Background: Transcatheter aortic valve replacement (TAVR) exposes the systemic vasculature to increased mechanical forces. Endothelial adaptation to mechanical stimuli is associated with angiogenic activation through various growth factors. We studied the potential angiogenic shift evoked by TAVR.
Methods: From a cohort of 69 consecutive patients undergoing TAVR, we excluded patients with conditions known to affect angiogenic factors, and serum vascular endothelial growth factor (VEGF) and angiopoietin (Ang)-1 and Ang-2 were assessed by ELISA. We assessed in vitro the properties of endothelial cells after exposure to serum collected from patients undergoing TAVR using adhesion, migration, and Matrigel angiogenesis assays. The correlation between changes in angiogenic factors and cardiac functions was evaluated on 30- day echocardiograms.
Results: The study population consisted of 46 patients (82 ± 5 years). Two days after TAVR the post/pre TAVR ratio of VEGF, Ang-1, and Ang-2 was 5.38 ± 4 (P < 0.001), 1.05 ± 0.49 (P = 0.27), and 4.65 ± 2.01 (P < 0.001), respectively. The increase in VEGF and Ang-2 showed a significant correlation (r = 0.609; P < 0.001), but no correlation was found with hemolysis or tissue injury markers. Patients with relatively low levels of VEGF or an Ang-2 rise had more severe aortic stenosis and coronary disease at baseline. Exposure of endothelial cells to post-TAVR serum induced adhesion, migration, and tube formation compared with pre-TAVR serum. An increase in VEGF levels correlated with improvement in pulmonary systolic pressure and a right ventricular fractional area change at 30 days, (r = 0.54 and r = 0.48, respectively; P < 0.01).
Conclusions: Sustained elevation of VEGF and Ang-2 levels occur after TAVR, reflecting a systemic angiogenic shift. A rise in VEGF levels is associated with a decrease in pulmonary blood pressure in patients undergoing TAVR.
Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.