A comparison of myocardial perfusion and rejection in cardiac transplant patients.
BACKGROUND
Although histological evaluation of the cardiac tissue is the current gold standard for evaluation of rejection, we hypothesized that cardiac perfusion MRI is a safe non-invasive method that correlates tissue blood flow changes with biopsy proven rejection in the cardiac transplant patient.


METHODS
In a retrospective study from 1984-2001, 83 patients underwent 135 MR Gd-DTPA imaging studies. In 8 patients (9%), biopsies graded 2 or higher (by ISHLT criteria) provided evidence of rejection. Patients were age and sex matched to 11 non-rejected controls for imaging analysis. Time-signal intensity curves generated for a mid-ventricle LV short axis slice during rest and adenosine stress allowed determination of myocardial blood flow (MBF, ml/min/gm). ROC curve analysis by SPSS allowed estimation of sensitivity and specificity.


RESULTS
At rest, there was no difference in MBF between patients with prior rejection vs. those without (1.18 +/- 0.26 vs. 1.16 +/- 0.29). At stress there was a decrease in MBF for patients with prior rejection episodes (3.27 +/- 0.74) compared to no rejection (3.60 +/- 0.72), P = 0.067). The area under the ROC curve was 0.82, with specificity and sensitivity of 75% and 81%, respectively.


CONCLUSIONS
This study suggests that perfusion MR imaging can be used in assessing the cardiac transplant patient for rejection related microvascular changes. The high specificity and sensitivity recorded from the ROC curve illustrates the potential utility of this diagnostic test for future studies.
Rivard
Andrew L
AL
Department of Surgery, Experimental Surgical Services, University of Minnesota, MMC 220, 420 Delaware Street SE, Minneapolis, MN 55455, USA. rivar011@umn.edu
Swingen
Cory M
CM
Blake
Donnevan
D
Huang
Andrea S
AS
Kanth
Pooja
P
Thomsen
Grete F
GF
Cordova
Erin J
EJ
Miller
Leslie W
LW
Bianco
Richard W
RW
Wilke
Norbert
N
D000368:Aged; D003287:Contrast Media; D003326:Coronary Circulation; D005240:Feasibility Studies; D005260:Female; D019786:Gadolinium DTPA; D006084:Graft Rejection / Q000473:pathology* / Q000503:physiopathology; D006331:Heart Diseases / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D016027:Heart Transplantation; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome
D003287:Contrast Media; D019786:Gadolinium DTPA