The effect of surgical versus transcatheter aortic valve replacement on endothelial function. An observational study

Background: The effects of surgical aortic valve replacement versus transcatheter aortic valve replacement on endothelial function are unknown. We investigated the effects of surgical and transcatheter aortic valve replacement on early and 90-day endothelial function measured by brachial flow mediated dilation and apoptotic rate in the human umbilical vein endothelial cells in patients with significant aortic stenosis, intermediate risk of surgery, and no coronary artery disease. Methods: We conducted a prospective observational case control single-blind study at a single tertiary center. Endothelial function was measured at baseline, early post-procedure (4 days), and follow-up (90 days). A blood pressure cuff was used to elicit reactive hyperemia for measuring brachial wall shear stress and flow mediated dilation. The apoptosis rate was observed in the human umbilical vein endothelial cells after 48-h incubation with 20% serum from patients. The rate of apoptosis was assessed by determining the number of annexin V and propidium iodide positive cells by flow cytometry. Results: Early post-procedure flow dilation was significant lower in the surgical group (p < 0.003). At follow-up, both groups showed incremental increases in flow mediated dilation. Surgical group apoptotic rate did not significantly change, while transcatheter apoptotic rate steadily decreased, suggesting a trend toward improved endothelial function. Conclusions: The data suggest that conventional surgical aortic valve replacement may be associated with an early and transient decrease in endothelial function, likely due to the use of cardio-pulmonary bypass.