Clinical Utility of Left Atrial Strain in Children in the Acute Phase of Kawasaki Disease

Background: We aimed to evaluate the diagnostic utility of peak left atrial longitudinal strain ( PALS) during left ventricular ( LV) systole to differentiate children in the acute phase of Kawasaki disease ( aKD) from controls. We also aimed to compare the diagnostic utility of PALS with those of conventional echocardiographic indices of diastolic function. Methods: Retrospectively measured PALS, LV longitudinal peak systolic strain, and strain rate obtained via velocity vector imaging were compared in a derivation cohort comprising 95 aKD and 67 controls. The utility of PALS in differentiating aKD from controls was compared with those of E/E', E/A, and maximum left atrial volume index ( LAVImax). Derived cutoffs from receiver operating characteristic curves were validated in a separate validation cohort comprising 37 aKD and 19 controls. Results: In the derivation cohort, PALS was significantly decreased in aKD as compared with in controls. For differentiating aKD from controls, PALS outperformed E/E', E/A, and LAVImax. However, cutoffs of PALS (<40% and <39%, before and after adjusting for the presence of significant mitral regurgitation and LV systolic dysfunction, respectively), like those of E/E', E/A, and LAVImax, showed low sensitivity and poor discriminative ability for differentiating aKD from controls. In the validation cohort, for differentiating aKD from controls, both cutoffs of PALS showed low sensitivity, like those of E/E', E/A, and LAVImax. Conclusion: In aKD, impaired left atrial reservoir function could be detected as decreased PALS. For differentiating aKD from controls, PALS outperforms E/E', E/A, and LAVImax. However, like E/E', E/A, and LAVImax, PALS as a single parameter is limited in its clinical utility to differentiate aKD from controls because of its low sensitivity and poor discriminative ability. ( J Am Soc Echocardiogr 2018; 31: 323-32.)