Cardiovascular Magnetic Resonance better diagnostic tool for Cardiac Transplant Rejection: JACC

Diagnostic efficacy of Cardiovascular Magnetic Resonance for Cardiac Transplant Rejection mapping revealed greater diagnostic accuracy than other Cardiac magnetic resonance (CMR) approaches in a new study done by Donghee Han and colleagues. Native T1 and ECV have a high diagnostic usage but a reduced diagnostic accuracy when compared to T2, which is mostly due to inferior specificity. LGE demonstrated poor diagnostic performance for rejection detection.

The findings of this study were published in Journals of the American College of Cardiology on 14th December, 2021.

The current gold standard for detecting acute cardiac transplant rejection is endomyocardial biopsy. CMR is uniquely capable of characterisation of cardiac tissue and may be effective as a noninvasive option for transplant rejection diagnosis. Therefore this study was conducted with an objective to evaluate the diagnostic efficacy of multiple CMR imaging parameters in assessing acute cardiac transplant rejection.

For the following study PubMed and Web of Science were searched for relevant papers reporting on the use of CMR myocardial tissue characterisation for acute cardiac transplant rejection diagnosis, with endomyocardial biopsy serving as the gold standard. Summary receiver-operating characteristic curves based on pooled sensitivity, specificity, and hierarchical modelling were generated.

The key results of this study stated as follow:

10 studies with a total of 564 patients were included from the 478 publications reviewed. 

The sensitivity and specificity for acute cardiac transplant rejection were 84.6 (95% CI: 65.6-94.0) and 70.1 (95% CI: 54.2-82.2) for T1, 86.5 (95% CI: 72.1-94.1) and 85.9 (% CI: 65.2-94.6) for T2, 91.3 (95% CI: 63.9-98.4) and 67.6 (95% CI: 56.1-77.4) for extracellular volume fraction (ECV (LGE). 

The areas under the summary receiver-operating characteristic curve based on hierarchical modelling were 0.84 (95% CI: 0.81-0.87) for T1, 0.92 (95% CI: 0.89-94) for T2, 0.78 (95% CI: 0.74-0.81) for ECV, and 0.56 (95% CI: 0.51-0.60) for LGE. 

T2 measurements had the best diagnostic accuracy, followed by native T1, ECV, and LGE (all P values for T1, ECV, and LGE versus T2 were 0.001).

Finally, T2 mapping had the best diagnostic accuracy for predicting rejection following heart transplantation.

Reference: 

Han, D., Miller, R. J. H., Otaki, Y., Gransar, H., Kransdorf, E., Hamilton, M., Kittelson, M., Patel, J., Kobashigawa, J. A., Thomson, L., Berman, D., & Tamarappoo, B. (2021). Diagnostic Accuracy of Cardiovascular Magnetic Resonance for Cardiac Transplant Rejection. In JACC: Cardiovascular Imaging (Vol. 14, Issue 12, pp. 2337–2349). Elsevier BV. https://doi.org/10.1016/j.jcmg.2021.05.008