Changing demographics, epidemiology, and survival of incident pulmonary arterial hypertension: results from the pulmonary hypertension registry of the United Kingdom and Ireland.

RATIONALE: Incident pulmonary arterial hypertension was underrepresented in most pulmonary hypertension registries and may have a different disease profile to prevalent disease. OBJECTIVES: To determine the characteristics and outcome of a purely incident, treatment-naive cohort of idiopathic, heritable, and anorexigen-associated pulmonary arterial hypertension and to determine the changes in presentations and survival over the past decade in the United Kingdom and Ireland. METHODS: All consecutive newly diagnosed patients from 2001 to 2009 were identified prospectively. MEASUREMENTS AND MAIN RESULTS: A total of 482 patients (93% idiopathic, 5% heritable, and 2% anorexigen-associated pulmonary arterial hypertension) were diagnosed, giving rise to an estimated incidence of 1.1 cases per million per year and prevalence of 6.6 cases per million in 2009. Younger patients (age ≤ 50 yrs) had shorter duration of symptoms, fewer comorbidities, better functional and exercise capacity, higher percent diffusing capacity of carbon monoxide, more severe hemodynamic impairment, but better survival compared with older patients. In comparison with the earlier cohorts, patients diagnosed in 2007-2009 were older, more obese, had lower percent diffusing capacity of carbon monoxide,(,) and more comorbidities, but better survival. Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management (REVEAL) equation, REVEAL risk score, and Pulmonary Hypertension Connection Registry survival equation accurately predicted survival of our incident cohort at 1 year. CONCLUSIONS: This study highlights the influence of age on phenotypes of incident pulmonary arterial hypertension and has shown the changes in demographics and epidemiology over the past decade in a national setting. The results suggest that there may be two subtypes of patients: the younger subtype with more severe hemodynamic impairment but better survival, compared with the older subtype who has more comorbidities.

How do I manage a patient with suspected acute pulmonary embolism?

Acute PE is a cardiovascular emergency and early risk stratification is important in the management of these patients. Pre-test clinical prediction models together with D-dimer assays help select those who require imaging. Each hospital should develop a strategy for investigating patients with suspected PE depending on local expertise, resources and the patient population.

Idiopathic pulmonary arterial hypertension and co-existing lung disease: is this a new phenotype?

Patients classified as idiopathic pulmonary arterial hypertension (defined as Group 1 on European Respiratory Society (ERS)/European Cardiac Society (ESC) criteria) may have evidence of minor co-existing lung disease on thoracic computed tomography. We hypothesised that these idiopathic pulmonary arterial hypertension patients (IPAH lung disease ) are a separate subgroup of idiopathic pulmonary arterial hypertension with different phenotype and outcome compared with idiopathic pulmonary arterial hypertension patients without co-existing lung disease (IPAH no lung disease ). Patients with 'IPAH lung disease ' have been eligible for all clinical trials of Group 1 patients because they have normal clinical examination and normal spirometry but we wondered whether they responded to treatment and had similar survival to patients with 'IPAH no lung disease '. We described the outcome of the cohort of patients with 'IPAH no lung disease ' in a previous paper. Here, we have compared incident 'IPAH lung disease ' patients with 'IPAH no lung disease ' patients diagnosed concurrently in all eight Pulmonary Hypertension centres in the UK and Ireland between 2001-2009. Compared with 'IPAH no lung disease ' (n = 355), 'IPAH lung disease ' patients (n = 137) were older, less obese, predominantly male, more likely to be current/ex-smokers and had lower six-minute walk distance, lower % predicted diffusion capacity for carbon monoxide, lower mean pulmonary arterial pressure and lower pulmonary vascular resistance index. After three months of pulmonary hypertension-targeted treatment, six-minute walk distance improved equally in 'IPAH lung disease ' and 'IPAH no lung disease '. However, survival of 'IPAH lung disease ' was lower than 'IPAH no lung disease ' (one year survival: 72% compared with 93%). This survival was significantly worse in 'IPAH lung disease ' even after adjusting for age, gender, smoking history, comorbidities and haemodynamics. 'IPAH lung disease ' patients had similar short-term improvement in six-minute walk distance with anti-pulmonary arterial hypertension therapy but worse survival compared with 'IPAH no lung disease ' patients. This suggests that 'IPAH lung disease ' are a separate phenotype and should not be lumped with 'IPAH no lung disease ' in clinical trials of Group 1 pulmonary arterial hypertension.

Survival in portopulmonary hypertension: Outcomes of the United Kingdom National Pulmonary Arterial Hypertension Registry.

BACKGROUND: Portopulmonary hypertension (PoPH) is a rare condition associated with poor survival, and the effect of modern therapies that target pulmonary arterial hypertension (PAH) on long-term outcome is unknown. This study investigated the baseline characteristics and survival in the cohort of patients diagnosed with PoPH in the United Kingdom National Pulmonary Hypertension Service. METHODS: A retrospective review was conducted of all incident treatment-naïve patients with PoPH within the United Kingdom national registry diagnosed between January 2001 and December 2010. RESULTS: Patients with PoPH (n = 110) had survival rates of 85%, 60%, and 35% at 1, 3, and 5 years. The prevalence of PoPH was 0.85 cases/1 million. Mean age at diagnosis was 53 ± 12 years, with a balanced distribution in gender. Alcohol (n = 57) and hepatitis C (n = 10) were the most common causes of portal hypertension. Phosphodiesterase V inhibitors were the most frequently used targeted therapy, in 63.6% (n = 70) of patients, endothelin receptor antagonists were used in 10% (n = 11) and prostacyclin analogs in 12.7% (n = 14). Univariate and multivariate analysis of baseline characteristics did not demonstrate a significant influence of severity of portal hypertension or liver cirrhosis, World Health Organization Functional Class, cardiopulmonary hemodynamics, or year of diagnosis on survival. CONCLUSIONS: Survival of patients with PoPH remains poor despite targeted therapy and worse than patients with idiopathic PAH. The benefit of PAH therapies in PoPH on long-term morbidity and mortality outcomes needs further consideration and study.

Differential effects of TGF-beta1 and BMP-4 on the hypoxic induction of cyclooxygenase-2 in human pulmonary artery smooth muscle cells.

Chronic hypoxia-induced pulmonary hypertension results partly from proliferation of smooth muscle cells in small peripheral pulmonary arteries. Previously, we demonstrated that hypoxia modulates the proliferation of human peripheral pulmonary artery smooth muscle cells (PASMCs) by induction of cyclooxygenase-2 (COX-2) and production of antiproliferative prostaglandins. The transforming growth factor (TGF)-beta superfamily plays a critical role in the regulation of pulmonary vascular remodeling, although to date an interaction with hypoxia has not been examined. We therefore investigated the pathways involved in the hypoxic induction of COX-2 in peripheral PASMCs and the contribution of TGF-beta1 and bone morphogenetic protein (BMP)-4 in this response. In the present study, we demonstrate that hypoxia induces activation of p38MAPK, ERK1/2, and Akt in PASMCs and that these pathways are involved in the hypoxic regulation of COX-2. Whereas inhibition of p38(MAPK) or ERK1/2 activity suppressed hypoxic induction of COX-2, inhibition of the phosphoinositide 3-kinase pathway enhanced hypoxic induction of COX-2. Furthermore, exogenous TGF-beta1 induced COX-2 mRNA and protein expression, and our findings demonstrate that release of TGF-beta1 by PASMCs during hypoxia contributes to the hypoxic induction of COX-2 via the p38MAPK pathway. In contrast, BMP-4 inhibited the hypoxic induction of COX-2 by an MAPK-independent pathway. Together, these findings suggest that the TGF-beta superfamily is part of an autocrine/paracrine system involved in the regulation of COX-2 expression in the distal pulmonary circulation, and this modulates hypoxia-induced pulmonary vascular cell proliferation.

Hypoxic induction of cox-2 regulates proliferation of human pulmonary artery smooth muscle cells.

Chronic hypoxia-induced pulmonary hypertension results partly from proliferation of smooth muscle cells in small peripheral pulmonary arteries. Therefore, we examined the effect of hypoxia on growth of pulmonary artery smooth muscle cells (PASMCs) from human distal pulmonary arteries. Initial studies identified that serum-induced proliferation of explant-derived PASMCs was inhibited under hypoxic conditions (3-4 kPa in medium). However, selection of hypoxia-stimulated cells was achieved by culturing cells at low density under conditions of prolonged hypoxia (1-2 wk). In hypoxia-inhibited and -stimulated cells, Western blotting revealed hypoxic induction of cyclooxygenase (COX)-2, which was dependent on the activation of p38(MAPK), but not COX-1, inducible nitric oxide synthase (iNOS), or hemoxygenase-1 (HO-1). Hypoxic induction of COX-2 was also observed in the media of pulmonary arteries in lung organ culture. Hypoxia induced a 4- to 5-fold increase (P < 0.001) in prostaglandin (PG)E(2), PGD(2), PGF(2alpha), and 6-keto-PGF(1alpha) release from PASMCs. Hypoxic inhibition of proliferation was attenuated by incubation with indomethacin (10 micro M), or the COX-2 antagonist, NS398 (10 micro M), but not by the COX-1 antagonist, valeryl salicylate (0.5 mM). In conclusion, we have isolated cells from human peripheral pulmonary arteries that are either inhibited or stimulated by culture under hypoxic conditions. In both cell types hypoxia modulates cell proliferation by induction of COX-2 and production of antiproliferative prostaglandins. Induction of COX-2 may contribute to the inhibition of hypoxia-induced pulmonary vascular remodeling.