Prognostic value of left atrial strain in patients with tetralogy of fallot.

Abstract

To demonstrate prognostic utility of left atrial strain (LAS) in adult patients with repaired Tetralogy of Fallot (rTOF). Adults patients with rTOF were prospectively enrolled in this study between years 2011 and 2015. Left atrium (LA) phasic functions were assessed using 2D speckle tracking echocardiography. Association of LA strain (LAS) with primary (any cardiovascular event) and secondary (death, heart failure or arrhythmia) composite endpoints was assessed using Cox regression analysis. Hundred-and-twelve rTOF patients, in whom LAS was feasible and were in sinus rhythm, were included in the final analysis (age 33 ± 10years, 68[61%] male). Median duration of follow-up was 8.6 [4.2-9.7] years in the study group. Primary composite endpoint was reached in 48 patients (mean event-free survival time: 7.2 [6.6-7.9] years), and secondary composite endpoint was reached in 22 patients (mean event-free survival time: 8.7 [8.1-9.2] years). LA reservoir strain (LAS-r) was defined as tertile groups (1st tertile < 33%, 2nd tertile = 33-44%, 3rd tertile > 44%). Decreasing tertiles of LAS-r was associated with primary and secondary composite endpoints in Kaplan-Meier analysis (p = 0.02 and 0.002, respectively). In univariable Cox-regression, both decreasing LAS-r and LAS-r tertiles were associated with primary and secondary composite endpoints. Adjusted by initial repair age and NT-proBNP quartiles, increased LAS-r was associated with significantly decreased occurrence of experiencing any events (HR = 0.97, CI 0.93-0.99, p < 0.001). Decreasing LAS-r was still associated with primary endpoint when adjusted by left atrium volume index (LAVImax) (HR = 0.96, CI 0.92-0.99, p = 0.01), left ventricle global longitudinal strain (HR = 0.96, CI 0.93-0.99, p < 0.001) or right ventricle free wall longitudinal strain (HR = 0.96, CI 0.93-0.99, p = 0.03). Assessment of LA mechanics with the use of STE has incremental utility in determination of mortality and morbidity in rTOF, and may be implemented in clinical practice.