Hepatocyte Growth Factor Receptor c-Met Instructs T Cell Cardiotropism and Promotes T Cell Migration to the Heart via Autocrine Chemokine Release

© 2015 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)This study was funded by the British Heart Foundation (RG/09/002/2642 to F.M.M.-B.) and the Medical Research Council of the UK (G0901084 to F.M.M.-B.). ImageStream X was funded by the Wellcome Trust (101604/Z/13/Z). This work forms part of the research themes contributing to the translational research portfolio of Barts and the London Cardiovascular Biomedical Research Unit, which is supported and funded by the National Institute of Health Research

Influence of cardiopulmonary bypass on the interaction of recombinant factor VIIa with activated platelets

Recombinant factor VIIa (rFVIIa) interacts preferentially with coated platelets characterized by a high exposure of phosphatidyl serine (PS), FV, FVIII, FIX, and FX binding, and fibrinogen. Cardiopulmonary bypass (CPB) is known to impair platelet function. In this study, the influence of CPB on formation of coated platelets and the interaction of rFVIIa with the platelets were studied. Blood was either exposed to a closed CPB circuit or obtained from patients undergoing CPB-assisted cardiac surgery, and platelets were analyzed by flow cytometry with and without dual agonist stimulation with thrombin and a GPVI collagen receptor agonist known to induce coated platelet formation. Platelets circulated within a closed CPB circuit did not spontaneously form coated platelets. Dual agonists stimulation caused formation of coated platelets at a reduced level compared to pre-CPB level (51 ± 21% vs. 80 ± 17% before CPB, p < .001). The rFVIIa interaction with the coated platelets was not impaired after CPB. Platelets isolated from patients undergoing CPB-assisted cardiac surgery also formed coated platelets only after dual agonist stimulation but to the same level as before surgery (76 ± 8% vs. 83 ± 14% before surgery, p = .17, n = 10). rFVIIa interaction with the coated platelets was not impaired after surgery. No spontaneous rFVIIa-binding platelets were found. The data indicate that CPB exposure in vivo does not compromise the platelet-dependent effects of rFVIIa either by spontaneous formation of coated platelets, thereby limiting the risk of systemic coagulation, or by impairing rFVIIa interaction with the agonist-induced coated platelets, thereby retaining the hemostatic potential of rFVIIa after CPB

Durability of Transcatheter and Surgical Bioprosthetic Aortic Valves in Patients at Lower Surgical Risk

Background: Transcatheter aortic valve replacement (TAVR) is an alternative to surgical aortic valve replacement (SAVR) in patients with severe aortic stenosis and intermediate or high surgical risk. Objectives: The aim of this study was to compare the durability of transcatheter and surgical bioprosthetic aortic valves using standardized criteria. Methods: In the NOTION (Nordic Aortic Valve Intervention) trial, all-comer patients with severe aortic stenosis and lower surgical risk for mortality were randomized 1:1 to TAVR (n = 139) or SAVR (n = 135). Moderate/severe structural valve deterioration (SVD) was defined as a mean gradient ≥20 mm Hg, an increase in mean gradient ≥10 mm Hg from 3 months post-procedure, or more than mild intraprosthetic aortic regurgitation (AR) either new or worsening from 3 months post-procedure. Nonstructural valve deterioration (NSVD) was defined as moderate/severe patient-prosthesis mismatch at 3 months or moderate/severe paravalvular leakage. Bioprosthetic valve failure (BVF) was defined as: valve-related death, aortic valve reintervention, or severe hemodynamic SVD. Results: At 6 years, the rates of all-cause mortality were similar for TAVR (42.5%) and SAVR (37.7%) patients (p = 0.58). The rate of SVD was higher for SAVR than TAVR (24.0% vs. 4.8%; p &lt; 0.001), whereas there were no differences in NSVD (57.8% vs. 54.0%; p = 0.52) or endocarditis (5.9% vs. 5.8%; p = 0.95). BVF rates were similar after SAVR and TAVR through 6 years (6.7% vs. 7.5%; p = 0.89). Conclusions: In the NOTION trial through 6 years, SVD was significantly greater for SAVR than TAVR, whereas BVF was low and similar for both groups. Longer-term follow-up of randomized clinical trials will be necessary to confirm these findings. (Nordic Aortic Valve Intervention Trial; NCT01057173