Distribution and Prognostic Significance of Left Ventricular Global Longitudinal Strain in Asymptomatic Significant Aortic Stenosis: An Individual Participant Data Meta-Analysis

Abstract

Objectives: In this individual participant data meta-analysis on left ventricular global longitudinal strain (LVGLS), our objective was to: 1) describe its distribution; 2) identify the most predictive cutoff values; and 3) assess its impact on mortality in asymptomatic patients with significant aortic stenosis (AS) and preserved left ventricular ejection fraction (LVEF).

Background: The evidence supporting the prognostic role of LVGLS in asymptomatic patients with AS has been obtained from several relatively small studies.

Methods: A literature search was performed for studies published between 2005 and 2017 without language restriction according to the following criteria: "aortic stenosis" AND "longitudinal strain." The corresponding authors of selected studies were contacted and invited to share their data that we computerized in a specific database. The primary endpoint was all-cause mortality.

Results: Among the 10 studies included, 1,067 asymptomatic patients with significant AS and LVEF >50% were analyzed. The median of LVGLS was 16.2% (from 5.6% to 30.1%). There were 91 deaths reported during follow-up with median of 1.8 (0.9 to 2.8) years, resulting in a pooled crude mortality rate of 8.5%. The LVGLS performed well in the prediction of death (area under the curve: 0.68). The best cutoff value identified was LVGLS of 14.7% (sensitivity, 60%; specificity, 70%). Using random effects model, the risk of death for patients with LVGLS <14.7% is multiplied by >2.5 (hazard ratio: 2.62; 95% confidence interval: 1.66 to 4.13; p < 0.0001), without significant heterogeneity between studies (I² = 18.3%; p = 0.275). The relationship between LVGLS and mortality remained significant in patients with LVEF ≥60% (p = 0.001).

Conclusions: This individual participant data meta-analysis demonstrates that in asymptomatic patients with significant AS and normal LVEF, impaired LVGLS is associated with reduced survival. These data emphasize the potential usefulness of LVGLS for risk stratification and management of these patients.

Keywords: aortic valve stenosis; left ventricular global longitudinal strain; meta-analysis; mortality.