Two‐dimensional systolic speckle tracking echocardiography provides a noninvasive aid in the identification of acute pediatric heart transplant rejection

Abstract

Background Acute rejection is an important cause of morbidity and mortality in the pediatric heart transplant (HT) population. A reliable noninvasive method for diagnosis of clinical rejection could substantially reduce these negative outcomes. Objective Evaluate left ventricular (LV) global longitudinal strain (GLS), and global circumferential strain (GCS) as early noninvasive indicators of acute pediatric HT rejection. Methods An 18‐month prospective cohort study involving 61 patients evaluated absolute change in peak global systolic strain (GLS and GCS) from enrollment (baseline) to next planned clinical encounter (follow‐up) or rejection. Acute rejection defined as a biopsy of grade ≥ 2R or treatment with enhanced immunosuppression by the transplant team, blinded to strain analysis. Two patient cohorts three months post HT without evidence of rejection at enrollment were identified. The study cohort experienced rejection. The control cohort remained free from rejection on follow‐up. Two‐way analysis of variance (ANOVA) models evaluated change in GLS and GCS by cohort group and time. Results Applying exclusion criteria, 51 patients enrolled in the control cohort and 10 in the study cohort. The study cohort's mean GLS declined 33% from baseline to rejection (P < .001) and mean GCS declined 16.6% (P = .021). No significant change from baseline to follow‐up was seen in the control cohort. A threshold absolute GLS value of 16.1% identified acute rejection with 100% sensitivity and 98% specificity (Likelihood Ratio, [LR] 51). Conclusion Noninvasive global longitudinal strain was sensitive and specific in the identification of acute clinical rejection in pediatric HT recipients.

Changes in circumferential strain can differentiate pediatric heart transplant recipients with and without graft rejection

“…A small, single center retrospective study showed a statistically significant decline in LS in 15 episodes of rejection in transplant patients one year after transplant 14 . Engelhardt et al identified a 33% decrease in global LS during episodes of acute clinical rejection in a small prospective study 15 …”

“…14 Engelhardt et al identified a 33% decrease in global LS during episodes of acute clinical rejection in a small prospective study. 15 The latter study only included rejection episodes that occurred at least three months from the time of transplant. Our results are in line with these previous studies and add the potential usefulness of circumferential strain in this population, particularly in the immediate post-transplant period.…”

Rejection surveillance in pediatric heart transplant recipients: Critical reflection on the role of frequent and long‐term routine surveillance endomyocardial biopsies and comprehensive review of non‐invasive rejection screening tools

“…Chanana et al also found that longitudinal, radial, and circumferential strain were reduced during rejection, and found that an average LV longitudinal systolic strain in apical 4‐chamber of < 14 predicted rejection with a sensitivity of 77% and specificity of 85% 70 . Engelhardt et al found that rejection (grade ≥2R or treated with enhanced immunosuppression) was associated with a significant decline in GLS from baseline value in their prospective study of 61 pediatric HT recipients 71 . A threshold absolute GLS value of 16.1% had 100% sensitivity and 98% specificity for detecting rejection.…”

“…70 Engelhardt et al found that rejection (grade ≥2R or treated with enhanced immunosuppression) was associated with a significant decline in GLS from baseline value in their prospective study of 61 pediatric HT recipients. 71 A threshold absolute GLS value of 16.1% had 100% sensitivity and 98% specificity for detecting rejection. Watanabe et al retrospectively evaluated echocardiographic right atrial strain indices in 36 pediatric HT recipients >1-year post-HT and found that right atrial function is decreased in patients with rejection, though the predictive power for rejection was not assessed.…”

Multimodality Imaging to Detect Rejection, and Cardiac Allograft Vasculopathy in Pediatric Heart Transplant Recipients—An Illustrative Review

“…Transplantology 2022, 3 245 GLS is sensitive and specific in identifying acute clinical rejection in pediatric HT recipients [6,[26][27][28][29]. Speckle tracking strain and strain rate imaging were also helpful in defining low-grade rejection in children after HT [30].…”