Incremental Prognostic Utility of Left Ventricular Global Longitudinal Strain in Asymptomatic Patients With Significant Chronic Aortic Regurgitation and Preserved Left Ventricular Ejection Fraction

Abstract

ObjectivesThis study sought to examine the prognostic utility of left ventricular (LV) global longitudinal strain (GLS) in asymptomatic patients with ≥III+ aortic regurgitation (AR), an indexed LV end-systolic dimension of <2.5 cm/m2, and preserved left ventricular ejection fraction (LVEF). BackgroundManagement of asymptomatic patients with severe chronic AR and preserved LVEF is challenging and is typically based on LV dimensions. MethodsWe studied 1,063 such patients (age 53 ± 16 years; 77% men) seen between 2003 and 2010 (excluding those with symptoms, obstructive coronary artery disease, acute AR/dissection, aortic/mitral stenosis, more than moderate mitral regurgitation, and previous cardiac surgery). Society of Thoracic Surgeons (STS) score was calculated. The primary endpoint was mortality. Average resting LV-GLS was measured offline on 2-, 3-, and 4-chamber views using Velocity Vector Imaging (Siemens, Malvern, Pennsylvania). ResultsMean STS score, LVEF, LV-GLS, and right ventricular systolic pressure were 4.4 ± 5.0%, 57.0 ± 4.0%, −19.5 ± 0.2%, and 31.0 ± 9.0 mm Hg, respectively. In total, 671 patients (63%) underwent aortic valve surgery at a median of 42 days after the initial evaluation. At 6.8 ± 3.0 years, 146 patients (14%) had died. On multivariable Cox survival analysis, LV-GLS (hazard ratio [HR]: 1.11), STS score (HR: 1.51), indexed LV end-systolic dimension (HR: 0.50), right ventricular systolic pressure (HR: 1.33), and aortic valve surgery (HR: 0.35) were associated with longer term mortality (all p < 0.001). Sequential addition of LV-GLS and aortic valve surgery improved the C-statistic for longer term mortality for the clinical model (STS score + right ventricular systolic pressure + indexed LV end-systolic dimension) from 0.61 (95% confidence interval [CI]: 0.51 to 0.72) to 0.67 (95% CI: 0.54 to 0.87) and to 0.77 (95% CI: 0.63 to 0.90), respectively (p < 0.001 for both). A significantly higher proportion (log-rank p = 0.01) of patients with LV-GLS worse than median (−19.5%) died versus those with an LV-GLS better than median (86 of 513 [17%] vs. 60 of 550 [11%]). The risk of death at 5 years significantly increased with an LV-GLS of worse than −19%. ConclusionsIn asymptomatic patients with ≥III+ chronic AR and preserved LVEF, worsening LV-GLS was associated with longer term mortality, providing incremental prognostic value and improved reclassification.