Changes in global longitudinal strain after TAVI: additional prognostic value over cardiac damage staging in severe aortic stenosis
Authors: Myagmardorj R , Nabeta T , Galloo X , Meucci C M , Butcher S , Van Der Kley F , Bax J J , Ajmone Marsan N 
Published: November 2023

Abstract

Background
Aortic stenosis (AS) is the most prevalent valvular heart disease in the aging population and has significant impact on cardiac function. In these patients, previous studies proposed an extra-valvular cardiac damage staging, which demonstrated a strong prognostic value. Left ventricular global longitudinal strain (LVGLS) has also been shown to be a better measure of LV performance in AS patients, and when impaired to be a robust predictor of adverse outcomes. Transcatheter aortic valve implantation (TAVI) can improve both cardiac damage stage and LVGLS significantly, but little is known about their prognostic value when measured after TAVI.

Purpose
To evaluate the changes and prognostic value in the extra-valvular cardiac damage staging and in LVGLS from baseline to 6 months follow-up after TAVI.

Methods
Patients with severe AS undergoing TAVI were analyzed retrospectively. Echocardiography was performed and measured before and 6 month after TAVI. Patients were hierarchically classified in a cardiac damage stage (worst stage) if at least one of the proposed criteria was met. The staging included: stage 0 = no signs of cardiac damage; stage 1 = LV ejection fraction &lt; 50% and/or E/e´&gt; 14 and/or LV mass index &gt; 115 g/m2 (male) or &gt; 95 g/m2 (female); stage 2 = Significant mitral regurgitation and/or Left atrial volume index &gt; 34 mL/m2; stage 3 = Pulmonary artery systolic pressure ≥ 60 mmHg and/or Significant tricuspid regurgitation; stage 4 = Tricuspid annular planar systolic pressure &lt; 16 mm. GLS was measured at baseline and follow-up. The primary endpoint was all-cause mortality.

Results
In total, 620 patients were included for paired analysis. At baseline, 4% of patients were classified as stage 0, 11% as stage 1, 30% as stage 2, 31% as stage 3, and 24% as stage 4, distinctly. At 6 months follow-up, 3% of the patients were classified as stage 0, 19% as stage 1, 49% as stage 2, 20% as stage 3, and 9% as stage 4. At 6 months follow-up, LVGLS significantly improved in the overall population (13.6% versus 16.3%, p&lt;0.0001), and the improvement in LVGLS was similar among each baseline cardiac damage stage (Figure 1). Follow-up LVGLS values were divided in quantiles and implemented in the definition of follow-up cardiac damage stages, leading to a reclassification of 308 patients. Kaplan-Meier curve showed that survival rates in patients stratified by the new cardiac damage stage, including LVGLS, was significantly different (Figure 2). Multivariate Cox regression models showed that follow-up LVGLS and the re-classified cardiac damage stage (including LVGLS) had significant incremental prognostic value as compared to baseline variables. (Figure 2).

Conclusions
LVGLS improves at follow-up after TAVI independently of the cardiac damage stage at baseline; assessment of LV GLS and cardiac damage stage (also when combined for patient classification) is of additional prognostic value as compared to baseline assessment alone.Changes in LV GLS by each stageKM curve and Multivariate Cox regression