Feasibility and interpretation of global longitudinal strain imaging in pediatric heart transplant recipients

Abstract

Evaluation of myocardial mechanics after heart transplant is important in monitoring allograft function and identifying rejection. Speckle tracking global longitudinal strain (GLS) may be more sensitive to early regional changes from rejection. This study aimed to determine feasibility of GLS in pediatric hearts during surveillance echocardiograms, compare their GLS to published norms (-18% to -22%), and assess association of GLS with other indices of graft function. Retrospective review of transplant echocardiograms from 2013 to 2014. Philips QLAB was used for post-acquisition GLS analysis. Multiple linear regression was used to assess the association of GLS with echocardiographic/catheterization indices, and B-type natriuretic peptide (BNP). Forty-seven patients (84 studies) were included. Calculation of GLS was feasible in 82 studies (97%) with inter- and intra-observer variability of 0.71 and 0.69. Patients (n=9) with rejection had GLS of -16.4% (SD=3.5%) compared to those without [-16.8% (SD=3.7%)]. GLS worsened linearly with increasing Ln(BNP) (P=<.001), left ventricular volume in diastole (P=<.001), septal a' wave (P=<.001), and pulmonary capillary wedge pressure (P=<.001). Speckle tracking-based GLS is feasible and reproducible in pediatric heart recipients and is reduced at baseline. The role of GLS and BNP in detecting early systolic dysfunction warrants further investigation.

Defining normal: A necessary step in interpreting strain data in pediatric heart transplant recipients

“…At the same time, this study also demonstrates some of the limitations of strain and strain rate data in the clinical arena. Consistent with other analyses of strain data in pediatric heart transplant recipients, interobserver reliability was fair to good for the parameters assessed. In addition, there was significant variability on the patient level from year to year, which complicates distinguishing a clinically important change from simple noise.…”

Left ventricular adaptation following orthotopic heart transplantation in children: A speckle tracking echocardiographic imaging study

“…[13][14][15][16][17][18][27][28][29][30][31] Several studies have shown that strain parameters are abnormally low during an acute rejection episode. 14,30,32 In a study by Sehgal…”

Predictive Parameters of Decreased Left Ventricular Global Longitudinal Strain at 1 Month After Pediatric Heart Transplantation

“…Wisotzkey et al reported that higher log-BNP levels were associated with decreased LVGLS following pediatric heart transplant [17]. In their study, the data collection period was not specified.…”

“…However, the interpretation of strain/SR values requires knowledge of the potential range in values under stable conditions, without allograft rejection or CAV. Pediatric heart transplant recipients were reported to have lower LV global 1 3 longitudinal strain (LVGLS) values [16,17] than adult recipients; adult LVGLS values were in the normal range and not different from controls [18,19]. Several reports with serial follow-up strain/SR data in pediatric recipients without allograft rejection or CAV showed a pattern in which the LVGLS was decreased at 1 month and recovered over 1-2 years [20,21].…”