Left Atrial Reservoir Longitudinal Strain is a Resting Marker of Exercise Capacity in Chronic Heart Failure: A Cross-sectional Study

Abstract

Background: Left atrial (LA) function is an important parameter for assessing left ventricular performance. This study investigated the relationship between LA function as determined by strain analysis and exercise capacity in patients with chronic heart failure (CHF). Methods: A total of 51 patients with CHF were prospectively recruited from the Baduanjin-eight-silken-movement With Self-efficacy Building for Patients With Chronic Heart Failure study. Resting echocardiographic parameters including the ratio of transmitral E velocity to tissue Doppler mitral annulus e′ velocity (E/e′), minimum left atrial volume index (LAVI min ), maximum left atrial volume index (LAVI max ), and left atrial empty fraction (LAEF) as well as global phasic longitudinal strain (reservoir strain [LALSr], conduit strain [LALScd], and contractile strain [LALSct]) were measured and compared with maximum oxygen uptake (VO 2max ) in terms of performance in predicting reduced exercise capacity. Results: Mean age of study patients was 60.18 ± 10.41 years, mean left ventricular ejection fraction was 32.8 ± 14.2%, and mean VO 2max was 17.02 ± 4.64 mL/kg/min. Eleven (21.57%) patients were women, and 32 (62.75%) had coranary heart disease. Univariate linear regression analysis identified age and N-terminal prohormone of brain natriuretic peptide level as independent clinical parameters associated with VO 2max (both P<0.05); independent resting echocardiographic parameters included LALSRr (P<0.001); average late diastolic velocity of septal and lateral wall annulus, LAVI max , LAVI min , LALSRr, LALSRct, and LAEF (all P<0.01); and E and E/e′ (both P<0.05). The multivariate linear regression analysis revealed 4 independent clinical predictors of VO 2max including (β = 0.351; P = 0.007), age (β = -0.271; P = 0.027), body mass index (β = -0.260; P = 0.032) and N-terminal prohormone of brain natriuretic peptide (β = -0.257; P = 0.041). Conclusions: LALSr is a marker of decreased LA compliance and an independent correlate of VO 2max with high diagnostic value in patients with CHF. Thus, LALSr can be used for risk stratification of CHF patients with reduced exercise capacity and poor cardiovascular outcome. Trial registration: NCT03180320 (ClinicalTrials.gov). Registered 8 June 2017, https://clinicaltrials.gov/ct2/show/NCT03180320?term=Baduanjin-eight-silken-movement&draw=2&rank=1.