Accuracy of dobutamine tetrofosmin myocardial perfusion imaging for the noninvasive diagnosis of transplant coronary artery stenosis.
BACKGROUND
Exercise stress myocardial perfusion scintigraphy has been used for the diagnosis of transplant coronary artery stenosis (TCAS) in cardiac allograft recipients. However, the role of pharmacologic stress myocardial perfusion imaging has not been evaluated. Aim of the study is to assess the accuracy of dobutamine stress 99m technetium tetrofosmin myocardial perfusion imaging for the diagnosis of TCAS in heart transplant recipients.


METHODS
We studied 50 patients (age 56 +/- 8 year, 45 men) at a mean of 6.4 +/- 2.8 years after cardiac transplant with dobutamine (up to 40 ìg/kg/min) stress 99m technetium tetrofosmin SPECT. Resting images were acquired 24 hours after the stress study. Significant TCAS was defined as > or =50% luminal diameter stenosis by coronary angiography.


RESULTS
Significant TCAS was detected in 30 patients (60%). Myocardial perfusion abnormalities (reversible and/or fixed defects) were detected in 27 of the 30 patients with and in 9 of the 20 patients without significant TCAS (sensitivity = 90%, CI 82-98, specificity = 55% CI 41-69, positive predictive value = 75%, CI 63-87, negative predictive value = 79%, CI 67-90 and accuracy = 76%, CI 64-88). Patients with multivessel TCAS had a larger stress perfusion defect score (5.6 +/- 3.1 vs 3.2 +/- 2.4, p < 0.05) compared to patients with single vessel TCAS. Among patients with abnormal perfusion who had no significant TCAS, 2 had lesions <50%, 2 had luminal irregularities and 5 had no abnormalities at angiography. Therefore specificity was 62% (8/13) in patients without any detectable angiographic abnormalities.


CONCLUSIONS
Dobutamine stress tetrofosmin myocardial perfusion imaging is a highly sensitive method for the detection of TCAS in recipients of cardiac allografts. The high negative predictive value of the test indicates that patients who demonstrate normal perfusion by this method may be excluded from further invasive studies.
Elhendy
A
A
Thoraxcenter and the Department of Nuclear Medicine, University Hospital, Rotterdam, the Netherlands. ElHendy.Abdou@Mayo.edu
Sozzi
F B
FB
van Domburg
R T
RT
Vantrimpont
P
P
Valkema
R
R
Krenning
E P
EP
Roelandt
J R
JR
Maat
L P
LP
Balk
A H
AH
D000368:Aged; D016001:Confidence Intervals; D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D004280:Dobutamine; D004562:Electrocardiography; D005080:Exercise Test / Q000379:methods; D005260:Female; D016027:Heart Transplantation / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011237:Predictive Value of Tests; D011336:Probability; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon; D014184:Transplantation, Homologous
D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D004280:Dobutamine; C078700:technetium tc-99m tetrofosmin