Abstract 17200: Valvulo Arterial Impedance and Systemic Arterial Compliance Are Associated With Changes in Flow Category in Severe Aortic Stenosis With Preserved Left Ventricular Ejection Fraction on Medical Therapy
Introduction: Paradoxical low flow (LF) severe aortic stenosis (AS) despite preserved left ventricular ejection fraction (LVEF) has recently been described. We aim to investigate if patients in the NF group may become LF and vice versa and determine their associated predictors.
Methods: We studied 179 consecutive subjects with aortic valve area indexed to body surface area (AVAI) 180 days apart. There were 67 pts (37%) with LF (stroke volume index (SVI) <35mL/m2) and 112 (63%) with NF. Within each group we identified subjects with changes in flow category and compared their baseline parameters.
Results: Mean paired echo interval is 1020±870 days. Majority remain within their flow groups with 33% progresses from NF to LF (Gp B) and 25% from LF to NF (Gp D). SVI decreases from 42±7 to 29±3 and increases from 29±4 to 41±5 mL/m2 in Gps B and D respectively. AVAI decreases from 0.48±0.09 to 0.42±0.11 and 0.50± .08 to 0.40±0.12 cm2/m2 in Gp A and B respectively but LVEF decreases from 63±11 to 52±16% in Gp B only (P<0.001). Zva increases from 4.04±0.69 to 5.71±0.82 mmHg/ml/m2 (P<0.001) and SAC decreases from 0.74±0.26 to 0.54±0.16 ml/mmHg (P<0.001)in Gp B. Zva predicts switch from NF to LF (P=0.004,Table). In contrast, Zva decreases from 6.13±1.59 to 4.43±0.86 mmHg/ml/m2 (P<0.001) and SAC increases from 0.52±0.21 to 0.71±0.22 ml/mmHg (P=0.015) in Gp D. Higher mean transaortic gradient predicts change from LF to NF.
Conclusion: A significant number of LF severe AS despite preserved LVEF and NF AS patients switch groups. This appears to be associated with respective changes in Zva and SAC.
- © 2013 by American Heart Association, Inc.