Abstract 18606: The Value of Cardiac Magnetic Resonance Imaging in Detection of Sub-Clinical Cellular Rejection
Background: Sub-clinical acute cellular rejection (ACR) after heart transplantation (HTx) is a major cause of cardiac allograft vasculopathy. But with endomyocardial biopsy (EMB) the detection of sub-clinical ACR is limited by sampling error, interobserver variability or the wide variability of frequency and duration to use this invasive interventional tool. Thus, we used cardiac magnetic resonance imaging (CMRI) to identify sub-clinical ACR after HTx.
Methods: In total 73 patients with a mean age of 53±12 years were scanned 167 times with a 1.5T-MRI scanner using a standard myocarditis protocol to detect sub-clinical ACR. Myocardial edema and myocyte damage were determined by using specific “cut-off” values to determine inflammatory parameters of early- and delayed- enhancement as well as to determine water content. CMRI-results were correlated with results of EMB performed on the same day using the original ISHLT EMB guidelines to more accurately determine sub-clinical ACR.
Results: In 87 (52%) out of 167 biopsies a rejection grade of 1A was diagnosed, whereas 16 biopsies (10%) were graded 1B, 2 biopsies (1.1%) 2A and 1 biopsy (0.5%) 3A, respectively. No rejection was diagnosed in 61 biopsies (36%).
Sensitivity, specificity and negative predictive value for rejection grade ≥1B were for (1) early-enhancement 64%, 70% and 93%; (2) delayed-enhancement 43%, 38% and 82%; (3) water content: 60%, 79% and 93%. In combination of all 3 parameters sensitivity, specificity and negative predictive value were: 71%, 66% and 94%.
Conclusion: We showed that a combination of specific CMRI parameters have a high negative predictive value in early detection of sub-clinical ACR. Future clinical studies need further to evaluate CMR as an evolving tool in ACR.
- © 2013 by American Heart Association, Inc.