Left ventricular myocardial performance index change for detection of acute cellular rejection in pediatric heart transplantation
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Updated: May 7, 2026
A Pre-Clinical Porcine Model of Orthotopic Heart Transplantation
Published on: April 27, 2019
Ryan Flanagan1, Nicole Cain, Gregory H Tatum
1Division of Pediatric Cardiology, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA; Womack Army Medical Center, Fort Bragg, NC, USA.
Abstract:
EMB, the gold standard for diagnosis of ACR, poses unique risks in children. Limited cross-sectional data have associated LV MPI with ACR. We hypothesize that a relative change in MPI from baseline without ACR to the time of ACR will better detect ACR than an absolute threshold LV MPI value. We identified 40 children with ACR ≥60 days post-transplant matching them by age and time from transplantation to 40 children without ACR. There was a significant increase in LV MPI at time of ACR vs. baseline (0.59 ± 0.17 vs. 0.41 ± 0.11; p < 0.001). There was no difference in LV MPI between baseline and follow-up (0.41 ± 0.11 vs. 0.42 ± 0.11; p = 0.65). An absolute increase in LV MPI of ≥0.47 had 82.5% sensitivity and 85% specificity for ACR, whereas an increase in LV MPI from baseline of ≥20.4% was 90% sensitive and 100% specific. Serial measurement of LV MPI appears to be a sensitive and specific marker of ACR. LV MPI shows good interobserver agreement and increases at the time of EMB-proven ACR with subsequent resolution to baseline measurements upon EMB-proven resolution of ACR. Future studies in larger, prospective cohorts should be undertaken to validate these findings.
Insights
Serial measurement of myocardial performance index (MPI) in children undergoing heart transplantation can effectively detect acute cellular rejection (ACR). A relative increase in LV MPI is more sensitive and specific than an absolute value for diagnosing ACR.
Area of Science:
- Pediatric Cardiology
- Transplant Medicine
- Cardiac Imaging
Background:
- Endomyocardial biopsy (EMB) is the standard for diagnosing acute cellular rejection (ACR) in pediatric heart transplant recipients but carries risks.
- Previous studies suggest a link between left ventricular myocardial performance index (LV MPI) and ACR, but data are limited.
- The diagnostic utility of absolute versus relative changes in LV MPI for ACR requires further investigation.
Purpose of the Study:
- To determine if a relative change in LV MPI from baseline predicts acute cellular rejection (ACR) in pediatric heart transplant recipients.
- To compare the sensitivity and specificity of relative LV MPI change versus absolute LV MPI thresholds for ACR detection.
- To assess the role of serial LV MPI measurements in monitoring ACR and its resolution.
Main Methods:
- Retrospective analysis of 40 pediatric heart transplant recipients with ACR (≥60 days post-transplant) and 40 matched controls without ACR.
- Comparison of LV MPI values at baseline (pre-ACR) and at the time of ACR diagnosis.
- Calculation of sensitivity and specificity for both absolute LV MPI thresholds and relative percentage increase in LV MPI for ACR detection.
Main Results:
- LV MPI significantly increased at the time of ACR compared to baseline (0.59 ± 0.17 vs. 0.41 ± 0.11, p < 0.001).
- An absolute LV MPI increase of ≥0.47 showed 82.5% sensitivity and 85% specificity for ACR.
- A relative LV MPI increase of ≥20.4% from baseline demonstrated 90% sensitivity and 100% specificity for ACR, outperforming absolute values.
Conclusions:
- Serial LV MPI measurements are a sensitive and specific non-invasive marker for detecting acute cellular rejection (ACR) in pediatric heart transplant recipients.
- A relative increase in LV MPI is a more accurate indicator of ACR than an absolute LV MPI threshold.
- LV MPI demonstrates good interobserver agreement and resolves to baseline levels upon ACR resolution, supporting its use in monitoring.
