Incremental Diagnostic Value of LA Strain With Leg Lifts in Heart Failure With Preserved Ejection Fraction

Abstract

The purposes of this study were to examine left atrial (LA) functional reserve in patients with heart failure (HF) with preserved ejection fraction (HFpEF) and to determine whether LA strain has an incremental diagnostic value over clinical and conventional echocardiographic parameters. Patients with HFpEF have multiple cardiovascular reserve abnormalities. Although the LA is dysfunctional in HFpEF, the diagnostic value of LA strain remains unknown. The LA at rest and during passive leg lifts was echocardiographically assessed in 40 patients with HFpEF and in 46 patients with hypertension without HF (HT controls). Global peak atrial longitudinal strain during ventricular systole (global LAS) and booster strain during atrial contraction (global LAB) were assessed using speckle tracking. Patients with HFpEF had an enlarged LA and reduced LA emptying fraction compared with HT controls at rest, while LA stroke volume (SV) was similar between the groups. During leg lifts, increases in LA reservoir and contractile function (i.e., global LAS and LAB) were blunted in HFpEF patients compared with HT controls, resulting in impaired LASV responses. Global LAS and LAB during leg lifts accurately differentiated HFpEF from HT controls (areas under the curve: 0.95 and 0.92, respectively). Resting global LAS had a significant incremental diagnostic value over clinical (age and sex) and conventional echocardiographic parameters (E/E' ratio, left ventricular mass index, and maximum LA volume index) (global chi-square: 49.6 vs. 30.8; p < 0.0001). The diagnostic value was further improved by adding global LAS during leg lifts (global chi-square: 72.2 vs. 49.6; p < 0.0001). An enlarged LA compensates for LA dysfunction and maintains LASV at rest in patients with HFpEF. However, depressed LA reserve affects LA performance during leg lifts. Evaluation of LA function, including LA strain using leg lifts, might provide incremental diagnostic value for HFpEF.