HLA-DPA1 and HLA-DPB1 (collectively referred to as HLA-DPA1/DPB1 here; rs2856830, 1·56 [1·42–1·71], p=7·65 × 10 –20 ) within the class II MHC region were associated with pulmonary arterial hypertension. The SOX17 locus had two independent signals associated with pulmonary arterial hypertension (rs13266183, 1·36 [1·25–1·48], p=1·69 × 10 –12 ; and rs10103692). Functional and epigenomic data indicate that the risk variants near SOX17 alter gene regulation via an enhancer active in endothelial cells. Pulmonary arterial hypertension risk variants determined haplotype-specific enhancer activity, and CRISPR-mediated inhibition of the enhancer reduced SOX17 expression. The HLA-DPA1/DPB1 rs2856830 genotype was strongly associated with survival. Median survival from diagnosis in patients with pulmonary arterial hypertension with the C/C homozygous genotype was double (13·50 years [95% CI 12·07 to >13·50]) that of those with the T/T genotype (6·97 years [6·02–8·05]), despite similar baseline disease severity. Interpretation This is the first study to report that common genetic variation at loci in an enhancer near SOX17 and in HLA-DPA1/DPB1 is associated with pulmonary arterial hypertension. Impairment of SOX17 function might be more common in pulmonary arterial hypertension than suggested by rare mutations in ...