Treatment of patients with chronic thrombo embolic pulmonary hypertension: focus on riociguat

Preoperative Management of Gastrointestinal and Pulmonary Medications: Society for Perioperative Assessment and Quality Improvement (SPAQI) Consensus Statement

Perioperative medication management is integral to preoperative optimization but remains challenging because of a paucity of literature guidance. Published recommendations are based on the expert opinion of a small number of authors without collaboration from multiple specialties. The Society for Perioperative Assessment and Quality Improvement (SPAQI) recognized the need for consensus recommendations in this area as well as the unique opportunity for its multidisciplinary membership to fill this void. In a series of articles within this journal, SPAQI provides preoperative medication management guidance based on available literature and expert multidisciplinary consensus. The aim of this consensus statement is to provide practical guidance on the preoperative management of gastrointestinal and pulmonary medications. A panel of experts with anesthesiology, perioperative medicine, hospital medicine, general internal medicine, and medical specialty experience was drawn together and identified the common medications in each of these categories. The authors then used a modified Delphi approach to review the literature and to generate consensus recommendations.

The role of inflammation in a rat model of chronic thromboembolic pulmonary hypertension induced by carrageenan

Background

Chronic thromboembolic pulmonary hypertension (CTEPH) is a life-threatening condition arising from the thrombus and obstructive remodeling of the pulmonary arteries, which causes a significant morbidity and mortality. Although the modern treatment in CTEPH has been significant advanced both in surgical and medical treatment, none can claim to cure the disease, largely because of our limited understanding of the underlying pathogenesis of the disease and lack of a reliable CTEPH animal model to study for. Recently, inflammation has been accepted as a common pathway through which various risk factors trigger venous thrombo-embolism (VTE) formation, we describe a novel mouse model of CTEPH which reproduces a frequent trigger and resembles the time course, histological features, and clinical presentation of CTEPH in humans, to open a new horizons of inflammation in CTEPH.

Methods

By administering a pulmonary embolism (PE) protocol (comprising 3 sequential left jugular vein injections of autologous blood clots) to 8-week-old male Sprague Dawley (SD) rats using tranexamic acid (200 mg/kg^.d) to inhibit fibrinolysis and injecting additional carrageenan (20 mg/kg, once a week) to create perivascular inflammation, we successfully generated a CTEPH animal model. By monitoring the mean pulmonary artery pressure (mPAP) and the histopathological change to evaluate the CTEPH model. By detecting the RT-PCR, western blot, TUNEL, and immunohistochemistry in the sub-groups to find the potential mechanism of inflammation may work in the pulmonary vascular remolding.

Results

In this study, rats with CTEPH exhibited pronounced pulmonary vascular remolding with higher vessel wall area/total area (WA/TA) ratio in comparison to the control rats (85.41%±7.37% vs. 76.41%±5.97%, P<0.05), the mPAP (25.51±1.13 vs. 15.92±1.13 mmHg, P<0.05). Significant differences in mean pulmonary artery pressure (mPAP) values were observed between rats injected solely with clots and those injected with both clots and carrageenan (25.51±1.13 vs. 29.82±1.26 mmHg, P<0.05, respectively). Furthermore, following the third embolization, thrombi and intimal hyperplasia occurred in the pulmonary artery. In addition, repeated embolization elevated mRNA and protein levels of tumor necrosis factor-α (TNF-α), NF-κB/p65, and B-cell lymphoma-2 (BCL-2), but decreased BAX expression in a time-dependent manner.

Conclusions

Take advantage of the inflammation to trigger VTE formation, we successfully generated a CTEPH animal model. Inflammation may play a crucial role in the pathogenesis and progression of CTEPH by inhibiting endothelial cell apoptosis. Understanding the role of inflammation in CTEPH may not only help to determine the optimal treatment options but also may aid in the development of future preventative strategies, since current anticoagulation treatment regimens are not designed to inhibit inflammation.

Pulmonary hypertension associated with antiphospholipid antibody: Call for a screening tool?

Antiphospholipid (aPL) antibodies are antibodies specific for anionic phospholipids. They are immunoglobulins that attack phospholipids, phospholipid-binding proteins, or phospholipid-protein complexes and are detected in anticardiolipin and lupus anticoagulant assays. aPL antibodies are often associated with antiphospholipid syndrome (APS) which can be idiopathic or from secondary causes such as systemic lupus erythematosus (SLE), infection or drugs. They have also been shown to be associated with Pulmonary Hypertension. We conducted a review of the literature that included all articles on PubMed with keywords 'antiphospholipid antibody' and 'pulmonary hypertension' between January 1980 and July 2017 and identified 217 articles. A total of 47 articles were found to be relevant to the topic and included as references. We ascertained that aPL antibodies have been implicated in the development of both idiopathic pulmonary arterial hypertension (PAH) and PAH associated with connective tissue disease (CTD). aPL antibodies were also noted to be associated with left-sided valvular heart disease that can lead to pulmonary venous hypertension (PVH). Patients with anitiphospholipid antibody syndrome (Diagnostic criteria incudes +aPL antibodies) were noted to have a high risk of developing chronic thromboembolic pulmonary hypertension (CTEPH). A recent study also found a positive association of aPL antibodies with ILD and PH in patients with systemic sclerosis. While association between autoimmune thyroid disease and PH (Group V PH), and autoimmune thyroid disease and aPL antibodies is established, no studies linked these three phenomena together. Thus, aPL antibodies had an association with all WHO groups of Pulmonary hypertension (PH). In this review article, we study the association and discuss the need for screening for PH in patients with positive aPL antibodies.