A multiscale model of vascular function in chronic thromboembolic pulmonary hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH) is caused by recurrent or unresolved pulmonary thromboemboli, leading to perfusion defects and increased arterial wave reflections. CTEPH treatment aims to reduce pulmonary arterial pressure and reestablish adequate lung perfusion, yet patients with distal lesions are inoperable by standard surgical intervention. Instead, these patients undergo balloon pulmonary angioplasty (BPA), a multisession, minimally invasive surgery that disrupts the thromboembolic material within the vessel lumen using a catheter balloon. However, there still lacks an integrative, holistic tool for identifying optimal target lesions for treatment. To address this insufficiency, we simulate CTEPH hemodynamics and BPA therapy using a multiscale fluid dynamics model. The large pulmonary arterial geometry is derived from a computed tomography (CT) image, whereas a fractal tree represents the small vessels. We model ring- and web-like lesions, common in CTEPH, and simulate normotensive conditions and four CTEPH disease scenarios; the latter includes both large artery lesions and vascular remodeling. BPA therapy is simulated by simultaneously reducing lesion severity in three locations. Our predictions mimic severe CTEPH, manifested by an increase in mean proximal pulmonary arterial pressure above 20 mmHg and prominent wave reflections. Both flow and pressure decrease in vessels distal to the lesions and increase in unobstructed vascular regions. We use the main pulmonary artery (MPA) pressure, a wave reflection index, and a measure of flow heterogeneity to select optimal target lesions for BPA. In summary, this study provides a multiscale, image-to-hemodynamics pipeline for BPA therapy planning for patients with inoperable CTEPH. NEW & NOTEWORTHY This article presents novel computational framework for predicting pulmonary hemodynamics in chronic thromboembolic pulmonary hypertension. The mathematical model is used to identify the optimal target lesions for balloon pulmonary angioplasty, combining simulated pulmonary artery pressure, wave intensity analysis, and a new quantitative metric of flow heterogeneity.

Results of an Expert Consensus Survey on the Treatment of Pulmonary Arterial Hypertension With Oral Prostacyclin Pathway Agents.

BACKGROUND: Treatment of pulmonary arterial hypertension (PAH) has evolved substantially over the past two decades and varies according to etiology, functional class (FC), hemodynamic parameters, and other clinical factors. Current guidelines do not provide definitive recommendations regarding the use of oral prostacyclin pathway agents (PPAs) in PAH. To provide guidance on the use of these agents, an expert panel was convened to develop consensus statements for the initiation of oral PPAs in adults with PAH. METHODS: A systematic literature search was conducted using MEDLINE. The established RAND/University of California Los Angeles appropriateness method, which incorporates the Delphi method and the nominal group technique, was used to create consensus statements. Idiopathic, heritable, repaired congenital heart defect, and drug- or toxin-induced PAH (IPAH+) was considered as one etiologic grouping. The process was focused on the use of oral treprostinil or selexipag in patients with IPAH+ or connective tissue disease-associated PAH and FC II or III symptoms receiving background dual endothelin receptor antagonist/phosphodiesterase type 5 inhibitor therapy. RESULTS: The panel developed 14 consensus statements regarding the appropriate use of oral PPAs in the target population. The panel identified 13 clinical scenarios in which selexipag may be considered as a treatment option. CONCLUSIONS: The paucity of clinical evidence overall, and particularly from randomized trials in this setting, creates a gap in knowledge. These consensus statements are intended to aid physicians in navigating treatment options and using oral PPAs in the most appropriate manner in patients with PAH.

The cardiovascular patient's perceptions of complementary and alternative medicine.

BACKGROUND: Complementary and alternative medicine (CAM) use is common among patients with cardiovascular disorders and is generally underrecognized by physicians. The attitudes of these patients regarding these therapies and their perceptions of safety and efficacy have not been well defined. METHODS: A written survey was received from a cohort of outpatients seen at a large outpatient cardiovascular clinic in Texas. Over 75% of patients responded, with more than 90% of returned surveys adequate for analysis. RESULTS: Of the 210 respondents 113 admitted to CAM use, with Vitamins E and C being the most frequently utilized agents. Women were significantly more likely to take CAM than men (69 vs. 46%, p = 0.002), particularly those taking hormone replacement therapy. Over half of patients surveyed stated their cardiologist was unaware of their use of CAM. Only 15% of patients felt that CAM was more efficacious than their traditional medications, but almost half felt it was significantly safer. A similar number were unaware of any interactions between CAM and their other medications. CONCLUSIONS: Use of CAM is common in cardiology outpatients, and many patients remain unaware of potential health risks. Physicians should routinely question patients about use of CAM and attempt to educate users regarding potential health risks.