Automated Global Longitudinal Strain Exhibits a Robust Association with Death in Asymptomatic Chronic Aortic Regurgitation

Background: Whether automated left ventricular global longitudinal strain (LVGLS) is associated with outcomes in patients with asymptomatic aortic regurgitation (AR) is unknown. The aim of this study was to explore the impact of automated LVGLS on survival and compare it with conventional left ventricular (LV) parameters in patients with chronic asymptomatic AR. Methods: LVGLS (presented as an absolute value) was measured using fully automated two-dimensional strain software in consecutive patients with isolated chronic moderate to severe or greater AR between 2004 and 2020; the incremental value of LVGLS was assessed. Limited correction of endocardial border tracking was performed if needed. Results: Of 550 asymptomatic patients (mean age, 60 ± 17 years; 86% men), average LVGLS was 17 ± 3% (first and second tertiles, 15.8% and 18.5%). In 16% of cases, tracking border was partially corrected; average time for analysis was 25 ± 5 sec. At a median of 4.8 years (interquartile range, 1.5-9.9 years), 87 patients had died (19 died after aortic valve surgery). Separate multivariable models adjusted for age, sex, Charlson index, AR severity, and time-dependent aortic valve surgery demonstrated that LV ejection fraction (hazard ratio [HR] per 10%, 0.9), LV end-systolic volume index (LVESVi; HR per 5 mL/m², 1.08) and LVGLS (HR per unit, 0.87) were independently associated with death (P ≤.018 for all); however, LVGLS remained statistically significant (HR: 0.86-0.9; P ≤.007) when compared head-to-head with LV ejection fraction, LVESVi, and LV end-systolic dimension index. The association of LVGLS and mortality was consistent across all subgroups (P for interaction ≥.08 for all). Spline curves showed that continuous risk for death rose at LVGLS < 15%. Those with LVGLS < 15% had a 2.6-fold risk for death (95% CI, 1.54-4.23) while those with LVGLS < 15% plus LVESVi ≥ 45 mL/m² had 3.96-fold risk (95% CI, 1.94-8.03). Conclusions: In this large cohort of asymptomatic patients with moderate to severe or greater AR, automated LVGLS was feasible, efficient, and independently associated with death in head-to-head comparisons with conventional LV ejection fraction, LV end-systolic dimension index, and LVESVi. An automated LVGLS threshold of <15% alone or combined with LVESVi ≥ 45 mL/m² was significantly associated with increased mortality risk and may be considered in early surgery decision-making.