Left atrial strain is associated with cardiovascular outcomes in children with congenitally corrected transposition of the great arteries

Abstract

Abstract Background The assessment of the systemic right ventricular (sRV) function in congenitally corrected transposition of the great arteries (ccTGA) by echocardiography is restricted by its complex geometry. Purpose To determine the utility of left atrial strain (LAS) and sRV longitudinal strain (sRV-LS) in the prediction of outcomes in children with ccTGA. Methods This nested case-control study included all patients <21 years old with unrepaired ccTGA at our tertiary pediatric institution who had an echocardiogram prior to cardiovascular outcomes (milrinone-dependent heart failure, ventricular assistant device, heart transplant or death). LAS (both R wave and P wave references) and sRV-LS were measured using TomTec AutoStrain. To account for potential confounders, cases and controls were matched (1 cases vs 3 controls) by age ± 1 year and tricuspid regurgitation (TR) severity (none/mild vs. moderate/severe). Univariable conditional logistic regression was employed to assess the association between LAS and sRV-LS with outcomes among matched patients. Results Of 101 patients (64% male) with echocardiogram performed at 1.78 years old (IQR 0.02, 9.80), 14 (14%) developed an outcome. Baseline characteristics, LAS, and sRV-LS are depicted in Table 1. LAS and sRV-LS were not discriminative between age-matched cases and controls. In the matched cases and controls for TR severity, each unit-increase in LAS conduit phase (LAScd R and LAScd P) was associated with 18% and 22% higher odds of outcomes respectively, although these did not achieve statistical significance (LAScd R OR 1.2, 95% CI 1.0-1.4, p=0.09; LAScd P OR 1.2, 95% CI 1.0-1.5, p=0.08, Table 2). Conclusions After controlling for TR severity as a potential confounding factor, the conduit phase of LAS by both R wave and P wave references may have clinical implications as predictors of cardiovascular outcomes in patients with ccTGA. Larger and more well-powered studies are needed to further evaluate this association and studying longitudinal changes in LAS may provide insight in the development of outcomes in this population.