Abstract 15718: Valvulo-Arterial Impedance in ESKD Patients With Aortic Stenosis: Echocardiographic Correlates and Outcomes

Abstract

Introduction: Higher values of valvulo-arterial impedance (Zva), a marker of global hemodynamic load, are associated with worse outcomes in patients with aortic stenosis (AS). No studies have evaluated the impact of Zva on outcomes in end stage kidney disease (ESKD) patients with AS. Objectives We aim to evaluate clinical outcomes associated with Zva and echocardiographic correlates of Zva in patients with AS and ESKD. Methods: Consecutive ESKD patients on dialysis with AS on echocardiography from a single center between January 2000 and March 2021. AS severity was defined using AHA guideline recommendations. Zva [units: mmHg/ml/m 2 ] was calculated as (systolic arterial pressure + aortic valve mean gradient) divided by indexed stroke volume. The association of high Zva with the combined primary outcome of aortic valve replacement (AVR) or mortality was assessed using Cox proportional hazard analysis. Results: The cohort included 94 patients with co-prevalent ESKD and AS; mean age 66 years, 71% male; 43% Black, 24% severe AS. Patients with Zva>4 mmHg/ml/m2 (median value; Table ) associated with lower indexed aortic valve area (0.52 vs. 0.71 cm 2 /m 2 , p<0.001), lower stroke volume (66 vs. 84 ml; p<0.001), lower cardiac output (5.3 vs. 6.1 L/min; p=0.005); Figure . Zva did not associate with the combined incidence of AVR or mortality (p=0.2). Conclusion: In ESKD patients with AS, high Zva was associated with smaller AVA and measures of low flow state; but not with the primary outcome of AVR or mortality. These findings should be validated in a larger cohort. Differences in prognostic information from Zva and flow states in the context of AS between ESKD vs non-ESKD patients deserve further study.