Correlation of cardiovascular magnetic resonance imaging findings and endomyocardial biopsy results in patients undergoing screening for heart transplant rejection.
BACKGROUND
Endomyocardial biopsy (EMB) is the current gold standard to screen for heart transplant rejection but has important risks and limitations. Cardiovascular magnetic resonance imaging (CMRI) is increasingly used to characterize cardiac function and myocardial tissue. We evaluated the diagnostic accuracy of CMRI compared with EMB and clinically diagnosed heart transplant rejection.


METHODS
Comprehensive CMRI scans were performed on adult heart transplant recipients within 24 hours of EMB (routine or clinically indicated), before initiation of any anti-rejection therapy, and blinded to EMB results. Multivariable analysis was used to create CMRI diagnostic criteria for comparison with a positive EMB (Grade ≥ 2R or antibody-mediated rejection) and clinical rejection (change in medical therapy to treat rejection).


RESULTS
Sixty participants (75% male; mean age, 51 ± 14 years) were recruited, providing 73 comparisons between CMRI and EMB for the diagnosis of rejection. Multivariable logistic regression identified myocardial edema (T2 relaxation time) and right ventricular end-diastolic volume index as independent predictors of a positive EMB. Combining threshold right ventricular end-diastolic volume index and edema values predicted a positive EMB with very good accuracy: sensitivity, 93%; specificity, 78%; positive predictive value, 52%; and negative predictive valve, 98%. CMRI was more sensitive than EMB at predicting clinical rejection (sensitivity of 67% vs 58%).


CONCLUSIONS
CMRI has high sensitivity and high negative predictive value in predicting biopsy-positive heart transplant rejection and may be useful as a screening test before routine EMB. CMRI also has better sensitivity for clinically diagnosed heart transplant rejection and could be helpful in cases of negative rejection on the biopsy specimen.
Division of Cardiology, Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada.
Craig R
CR
Butler
Division of Cardiology, Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada.
AnaMaria
A
Savu
Patient Health Outcomes Research and Clinical Efficacy Unit.
Jeffrey A
JA
Bakal
Division of Cardiology, Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada.
Mustafa
M
Toma
Department of Biomedical Engineering.
Richard
R
Thompson
Department of Biomedical Engineering.
Kelvin
K
Chow
Division of Cardiology, Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada.
Harris
H
Wang
Division of Cardiology, Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada.
Daniel H
DH
Kim
Department of Laboratory Medicine and Pathology.
Michael
M
Mengel
Department of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada.
Mark
M
Haykowsky
Division of Cardiology, Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada.
Glen J
GJ
Pearson
Division of Cardiology, Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada.
Padma
P
Kaul
Division of Cardiology, Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada. Electronic address: ip3@ualberta.ca.
Ian
I
Paterson
D000328:Adult; D000416:Alberta / Q000453:epidemiology; D001706:Biopsy; D006328:Cardiac Catheterization; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000453:epidemiology / Q000473:pathology*; D016027:Heart Transplantation; D006801:Humans; D015994:Incidence; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D015203:Reproducibility of Results; D012189:Retrospective Studies
acute transplant rejection; cardiovascular MRI; heart transplantation