ORCID Profile
0000-0003-1461-3986
Current Organisations
KU Leuven
,
Universitaire Ziekenhuizen Leuven
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Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 25-05-2021
DOI: 10.1161/CIRCULATIONAHA.120.052899
Abstract: Exertional intolerance is a limiting and often crippling symptom in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Traditionally the pathogenesis has been attributed to central factors, including ventilation erfusion mismatch, increased pulmonary vascular resistance, and right heart dysfunction and uncoupling. Pulmonary endarterectomy and balloon pulmonary angioplasty provide substantial improvement of functional status and hemodynamics. However, despite normalization of pulmonary hemodynamics, exercise capacity often does not return to age-predicted levels. By systematically evaluating the oxygen pathway, we aimed to elucidate the causes of functional limitations in patients with CTEPH before and after pulmonary vascular intervention. Using exercise cardiac magnetic resonance imaging with simultaneous invasive hemodynamic monitoring, we sought to quantify the steps of the O 2 transport cascade from the mouth to the mitochondria in patients with CTEPH (n=20) as compared with healthy participants (n=10). Furthermore, we evaluated the effect of pulmonary vascular intervention (pulmonary endarterectomy or balloon angioplasty) on the in idual components of the cascade (n=10). Peak V o 2 (oxygen uptake) was significantly reduced in patients with CTEPH relative to controls (56±17 versus 112±20% of predicted P .0001). The difference was attributable to impairments in multiple steps of the O 2 cascade, including O 2 delivery (product of cardiac output and arterial O 2 content), skeletal muscle diffusion capacity, and pulmonary diffusion. The total O 2 extracted in the periphery (ie, ΔAV o 2 [arteriovenous O 2 content difference]) was not different. After pulmonary vascular intervention, peak V o 2 increased significantly (from 12.5±4.0 to 17.8±7.5 mL/[kg·min] P =0.036) but remained below age-predicted levels (70±11%). The O 2 delivery was improved owing to an increase in peak cardiac output and lung diffusion capacity. However, peak exercise ΔAV o 2 was unchanged, as was skeletal muscle diffusion capacity. We demonstrated that patients with CTEPH have significant impairment of all steps in the O 2 use cascade, resulting in markedly impaired exercise capacity. Pulmonary vascular intervention increased peak V o 2 by partly correcting O 2 delivery but had no effect on abnormalities in peripheral O 2 extraction. This suggests that current interventions only partially address patients’ limitations and that additional therapies may improve functional capacity.
Publisher: SAGE Publications
Date: 10-09-2020
Abstract: To assess the in vivo hemodynamic effects on the pressure overloaded right ventricle of RAS-Q ® technology, the world’s first gas exchanger with a fully integrated compliance. In six acute in vivo trials RAS-Q was implanted in sheep between the pulmonary artery and left atrium. Right ventricular pressure overload was induced by pulmonary artery banding. Pressures and flows were recorded in baseline, moderate and severe pulmonary hypertension conditions. In one trial, RAS-Q was benchmarked against the pediatric Quadrox-i ® . With 1.00 and 1.17 L/min, RAS-Q delivered 31% and 39% of the total cardiac output in moderate and severe pulmonary hypertension, respectively. Pulmonary artery pressures and mean pulmonary artery pressure/mean arterial blood pressure ratio successfully decreased, implying a successful right ventricular unloading. Cardiac output was restored to normal levels in both pulmonary hypertension conditions. With both devices in parallel, RAS-Q provided three times higher flow rates and a 10 times higher pressure relief, compared to the pediatric Quadrox-i. A gas exchanger with a fully integrated compliance better unloads the right ventricle compared to a non-compliant gas exchanger and it can restore cardiac output to normal levels in cases of severe pulmonary hypertension.
Location: India
No related grants have been discovered for Tom Verbelen.