Role of Optical Coherence Tomography in Vasculitis-Associated Pulmonary Hypertension and Chronic Thromboembolic Pulmonary Hypertension.

BACKGROUND: Identifying and understanding the microstructural changes within the wall of the pulmonary artery (PA) is crucial for elucidating disease mechanisms and guiding treatment strategies. We assessed the utility of optical coherence tomography (OCT) in identifying such changes within segmental/subsegmental PAs and compared the morphological variations in WHO group 4 pulmonary hypertension associated with Behcet Disease (BD), Takayasu arteritis (TA) and chronic thromboembolic pulmonary hypertension (CTEPH). Idiopathic pulmonary arterial hypertension (IPAH) patients served as controls.Methods and Results: A total of 197 cross-sectional images were analyzed from 20 consecutive patients. BD patients exhibited lower %wall area and mean wall thickness (MWT) compared with CTEPH, TA and, IPAH patients. TA patients showed a notably higher %wall area, which was significant in IPAH and BD patients. Variations in %wall area measurements were observed across distinct cross-sectional segments of the PA within individual patients (22% in CTEPH, 19% in BD, 16% in TA, 23% in IPAH patients). Intravascular webs, bands, and thrombi were observed in BD and CTEPH patients. OCT provided clear delineation of vascular wall calcifications and adventitial vasa vasorum. No procedure-related complications were observed. CONCLUSIONS: PA involvement differs among the various etiologies of PH, with the PA being heterogeneously affected. OCT offers promise in elucidating microstructural vascular wall changes and providing insights into disease mechanisms and treatment effects.

Diagnosis and Treatment Patterns of Chronic Thromboembolic Pulmonary Hypertension in Russia, Kazakhstan, Turkey, Lebanon, and Saudi Arabia: A Registry Study.

BACKGROUND: Patients with chronic thromboembolic pulmonary hypertension (CTEPH) in countries with limited resources have, to date, been poorly represented in registries. OBJECTIVE: This work assesses the epidemiology, diagnosis, hemodynamic and functional parameters, and treatment of CTEPH in Russia, Kazakhstan, Turkey, Lebanon, and Saudi Arabia. METHODS: A prospective, cohort, phase IV, observational registry with 3-year follow-up (n = 212) in patients aged ≥ 18 years diagnosed with CTEPH was created. Clinical, hemodynamic, and functional parameters were obtained at an initial visit, follow-up visits, and a final visit at the end of 3 years' observation or end of follow-up. Data were recorded on electronic case report forms. Parameters evaluated included 6-minute walking distance (6MWD), use of pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA), pulmonary hypertension (PH)-targeted therapy, and survival. All statistical analyses were exploratory and descriptive, and were performed in the overall population. RESULTS: The most common symptoms were typical of those expected for CTEPH. Almost 90% of patients underwent right heart catheterization at diagnosis or initial study visit. In total, 66 patients (31%) underwent PEA before the initial visit; 95 patients (45%) were considered operable, 115 (54%) were inoperable, and two (1%) had no operability data. Only 26 patients (12%) had been assessed for BPA at their initial visit. PH-targeted therapy was documented at diagnosis for 77 patients (36%), most commonly a phosphodiesterase type 5 inhibitor (23%). Use of PH-targeted therapy increased to 142 patients (67%) at the initial visit, remaining similar after 3 years. Use of riociguat increased from 6% of patients at diagnosis to 38% at 3 years. Between baseline and end of observation, results for patients with paired data showed an increase in 6MWD. Survival at the end of observation was 88%. CONCLUSIONS: These data highlight the current diagnosis and management of CTEPH in the participating countries. They show that early CTEPH diagnosis remains challenging, and use of off-label PH-targeted therapy is common. CLINICALTRIALS: gov: NCT02637050; registered December 2015.

Chronic thromboembolic pulmonary hypertension in patients with persistent chest symptoms after acute pulmonary embolism.

OBJECTIVE: This study aimed to analyze the role of chronic thromboembolic pulmonary hypertension (CTEPH) in patients with persistent chest symptoms after acute PE. METHODS: Patients aged between 18 and 80 years who were followed up for acute PE were screened for chest symptoms which persisted after the anticoagulation treatment. Patients suffering other types of pulmonary hypertension (PH) or metastatic malignancies were excluded in this study. Demographic and functional data of patients included this study were collected. The patients underwent transthoracic echocardiography and ventilation/perfusion (VQ) scans. Also, invasive hemodynamic studies were done to patients with intermediate/high probability of VQ scans. RESULTS: Of the 140 patients screen for this study, 29 patients (Female/Male=16/13) with mean age of 56.1±11.2 years and follow-up time of 35.1±17.7 months met the inclusion criteria. The mean systolic pulmonary artery blood pressure (sPAP) on transthoracic echocardiography was 28.9±4.9 mm Hg (range=20-40 mm Hg). Furthermore, intermediate or high probability of VQ scans was detected in 2 patients, who were subsequently diagnosed with CTEPH (6.9%) via right heart catheterization. CONCLUSION: CTEPH was diagnosed at a low rate in patients with persistent chest symptoms after the anticoagulation treatment for PE. CTEPH is still an elusive entity, which requires a multidisciplinary and invasive approach.

Gastrin-releasing peptide induces fibrotic response in MRC5s and proliferation in A549s.

Idiopathic pulmonary fibrosis (IPF) is a complex lung disease, whose build-up scar tissue is induced by several molecules. Gastrin-releasing peptide (GRP) is released from pulmonary neuroendocrine cells, alveolar macrophages, and some nerve endings in the lung. A possible role of GRP in IPF is unclear. We aimed to investigate the fibrotic response to GRP, at the cellular level in MRC5 and A549 cell lines. The proliferative and fibrotic effects of GRP on these cells were evaluated by using BrdU, immunoblotting, immunofluorescence and qRT-PCR for molecules associated with myofibroblast differentiation, TGF-ß and Wnt signalling. All doses of GRP increased the amount of BrdU incorporation in A549 cells. In contrast, the amount of BrdU increased in MRC5 cells in the first 24 h, though progressively decreased by 72 h. GRP did not stimulate epithelial-mesenchymal transition in A549 cells, rather, it stimulated the differentiation of MRC5 cells into myofibroblasts. Furthermore, GRP induced gene and protein expressions of p-Smad2/3 and Smad4, and reduced the levels of Smad7 in MRC5 cells. In addition, GRP decreased Wnt5a protein levels and stimulated ß-catenin activation by increasing Wnt4, Wnt7a and ß-catenin protein levels. GRP caused myofibroblast differentiation by inducing TGF-ßand Wnt pathways via paracrine and autocrine signalling in MRC5 cells. In conclusion, GRP may lead to pulmonary fibrosis due to its proliferative and fibrotic effects on lung fibroblasts. The abrogation of GRP-mediated signal activation might be considered as a treatment modality for fibrotic lung diseases. Video Abstract.

Assessment of atrial electromechanical delay and P wave dispersion in patients with chronic obstructive pulmonary disease.

OBJECTIVE: Chronic obstructive pulmonary disease (COPD) is associated with atrial fibrillation (AF) and reduced forced expiratory volume (FEV1) is an independent predictor for new onset AF. The aims of this study were (1) to analyze the atrial electromechanical delay (AEMD) and P wave dispersion which are two predictors of AF development in patients with COPD and without any cardiovascular disease, and (2) to assess the relationship of those with pulmonary functions as quantified by FEV1 measurements. METHODS: The study included 41 patients with COPD (33 male; mean age: 51 years) and 32 healthy controls. P wave dispersion was calculated as the difference between the maximum and minimum P wave duration in a 12-lead surface electrocardiography (ECG) recording. AEMD, defined as the time interval from the P wave onset on the ECG to the initiation of the late diastolic (Am) wave using a tissue Doppler examination, was measured from the lateral mitral annulus (LAEMD), septal annulus (SAEMD), and tricuspid lateral annulus (TAEMD). RESULTS: P wave dispersion was significantly longer in the COPD group than those in the controls (76±19 ms vs. 45±10 ms; p<0.001). All of the AEMD measurements demonstrated significant prolongation in patients with COPD (LAEMD: 74±9 ms vs. 64±11 ms; SAEMD: 66±10 ms vs. 57±12 ms; and TAEMD: 65±9 ms vs. 46±7 ms; p<0.001 for all). The only correlation with FEV1 was observed in the TAEMD values of the COPD group (rs: -401; p<0.009). CONCLUSION: Both P wave dispersion and AEMD parameters were significantly longer in COPD patients without any established structural or functional cardiac abnormalities, indicating an increased tendency for AF development, beginning from the initial stages of the disease.