Impact of surgical aortic valve replacement on global and regional longitudinal strain across four flow gradient patterns of severe aortic stenosis.

Abstract

To evaluate the impact of surgical aortic valve replacement (SAVR) on global (GLS) and regional longitudinal strain (RLS) across four flow-gradient patterns of severe aortic stenosis (AS) 3 months after surgery.A total of 103 patients with severe AS (aortic valve area < 1.0 cm2) were examined by speckle tracking echocardiography the day before SAVR and at 3-months follow-up. Patients were stratified into four flow-gradient patterns by stroke volume index (>35 mL/m2 vs. ≤35 mL/m2) and mean transaortic gradients (>40 mmhg vs. ≤40 mmhg): normal-flow, high gradient (NF/HG); low-flow, high gradient (LF/HG); normal-flow, low gradient (NF/LG); low-flow, low gradient (LF/LG). Strain analysis comprised GLS and RLS at a basal (BLS), mid-ventricular (MLS) and apical level (ALS).Patients with high gradients improved GLS (NF/HG: 16.1 ± 3.5 % vs. 17.3 ± 3.4 %, p = 0.03 and LF/HG: 15.4 ± 3.6 % vs. 16.9 ± 3.1 %, p = 0.03), BLS (NF/HG: 12.7 ± 3.1 % vs. 14.2 ± 3.1 %, p = 0.003 and LF/HG: 11.4 ± 3.2 % vs. 13.8 ± 2.7 %, p = 0.005) and MLS (NF/HG: 15.4 ± 3.3 % vs. 16.5 ± 3.3 %, p = 0.04 and LF/HG: 14.5 ± 3.1 % vs. 16.2 ± 2.7 %, p = 0.01) whereas patients with low gradients showed no improvements three months after SAVR. ALS did not change significantly in any group. Patients with high gradients demonstrated a reduction in left ventricular (LV) mass index (p < 0.001) and N-terminal pro-Brain Natriuretic Peptide levels (p < 0.001) following SAVR in contrast to patients with low gradients.Patients with high gradient severe AS improve GLS and RLS three months after SAVR with concomitant reduction of LV mass and neurohormonal activation whereas patients with low gradients do not improve longitudinal strain, LV mass or neurohormonal activation.