Clinical Phenotype and Outcomes of Pulmonary Hypertension Associated with Myeloproliferative Neoplasms: A Population-based Study.

Rationale: Precapillary pulmonary hypertension (PH) is a rare and largely unrecognized complication of myeloproliferative neoplasms (MPNs), including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (MF). Objectives: To describe characteristics and outcomes of MPN-associated PH. Methods: We report clinical, functional, and hemodynamic characteristics, classification, and outcomes of patients with PV, ET, or primary MF in the French PH registry. Measurements and Main Results: Ninety patients with MPN (42 PV, 35 ET, 13 primary MF) presented with precapillary PH with severe hemodynamic impairment, with a median mean pulmonary arterial pressure and pulmonary vascular resistance of 42 mm Hg and 6.7 Wood units, respectively, and impaired clinical conditions, with 71% in New York Heart Association functional classes III/IV and having a median 6-minute-walk distance of 310 m. Half of the patients were diagnosed with chronic thromboembolic PH (CTEPH); the other half were considered to have group 5 PH. MF was preferentially associated with group 5 PH, whereas PV and ET were generally related to CTEPH. Proximal lesions were diagnosed in half of the patients with CTEPH. Thromboendarterectomy was performed in 18 selected patients with high risk of complications (5 early deaths). Overall survival at 1, 3, and 5 years was 67%, 50%, and 34% in group 5 PH and 81%, 66%, and 42% in CTEPH, respectively. Conclusions: PH is a life-threatening condition potentially occurring in MPN. There are multiple mechanisms, with equal diagnoses of CTEPH and group 5 PH. Physicians should be aware that PH strongly affects the burden of patients with MPN, especially in group 5 PH, with unknown pathophysiological mechanisms.

Chronic thromboembolic pulmonary hypertension: the magic of pathophysiology.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare and underdiagnosed complication of acute pulmonary embolism (APE). CTEPH is a common cause of pulmonary hypertension (PH) with distinct management strategy including pulmonary endarterectomy, balloon pulmonary angioplasty, long-term anticoagulation and PH drugs targeting endothelial cell dysfunction. Initially, PH in chronic thromboembolic pulmonary disease (CTEPD) was thought to be due exclusively to the intravascular obstruction of pulmonary arteries by unresolved fibrotic clots. However, it is now well accepted that pulmonary vascular remodelling can include significant pulmonary microvasculopathy, which plays a role in the development of CTEPH. The histological description and clinical consequences of CTEPH microvasculopathy are now better understood. These lesions may involve not only small muscular pulmonary arteries <500 µm, but also pulmonary capillaries and veins. In addition, enlargement and proliferation of systemic bronchial arteries as well as anastomoses between the systemic and pulmonary circulations contribute to the development of microvasculopathy. In this review, we discuss the recent advances in the understanding of the pathophysiology of CTEPH.

Pulmonary thromboendarterectomy: The Marie Lannelongue Hospital experience.

Background: Targeted medical therapy and balloon pulmonary angioplasty (BPA) entered the field of chronic thromboembolic pulmonary hypertension (CTEPH) treatment in the early 2010's. Multimodal therapy is emerging as the new gold standard for CTEPH management. Whether this change of paradigm impacted early outcomes of pulmonary endarterectomy (PEA) remains unknown. Our aim is to report our surgical experience in the era of CTEPH multimodal management. Methods: Patients who underwent PEA between 2016 and 2020 were included in the study. Early outcomes were described and compared between three groups of patients: PEA alone, PEA after targeted medical therapy induction and PEA after BPA. Results: A total of 418 patients, 225 males and 193 females, with a mean age of 59±14 years were included in the study. 336 patients underwent PEA alone, 69 after medical targeted therapy induction and 13 after unilateral BPA. Baseline preoperative pulmonary vascular resistance [4.99 (IQR, 1.71-8.48), 6.21 (IQR, 4.37-8.1), 5.03 (IQR, 4.44-7.19) wood units (WU), P=0.230, respectively] and PEA effectiveness [% decrease mean pulmonary artery pressure (mPAP), 24 (IQR, 7-42), 25 (IQR, 7-35), 23 (IQR, 3-29), P=0.580] did not differ between groups. Compared to PEA alone and PEA+BPA, the medical therapy induction group represented the most challenging group with higher baseline mPAP (45±10 vs. 42±11 and 43±11 mmHg, P=0.047), longer circulatory arrest time (30.1±15 vs. 26.6±10 and 19.6±6 min, P=0.005), higher post-PEA extracorporeal membrane oxygenation use (20.6% vs. 8.7 and 9.1%, P=0.004), higher duration on mechanical ventilation [4 (IQR, 1-12) vs. 1 (IQR, 0.5-5) and 2 (IQR, 1-3) days, P=0.005], higher complication rate (85.5% vs. 74.6% and 76.9%, P=0.052) and higher 90-day mortality (13% vs. 3.9% and 0%, P=0.002). Compared to PEA and PEA+ medical therapy induction groups, patients in the BPA induction group were older [72 (IQR, 62-76) vs. 60 (IQR, 48-69) and 62 (IQR, 52-72) years, P=0.005], and underwent shorter cardiopulmonary bypass (191.9±47.9 vs. 222±107.2 and 236.8±46.4 min, P<0.001), aortic cross clamping (54.8±21 vs. 82.7±31.4 and 80.1±32.9 min, P=0.002) and circulatory arrest time (19.6±6.2 vs. 26.6±10.8 and 30.1±15.1 min, P=0.008). Conclusions: Multimodal therapy approach to CTEPH patients did not affect effectiveness of PEA. Medical therapy and BPA could act in synergy with surgery to treat more challenging patients.

ERS statement on chronic thromboembolic pulmonary hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism, either symptomatic or not. The occlusion of proximal pulmonary arteries by fibrotic intravascular material, in combination with a secondary microvasculopathy of vessels <500 µm, leads to increased pulmonary vascular resistance and progressive right heart failure. The mechanism responsible for the transformation of red clots into fibrotic material remnants has not yet been elucidated. In patients with pulmonary hypertension, the diagnosis is suspected when a ventilation/perfusion lung scan shows mismatched perfusion defects, and confirmed by right heart catheterisation and vascular imaging. Today, in addition to lifelong anticoagulation, treatment modalities include surgery, angioplasty and medical treatment according to the localisation and characteristics of the lesions.This statement outlines a review of the literature and current practice concerning diagnosis and management of CTEPH. It covers the definitions, diagnosis, epidemiology, follow-up after acute pulmonary embolism, pathophysiology, treatment by pulmonary endarterectomy, balloon pulmonary angioplasty, drugs and their combination, rehabilitation and new lines of research in CTEPH.It represents the first collaboration of the European Respiratory Society, the International CTEPH Association and the European Reference Network-Lung in the pulmonary hypertension domain. The statement summarises current knowledge, but does not make formal recommendations for clinical practice.

Phenotype and Outcomes of Pulmonary Hypertension Associated with Neurofibromatosis Type 1.

Rationale: Pulmonary hypertension (PH) associated with neurofibromatosis type 1 (NF1) is a rare and largely unknown complication of NF1.Objectives: To describe characteristics and outcomes of PH-NF1.Methods: We reported the clinical, functional, radiologic, histologic, and hemodynamic characteristics, response to pulmonary arterial hypertension (PAH)-approved drugs, and transplant-free survival of patients with PH-NF1 from the French PH registry.Measurements and Main Results: We identified 49 PH-NF1 cases, characterized by a female/male ratio of 3.9 and a median (minimum-maximum) age at diagnosis of 62 (18-82) years. At diagnosis, 92% were in New York Heart Association functional class III or IV. The 6-minute-walk distance was 211 (0-460) m. Pulmonary function tests showed low DlCO (30% [12-79%]) and severe hypoxemia (PaO2 56 [38-99] mm Hg). Right heart catheterization showed severe precapillary PH with a mean pulmonary artery pressure of 45 (10) mm Hg and a pulmonary vascular resistance of 10.7 (4.2) Wood units. High-resolution computed tomography images revealed cysts (76%), ground-glass opacities (73%), emphysema (49%), and reticulations (39%). Forty patients received PAH-approved drugs with a significant improvement in functional class and hemodynamic parameters. Transplant-free survival at 1, 3, and 5 years was 87%, 54%, and 42%, respectively, and four patients were transplanted. Pathologic assessment showed nonspecific interstitial pneumonia and major pulmonary vascular remodeling.Conclusions: PH-NF1 is characterized by a female predominance, a low DlCO, and severe functional and hemodynamic impairment. Despite a potential benefit of PAH treatment, prognosis remains poor, and double-lung transplantation is an option for eligible patients.

Portopulmonary hypertension in the current era of pulmonary hypertension management.

BACKGROUND & AIMS: Long-term outcomes in portopulmonary hypertension (PoPH) are poorly studied in the current era of pulmonary hypertension management. We analysed the effect of pulmonary arterial hypertension (PAH)-targeted therapies, survival and predictors of death in a large contemporary cohort of patients with PoPH. METHODS: Data from patients with PoPH consecutively enrolled in the French Pulmonary Hypertension Registry between 2007 and 2017 were collected. The effect of initial treatment strategies on functional class, exercise capacity and cardiopulmonary haemodynamics were analysed. Survival and its association with PAH- and hepatic-related characteristics were also examined. RESULTS: Six hundred and thirty-seven patients (mean age 55 ± 10 years; 58% male) were included. Fifty-seven percent had mild cirrhosis, i.e. Child-Pugh stage A. The median model for end-stage liver disease (MELD) score was 11 (IQR 9-15). Most patients (n = 474; 74%) were initiated on monotherapy, either with a phosphodiesterase-5 inhibitor (n = 336) or with an endothelin-receptor antagonist (n = 128); 95 (15%) were initiated on double oral combination therapy and 5 (1%) on triple therapy. After a median treatment time of 4.5 months, there were significant improvements in functional class (p <0.001), 6-minute walk distance (6MWD) (p <0.0001) and pulmonary vascular resistance (p <0.0001). Overall survival rates were 84%, 69% and 51% at 1, 3 and 5 years, respectively. Baseline 6MWD, sex, age and MELD score or Child-Pugh stage were identified as independent prognostic factors. Survival from PoPH diagnosis was significantly better in the subgroup of patients who underwent liver transplantation (92%, 83% and 81% at 1, 3 and 5 years, respectively). CONCLUSION: Survival of patients with PoPH is strongly associated with the severity of liver disease. Patients who underwent liver transplantation had the best long-term outcomes. LAY SUMMARY: Portopulmonary hypertension is defined by the presence of pulmonary arterial hypertension in the context of chronic liver disease and is characterized by progressive shortness of breath and exercise limitation. The presence of severe pulmonary arterial hypertension in liver transplant candidates represents a contraindication for such a surgery; however, treatments targeting pulmonary arterial hypertension are efficacious, allowing for safe transplantation and conferring good survival outcomes in those who undergo liver transplantation.

Comparison of Human and Experimental Pulmonary Veno-Occlusive Disease.

Pulmonary veno-occlusive disease (PVOD) occurs in humans either as a heritable form (hPVOD) due to biallelic inactivating mutations of EIF2AK4 (encoding GCN2) or as a sporadic form in older age (sPVOD). The chemotherapeutic agent mitomycin C (MMC) is a potent inducer of PVOD in humans and in rats (MMC-PVOD). Here, we compared human hPVOD and sPVOD, and MMC-PVOD pathophysiology at the histological, cellular, and molecular levels to unravel common altered pathomechanisms. MMC exposure in rats was associated primarily with arterial and microvessel remodeling, and secondarily by venous remodeling, when PVOD became symptomatic. In all forms of PVOD tested, there was convergent GCN2-dependent but eIF2α-independent pulmonary protein overexpression of HO-1 (heme oxygenase 1) and CHOP (CCAAT-enhancer-binding protein [C/EBP] homologous protein), two downstream effectors of GCN2 signaling and endoplasmic reticulum stress. In human PVOD samples, CHOP immunohistochemical staining mainly labeled endothelial cells in remodeled veins and arteries. Strong HO-1 staining was observed only within capillary hemangiomatosis foci, where intense microvascular proliferation occurs. HO-1 and CHOP stainings were not observed in control and pulmonary arterial hypertension lung tissues, supporting the specificity for CHOP and HO-1 involvement in PVOD pathobiology. In vivo loss of GCN2 (EIF2AK4 mutations carriers and Eif2ak4-/- rats) or in vitro GCN2 inhibition in cultured pulmonary artery endothelial cells using pharmacological and siRNA approaches demonstrated that GCN2 loss of function negatively regulates BMP (bone morphogenetic protein)-dependent SMAD1/5/9 signaling. Exogenous BMP9 was still able to reverse GCN2 inhibition-induced proliferation of pulmonary artery endothelial cells. In conclusion, we identified CHOP and HO-1 inhibition, and BMP9, as potential therapeutic options for PVOD.

Phenotype and outcome of pulmonary arterial hypertension patients carrying a TBX4 mutation.

INTRODUCTION: TBX4 mutation causes small patella syndrome (SPS) and/or pulmonary arterial hypertension (PAH). The characteristics and outcomes of PAH associated with TBX4 mutations are largely unknown. METHODS: We report the clinical, functional, radiologic, histologic and haemodynamic characteristics and outcomes of heritable PAH patients carrying a TBX4 mutation from the French pulmonary hypertension (PH) network. RESULTS: 20 patients were identified in 17 families. They were characterised by a median age at diagnosis of 29 years (0-76 years) and a female to male ratio of three. Most of the patients (70%) were in New York Heart Association (NYHA) functional class III or IV with a severe haemodynamic impairment (median pulmonary vascular resistance (PVR) of 13.6 (6.2-41.8) Wood units). Skeletal signs of SPS were present in 80% of cases. Half of the patients had mild restrictive or obstructive limitation and diffusing capacity of the lung for carbon monoxide (D LCO) was decreased in all patients. High-resolution computed tomography (HRCT) showed bronchial abnormalities, peri-bronchial cysts, mosaic distribution and mediastinal lymphadenopathies. PAH therapy was associated with significant clinical improvement. At follow-up (median 76 months), two patients had died and two had undergone lung transplantation. One-year, three-year and five-year event-free survival rates were 100%, 94% and 83%, respectively. Histologic examination of explanted lungs revealed alveolar growth abnormalities, major pulmonary vascular remodelling similar to that observed in idiopathic pulmonary arterial hypertension (IPAH) and accumulation of cholesterol crystals within the lung parenchyma. CONCLUSION: PAH due to TBX4 mutations may occur with or without skeletal abnormalities across a broad age range from birth to late adulthood. PAH is usually severe and associated with bronchial and parenchymal abnormalities.

Sex-specific differences in chronic thromboembolic pulmonary hypertension. Results from the European CTEPH registry.

BACKGROUND: Women are more susceptible than men to several forms of pulmonary hypertension, but have better survival. Sparse data are available on chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: We investigated sex-specific differences in the clinical presentation of CTEPH, performance of pulmonary endarterectomy (PEA), and survival. RESULTS: Women constituted one-half of the study population of the European CTEPH registry (N = 679) and were characterized by a lower prevalence of some cardiovascular risk factors, including prior acute coronary syndrome, smoking habit, and chronic obstructive pulmonary disease, but more prevalent obesity, cancer, and thyroid diseases. The median age was 62 (interquartile ratio, 50-73) years in women and 63 (interquartile ratio, 53-70) in men. Women underwent PEA less often than men (54% vs 65%), especially at low-volume centers (48% vs 61%), and were exposed to fewer additional cardiac procedures, notably coronary artery bypass graft surgery (0.5% vs 9.5%). The prevalence of specific reasons for not being operated, including patient's refusal and the proportion of proximal vs distal lesions, did not differ between sexes. A total of 57 (17.0%) deaths in women and 70 (20.7%) in men were recorded over long-term follow-up. Female sex was positively associated with long-term survival (adjusted hazard ratio, 0.66; 95% confidence interval, 0.46-0.94). Short-term mortality was identical in the two groups. CONCLUSIONS: Women with CTEPH underwent PEA less frequently than men, especially at low-volume centers. Furthermore, they had a lower prevalence of cardiovascular risk factors and were less often exposed to additional cardiac surgery procedures. Women had better long-term survival.

Haemodynamic definitions and updated clinical classification of pulmonary hypertension.

Since the 1st World Symposium on Pulmonary Hypertension (WSPH) in 1973, pulmonary hypertension (PH) has been arbitrarily defined as mean pulmonary arterial pressure (mPAP) ≥25 mmHg at rest, measured by right heart catheterisation. Recent data from normal subjects has shown that normal mPAP was 14.0±3.3 mmHg. Two standard deviations above this mean value would suggest mPAP >20 mmHg as above the upper limit of normal (above the 97.5th percentile). This definition is no longer arbitrary, but based on a scientific approach. However, this abnormal elevation of mPAP is not sufficient to define pulmonary vascular disease as it can be due to an increase in cardiac output or pulmonary arterial wedge pressure. Thus, this 6th WSPH Task Force proposes to include pulmonary vascular resistance ≥3 Wood Units in the definition of all forms of pre-capillary PH associated with mPAP >20 mmHg. Prospective trials are required to determine whether this PH population might benefit from specific management.Regarding clinical classification, the main Task Force changes were the inclusion in group 1 of a subgroup "pulmonary arterial hypertension (PAH) long-term responders to calcium channel blockers", due to the specific prognostic and management of these patients, and a subgroup "PAH with overt features of venous/capillaries (pulmonary veno-occlusive disease/pulmonary capillary haemangiomatosis) involvement", due to evidence suggesting a continuum between arterial, capillary and vein involvement in PAH.

Impact of the initiation of balloon pulmonary angioplasty program on referral of patients with chronic thromboembolic pulmonary hypertension to surgery.

BACKGROUND: Balloon pulmonary angioplasty (BPA) is a technique proposed for inoperable patients with chronic thromboembolic pulmonary hypertension (CTEPH). In this study we aimed to determine whether initiation of the BPA program has modified the characteristics and outcome of patients undergoing pulmonary endarterectomy (PEA), and compared the characteristics of patients undergoing one or the other procedure. METHODS: This prospective registry study included all patients with CTEPH who underwent PEA in the French National Reference Center before (2012 to 2013) and after (2015 to 2016) BPA program initiation (February 2014). Pre-operative clinical and hemodynamics profiles, peri-operative (Jamieson classification, surgery duration, need of assistance) characteristics of both groups, and all-cause mortality were compared using the t-test or chi-square test. Characteristics of patients subjected to surgery or BPA since February 2014 were also compared. RESULTS: The total number of patients referred to the CTEPH team increased in the BPA era (n = 291 vs n = 484). The pre-operative characteristics of patients from the pre-BPA era (n = 240) were similar to those from the BPA era (n = 246). Despite more Jamieson Type 3 cases (29%) in the second period, 30- and 90-day mortality remained stable (both p > 0.30). Patients subjected to BPA (n = 177) were older than those subjected to PEA (n = 364) (64 ± 14 vs 60 ± 14 years, respe`ctively), and had higher rates of splenectomy (10% vs 1%) or implantable port (9% vs 3%), lower total pulmonary resistance, better cardiac index, and better renal function (all p < 0.01). CONCLUSIONS: This study shows the influence of the initiation of the BPA program on the profile of patients with CTEPH undergoing PEA.

Design, Synthesis, and Biological Activity of New N-(Phenylmethyl)-benzoxazol-2-thiones as Macrophage Migration Inhibitory Factor (MIF) Antagonists: Efficacies in Experimental Pulmonary Hypertension.

Macrophage migration inhibitory factor (MIF) is a key pleiotropic mediator and a promising therapeutic target in cancer as well as in several inflammatory and cardiovascular diseases including pulmonary arterial hypertension (PAH). Here, a novel series of N-(phenylmethyl)-benzoxazol-2-thiones 5-32 designed to target the MIF tautomerase active site was synthesized and evaluated for its effects on cell survival. Investigation of structure-activity relationship (SAR) particularly at the 5-position of the benzoxazole core led to the identification of 31 that potently inhibits cell survival in DU-145 prostate cancer cells and pulmonary endothelial cells derived from patients with idiopathic PAH (iPAH-ECs), two cell lines for which survival is MIF-dependent. Molecular docking studies helped to interpret initial SAR related to MIF tautomerase inhibition and propose preferred binding mode for 31 within the MIF tautomerase active site. Interestingly, daily treatment with 31 started 2 weeks after a subcutaneous monocrotaline injection regressed established pulmonary hypertension in rats.

The changing landscape of chronic thromboembolic pulmonary hypertension management.

For patients with chronic thromboembolic pulmonary hypertension (CTEPH), the current standard of care involves surgical removal of fibro-thrombotic obstructions by pulmonary endarterectomy. While this approach has excellent outcomes, significant proportions of patients are not eligible for surgery or suffer from persistent/recurrent pulmonary hypertension after the procedure. The availability of balloon pulmonary angioplasty and the approval of the first medical therapy for use in CTEPH have significantly improved the outlook for patients ineligible for pulmonary endarterectomy. In this comprehensive review, we discuss the latest developments in the rapidly evolving field of CTEPH. These include improvements in imaging modalities and advances in surgical and interventional techniques, which have broadened the range of patients who may benefit from such procedures. The efficacy and safety of targeted medical therapies in CTEPH patients are also discussed, particularly the encouraging data from the recent MERIT-1 trial, which demonstrated the beneficial impact of using macitentan to treat patients with inoperable CTEPH, including those on background therapy. As the treatment options for CTEPH improve, hybrid management involving more than one intervention in the same patient may become a viable option in the near future.

Long-term outcomes of dasatinib-induced pulmonary arterial hypertension: a population-based study.

This study aimed to describe the long-term outcomes of pulmonary arterial hypertension (PAH) induced by dasatinib.21 incident, right heart catheterisation-confirmed cases of dasatinib-induced PAH were identified from the French Pulmonary Hypertension Registry. Clinical and haemodynamic variables were compared from baseline to last follow-up (median (range) 24 (1-81) months).Median age was 52 years and 15 patients were female (71%). 19 patients received dasatinib for chronic myelogenous leukaemia for a median (range) duration of 42 (8-74) months before PAH diagnosis. No bone morphogenic protein receptor-2 (BMPR2) mutations were found in the 10 patients tested. Dasatinib was uniformly discontinued and 11 patients received PAH medications. Four patients died during follow-up. New York Heart Association functional class improved from 76% in class III/IV to 90% in class I/II (p<0.01). Median (range) 6-min walk distance improved from 306 (0-660) to 430 (165-635) m (p<0.01). Median (range) mean pulmonary arterial pressure improved from 45 (30-70) to 26 (17-50) mmHg (p<0.01) and pulmonary vascular resistance from 6.1 (3.2-27.3) to 2.6 (1.2-5.9) Wood units (p<0.01). Patients treated with PAH medications had worse baseline haemodynamics but similar long-term outcomes to untreated patients. PAH persisted in 37% of patients.Dasatinib-induced PAH frequently improves after discontinuation but persisted in over one-third of patients, therefore systematic follow-up is essential.

Impact of High-Priority Allocation on Lung and Heart-Lung Transplantation for Pulmonary Hypertension.

BACKGROUND: Since 2006 and 2007, patients in France with severe pulmonary hypertension (PH) who are at imminent risk of death, despite optimal treatment in the intensive care unit, are placed on a high-priority list (HPL) for heart-lung transplantation (HLT) or double-lung transplantation (DLT). We assessed the effect of this approach on the waiting list and outcomes after transplantation. METHODS: We conducted a single-center, retrospective, before-and-after study of consecutive patients with severe group 1, 1', or 4 PH listed for DLT or HLT between 2000 and 2013 (ie, 6 years before and 6 years after HPL implementation). RESULTS: We included 234 patients. HPL implementation resulted in a significant decrease of the cumulative incidence of death on the waiting list at 1 and 2 years (p < 0.0001). The cumulative incidence of transplantation increased significantly from 48% to 76% after 2 years (p < 0.0001). Overall survival after transplantation was not significantly different between the pre-HPL and post-HPL era. In the HPL period, patients on the regular list who received a transplant had a nonsignificant trend toward improved overall survival compared with those on the HPL who received a transplant (at 1, 2, 3, and 5 years: 85%, 77%, 72%, and 72% vs 67%, 61%, 58%, and 50%; p = 0.053). Finally, survival after listing improved significantly after HPL implementation (at 1, 2, 3, and 5 years: 69%, 62%, 58%, and 54% vs 54%, 45%, 34%, and 26% before the HPL; p < 0.001). CONCLUSIONS: HPL implementation was followed by higher survival of PH patients after registration on the DLT or HLT waiting list and by a higher cumulative incidence of transplantation among waiting-list patients.

Clinical phenotypes and outcomes of heritable and sporadic pulmonary veno-occlusive disease: a population-based study.

BACKGROUND: Bi-allelic mutations of the EIF2AK4 gene cause heritable pulmonary veno-occlusive disease and/or pulmonary capillary haemangiomatosis (PVOD/PCH). We aimed to assess the effect of EIF2AK4 mutations on the clinical phenotypes and outcomes of PVOD/PCH. METHODS: We did a population-based study using clinical, functional, and haemodynamic data from the registry of the French Pulmonary Hypertension Network. We reviewed the clinical data and outcomes from all patients referred to the French Referral Centre (Pulmonary Department, Hospital Kremlin-Bicêtre, University Paris-Sud) with either confirmed or highly probable PVOD/PCH with DNA available for mutation screening (excluding patients with other risk factors of pulmonary hypertension, such as chronic respiratory diseases). We sequenced the coding sequence and intronic junctions of the EIF2AK4 gene, and compared clinical characteristics and outcomes between EIF2AK4 mutation carriers and non-carriers. Medical therapies approved for pulmonary arterial hypertension (prostacyclin derivatives, endothelin receptor antagonists and phosphodiesterase type-5 inhibitors) were given to patients according to the clinical judgment and discretion of treating physicians. The primary outcome was the event-free survival (death or transplantation). Secondary outcomes included response to therapies for pulmonary arterial hypertension and survival after lung transplantation. A satisfactory clinical response to specific therapy for pulmonary arterial hypertension was defined by achieving New York Heart Association functional class I or II, a 6-min walk distance of more than 440 m, and a cardiac index greater than 2·5 L/min per m2 at the first reassessment after initiation of specific therapy for pulmonary arterial hypertension. FINDINGS: We obtained data from Jan 1, 2003, to June 1, 2016, and identified 94 patients with sporadic or heritable PVOD/PCH (confirmed or highly probable). 27 (29%) of these patients had bi-allelic EIF2AK4 mutations. PVOD/PCH due to EIF2AK4 mutations occurred from birth to age 50 years, and these patients were younger at presentation than non-carriers (median 26·0 years [range 0-50.3] vs 60·0 years [6·7-81·4] years; p<0·0001). At diagnosis, both mutations carriers and non-carriers had similarly severe precapillary pulmonary hypertension and functional impairment. 22 (81%) of mutations carriers and 63 (94%) of non-carriers received therapy approved for pulmonary arterial hypertension. Drug-induced pulmonary oedema occurred in five (23%) of treated EIF2AK4 mutations carriers and 13 (21%) of treated non-carriers. Follow-up assessment after initiation of treatment showed that only three (4%) patients with PVOD/PCH reached the predefined criteria for satisfactory clinical response. The probabilities of event-free survival (death or transplantation) at 1 and 3 years were 63% and 32% in EIF2AK4 mutations carriers, and 75% and 34% in non-carriers. No significant differences occurred in event-free survival between the 2 groups (p=0·38). Among the 33 patients who had lung transplantation, estimated post-transplantation survival rates at 1, 2, and 5 years were 84%, 81%, and 73%, respectively. INTERPRETATION: Heritable PVOD/PCH due to bi-allelic EIF2AK4 mutations is characterised by a younger age at diagnosis but these patients display similar disease severity compared with mutation non-carriers. Response to therapy approved for pulmonary arterial hypertension in PVOD/PCH is rare. PVOD/PCH is a devastating condition and lung transplantation should be considered for eligible patients. FUNDING: None.

Dasatinib induces lung vascular toxicity and predisposes to pulmonary hypertension.

Pulmonary arterial hypertension (PAH) is a life-threatening disease that can be induced by dasatinib, a dual Src and BCR-ABL tyrosine kinase inhibitor that is used to treat chronic myelogenous leukemia (CML). Today, key questions remain regarding the mechanisms involved in the long-term development of dasatinib-induced PAH. Here, we demonstrated that chronic dasatinib therapy causes pulmonary endothelial damage in humans and rodents. We found that dasatinib treatment attenuated hypoxic pulmonary vasoconstriction responses and increased susceptibility to experimental pulmonary hypertension (PH) in rats, but these effects were absent in rats treated with imatinib, another BCR-ABL tyrosine kinase inhibitor. Furthermore, dasatinib treatment induced pulmonary endothelial cell apoptosis in a dose-dependent manner, while imatinib did not. Dasatinib treatment mediated endothelial cell dysfunction via increased production of ROS that was independent of Src family kinases. Consistent with these findings, we observed elevations in markers of endothelial dysfunction and vascular damage in the serum of CML patients who were treated with dasatinib, compared with CML patients treated with imatinib. Taken together, our findings indicate that dasatinib causes pulmonary vascular damage, induction of ER stress, and mitochondrial ROS production, which leads to increased susceptibility to PH development.

Quality of life in patients with chronic thromboembolic pulmonary hypertension.

Patients with chronic thromboembolic pulmonary hypertension (CTEPH) experience debilitating symptoms that have a negative impact on their quality of life (QoL) in terms of physical capability, psychological wellbeing and social relationships. The use of QoL measurement tools is important in the assessment of treatment efficacy and in guiding treatment decisions. However, despite the importance of QoL, particularly to the patient, it remains under-reported in clinical studies of CTEPH therapy. CTEPH is unique in pulmonary hypertension in that it is potentially curable by surgery; however, a proportion of patients either have residual PH following surgery or are not operable. Although some patients with CTEPH have been treated off-label with pulmonary arterial hypertension-specific therapies, there have been few randomised controlled trials of these therapies in patients with CTEPH. Moreover, in these trials QoL outcomes are variably assessed, and there is little consistency in the tools used. Here we review the assessment of QoL in patients with CTEPH and the tools that have been used. We also discuss the effect of surgical intervention and medical therapies on QoL. We conclude that further studies of QoL in patients with CTEPH are needed to further validate the optimal QoL tools.