Prognostic value of contractile reserve evaluated by global longitudinal strain in patients with asymptomatic severe aortic stenosis
Authors: Rosina Arbucci RA , Maria Graciela Rousse MGR , Diego Maximiliano Lowenstein DML , Ariel Karim Saad AKS , Cristian Caniggia CC , Miguel Amor MA , Natalio Gastaldello NG , Esteban L Clos ELD , Liliana Martinez LM , Pablo Merlo PM , Gustavo Zambrana GZ , Marcela Galello MG , Vicente Mora VM , Jorge Alfredo Lowenstein JAL 
Published: February 2021

Abstract

Funding Acknowledgements
Type of funding sources: Private company. Main funding source(s): Investigaciones Médicas. Cardiodiagnóstico. Buenos Aires
Introduction. Left ventricle Global Longitudinal Strain(GLS) at rest has shown prognostic value in patients(pts) with severe aortic stenosis(SAS). Contractile reserve(CR) during exercise stress echo(ESE) estimated by GLS(CR-GLS) could better stratify the asymptomatic patients who could benefit from early intervention.
Objective. To establish the long-term prognostic value of CR-GLS in pts with asymptomatic SAS during ESE. Secondly, to compare if the CR evaluated by ejection fraction(CR-EF) presented similar results to those of CR-GLS.
Methodology. In a single center, prospective study carried out between May 2013 to Oct 2019, we enrolled 101 pts(69 ± 12 years,54 men) with asymptomatic SAS(aortic valve area &lt; 0,6cm2/m2) and preserved EF(&gt;55%). GLS value was considered as the average of the 16 segments, obtained from the apical views of 3, 4 and 2 chambers at rest and peak ESE. CR was considered present with stress-rest increase of &gt;5points with EF and &gt;2 absolute points by GLS. The pts were divided into 2 groups(G): G1:Pts with presence of CR-GLS and G2:Pts with absence of CR-GLS. Major cardiovascular event was considered to be: need for valve replacement due to the presence of symptoms, death, acute myocardial infarction and stroke. All patients were followed-up.
Results. Of the 101 pts analyzed, 56pts(55.4%) were included in G1(CR-GLS) and 45pts(44.6%) in G2(no CR-GLS). The G2 patients were older(G2 72.2 ± 8.5 vs G1 66.5 ± 14.1) with lower METS(G1 5.6 ± 2 vs G2 4.2 ± 1.1,p 0.004), a higher percentage of flat blood pressure response(G1 19.6% vs. G2 37.8%,p 0.036), lower peak EF(G1 71.5%±5.8 vs G2 66.8 ± 7.9,p0.001),peak GLS(G1 -22.2%±2.8 vs G2 -18.45%±2.4 p 0.001) and lower ΔGLSstress-rest(G1 GLS 3.07 ± 0.85 vs G2 0.08 ± 1.9 p 0.003). The same behaviour with the EF response(G1 7.32 ± 2.9 vs G2 4.7 ± 5.3,p 0.024). The average follow-up was 46.6 ± 3.4 months, and events occurred in 45 patients: 12 all-cause deaths(9 cardiac), 31 valve replacement, 1 myocardial infarctions, 1 strokes. G2 pts had more events compared to G1 pts (G2 = 26 events 57.8% vs G1 = 19 events 42.2%,p &lt; 0.01)(figure 1). The CR-EF did not separate patients with and without events. At Cox analysis, CR-GLS was the only predictor variable of major events(HR:1.97, 95% CI 1.09-3.58)p &lt; 0.025).

Conclusions
In patients with asymptomatic SAS, the absence of CR-GLS during ESE identifies a group of patients with a worse prognosis and the need for aotic valve intervention. CR-GLS proved to be superior tan CR-EF.
Baselin characteristic between groups
Abstract Figure. Left ventricle RC-GLS and survival