Pulmonary Hypertension Lung Disease Research Articles

Severe pulmonary hypertension in lung disease: phenotypes and response to treatment.

Pulmonary hypertension (PH) due to lung disease (World Health Organization (WHO) group 3) is common, but severe PH, arbitrarily defined as mean pulmonary artery pressure ≥35 mmHg is reported in only a small proportion. Whether these should be treated as patients in WHO group 1 (i.e. pulmonary arterial hypertension) with PH-targeted therapies is unknown. We compared the phenotypic characteristics and outcomes of 118 incident patients with severe PH and lung disease with 74 idiopathic pulmonary arterial hypertension (IPAH) patients, all treated with pulmonary vasodilators. Lung disease patients were older, more hypoxaemic, and had lower gas transfer, worse New York Heart Association functional class and lower 6-min walking distance (6MWD) than IPAH patients. Poorer survival in those with lung disease was driven by the interstitial lung disease (ILD) cohort. In contrast to IPAH, where significant improvements in 6MWD and N-terminal pro-brain natruiretic peptide (NT-proBNP) occurred, PH therapy in severe PH lung disease did not lead to improvement in 6MWD or functional class, but neither was deterioration seen. NT-proBNP decreased from 2200 to 1596 pg·mL(-1) (p=0.015). Response varied by lung disease phenotype, with poorer outcomes in patients with ILD and emphysema with preserved forced expiratory volume in 1 s. Further study is required to investigate whether vasodilator therapy may delay disease progression in severe PH with lung disease.

Medical treatment of pulmonary hypertension: what's new?

Pulmonary hypertension (PH) is a chronic progressive disease of the pulmonary circulation of multifactorial causes. The current diagnostic classification of PH distinguishes five main groups, which have as a common feature an increased pulmonary arterial pressure and pulmonary resistance. The classification differentiates pulmonary arterial hypertension (PAH), PH due to left heart disease, PH in lung diseases and/or hypoxia, chronic thromboembolic pulmonary hypertension (CTEPH), and PH with unclear/multifactorial mechanisms. Recent advances in basic research with the approval of new drugs and the establishment of therapeutic strategies, mainly in PAH and CTEPH, require a differentiated view of the disease, a careful diagnosis and initiation of therapy, and regular follow-ups. In this article, we provide an overview of the complex drug therapy currently available for PAH patients.

MTOR and vascular remodeling in lung diseases: current challenges and therapeutic prospects

Mammalian target of rapamycin (mTOR) is a major regulator of cellular metabolism, proliferation, and survival that is implicated in various proliferative and metabolic diseases, including obesity, type 2 diabetes, hamartoma syndromes, and cancer. Emerging evidence suggests a potential critical role of mTOR signaling in pulmonary vascular remodeling. Remodeling of small pulmonary arteries due to increased proliferation, resistance to apoptosis, and altered metabolism of cells forming the pulmonary vascular wall is a key currently irreversible pathological feature of pulmonary hypertension, a progressive pulmonary vascular disorder with high morbidity and mortality. In addition to rare familial and idiopathic forms, pulmonary hypertension is also a life-threatening complication of several lung diseases associated with hypoxia. This review aims to summarize our current knowledge and recent advances in understanding the role of the mTOR pathway in pulmonary vascular remodeling, with a specific focus on the hypoxia component, a confirmed shared trigger of pulmonary hypertension in lung diseases. We also discuss the emerging role of mTOR as a promising therapeutic target and mTOR inhibitors as potential pharmacological approaches to treat pulmonary vascular remodeling in pulmonary hypertension.

Pulmonary hypertension in lung diseases: Survey of beliefs and practice patterns

Pulmonary hypertension can be associated with decreased functional capacity and poor prognosis in patients with parenchymal lung diseases (PLD). Yet, little attention has been given to current beliefs and practice patterns. An 18-question survey was submitted electronically to members of four Networks of the American College of Chest Physicians. Analyzable responses were received from 453 physicians. Most (95%) respondents reported testing for PH in patients with PLD using transthoracic echocardiography (TTE) or right-heart catheterization (RHC) and believed that PH could occur in the absence of severe compromise in pulmonary function (70%) and hypoxemia (50%). Approximately 30% of physicians reported not performing RHC to confirm a diagnosis of PH before initiating therapy. Most respondents (92%) felt that medical therapy was effective and the medication of first choice was either bosentan or sildenafil. Most respondents believed that treating PH in these patients improves quality of life (63%) and dyspnea (67%), but were less sure about the impact on functional capacity and survival. Approximately 30% of physicians do not perform RHC to confirm this diagnosis prior to initiating therapy. Despite relatively little supportive evidence, most physicians treat with vasoactive medications and believe that medical therapy confers benefit.

Inhalation of vasoactive intestinal peptide in pulmonary hypertension

Pulmonary hypertension (PH) leads to an increased right ventricular workload, cardiac failure and death. In idiopathic pulmonary arterial hypertension (PAH) the vasodilating vasoactive intestinal peptide (aviptadil) is deficient. The aim of the present study was to test the acute effects on haemodynamics and blood gases, and the safety, of a single dose of inhaled aviptadil in chronic PH. A total of 20 patients with PH (PAH in nine, PH in lung disease in eight and chronic thromboembolic PH in three) inhaled a single 100-microg dose of aviptadil during right-heart catheterisation. Haemodynamics and blood gases were measured. Aviptadil aerosol caused a small and temporary but significant selective pulmonary vasodilation, an improved stroke volume and mixed venous oxygen saturation. Overall, six patients experienced a pulmonary vascular resistance reduction of >20%. In patients with significant lung disease, aviptadil tended to improve oxygenation. The pulmonary vasodilating effect of aviptadil aerosol was modest and short-lived, did not cause any side-effects and led to a reduced workload of the right ventricle without affecting systemic blood pressure. Aviptadil inhalation tended to improve oxygenation in patients with significant lung disease. Further studies are needed to evaluate the full therapeutic potential of aviptadil aerosol, including higher doses and chronic treatment.

Large Animal Model of Chronic Pulmonary Hypertension

A large animal model is needed to study artificial lung attachment in a setting simulating chronic lung disease with significant pulmonary hypertension (PH). This study sought to create a sheep model that develops significant PH within 60 days with a low rate of mortality. Sephadex beads were injected in the pulmonary circulation of sheep every other day for 60 days at doses of 0.5, 0.75, and 1 g (n = 10, 10, 7). Mean pulmonary artery pressure, pulmonary capillary wedge pressure, and cardiac output were obtained every 2 weeks. In the 0.5, 0.75, and 1-g groups, 90, 70, and 14.3% of sheep completed the study, respectively, with the remainder experiencing heart failure. By the 60th day, pulmonary vascular resistance had increased (p < 0.01) from 0.89 +/- 0.3 to 3.2 +/- 0.9 mm Hg/(L/min) and from 0.9 +/- 0.3 to 4.3 +/- 3.2 mm Hg/(L/min) in the 0.5 and 0.75-g groups, respectively. Significant right ventricular hypertrophy was observed in the 0.75-g group but not in the 0.5-g group. Data from the 1-g group were insufficient for analysis due to high mortality. Thus, the 0.5 and 0.75-g groups generate significant PH, but the 0.75-g group is a better model of chronic PH in lung disease due to the development of right ventricular hypertrophy.

Extracardiac causes of right ventricular insufficiency

Evidence for manifest right ventricular dysfunction is considered a critical threshold in the development of a fatal event after acute pulmonary embolism. While the acute event impressively reflects the clinical significance of right ventricular function, various disorders such as idiopathic pulmonary arterial hypertension, secondary pulmonary hypertension in lung diseases, carcinoid heart disease, and portopulmonary hypertension can lead to chronic right ventricular failure. Adapted treatment makes it possible to alleviate the patients' distress and presumably also improve the prognosis. The clinical picture of right ventricular insufficiency can also be imitated in constrictive or adhesive pericarditis and pericardial tamponade. Pericardiocentesis of the tamponade provides initial hemodynamic improvement. Causal treatment is based on cytological findings and/or results of epicardial or pericardial biopsy to classify malignant and nonmalignant effusions. Cardiac surgery with pericardiolysis and (partial) pericardial resection remains the method of choice for symptomatic constrictive pericarditis.