Endothelial Function and Vascular Properties in Severe Aortic Stenosis Before and After Aortic Valve Replacement Surgery.

INTRODUCTION: The degenerative process that results in aortic valve stenosis (AS) has pathophysiological features similar to the atherosclerotic process. We therefore hypothesized that, as in atherosclerosis, endothelial and vascular dysfunction could be a pathophysiologic feature of AS. AIM: To evaluate endothelial function before and after aortic valve replacement (AVR) surgery in patients with severe AS. To correlate endothelial function with severity of AS and clinical profile. METHODS: Two noninvasive methods were used to evaluate endothelial function (Reactive Hyperemia Index (RHI) measure with EndoPATTM2000 system) and vascular properties (carotid-femoral Pulse Wave Velocity (PWV) measured by Complior® Analyse) in 13 patients with severe AS undergoing AVR. Sample was collected by convenience in a single-center between February and July of 2017. Pre- -operative, surgical and post-operative data were collected through clinical files and informatics databases. PWV, RHI, Augmentation Index (AI) were assessed at the day of surgery and 2.4±1.2 months post-operatively. Mean transvalvular gradients (MTG), aortic valve area (AVA) and left ventricular function were evaluated by transthoracic echocardiography at 3.4±1.6 months of follow-up. Wilcoxon or paired t-tests were used to compare pre- and post-operative values of continuous variables. Spearman correlations (rho) were done to find associations between endothelial/ vascular function parameters and clinical data. RESULTS: In our sample, mean age was 70±8 years and 69% were females. Arterial hypertension was present in 11 (85%) patients, diabetes in 3 (23%) and pre-operative NYHA functional class ≥III in 4 (31%). No patient was currently smoker and only 2 had previous history of smoking. No significant changes were observed between pre- and post-operative endothelial/vascular function values. PWV (m/s), AI (%) and RHI before and after AVR surgery were: 10.5 (6.1 to 16) vs. 9.4 (4.7 to 21.6), p=0.701; 33% [-24 to 54] vs. 23% [0 to 47], p=0.116 and 1.83 (1.08 to 3.13) vs. 1.71 (1.06 to 3.12), p=0.638, respectively. We found a significant inverse correlation between pre- operative AVA and AI (rho= -0.652, p=0.016) and a positive correlation between age and post-operative PWV (rho= 0.639, p=0.019). Pre- and post-operative MTG and AVA were 54±5 mmHg and 0.7± 0.1 cm2 vs.12±4 mmHg and 2.0±0.5 cm2, respectively (p<0.001). CONCLUSION: Considering small sample size, no differences were found in indices of endothelial/vascular function before and after AVR surgery due to AS. However, it seems that endothelial dysfunction is associated with severity of AS assessed by AVA.