Decreased [99mTc]Sestamibi uptake with dobutamine versus dipyridamole stress.
OBJECTIVE
Animal studies suggest an interference of dobutamine on [99mTc]sestamibi uptake. In this study dobutamine was compared to dipyridamole rest-stress [99mTc]sestamibi uptake ratio (UR).


METHODS
Twenty-five patients with suspect coronary artery disease (CAD) underwent rest, dobutamine, and dipyridamole [99mTc]sestamibi SPECT at 24-h intervals and coronary angiography. UR was calculated separately for each coronary territory considering injected dose and acquisition delay.


RESULTS
There were 38 CAD territories in 20 patients. On a patient basis, dipyridamole SPECT sensitivity was 85%, versus 70% for dobutamine. On a territory basis, sensitivity was 66% versus 42% (P<0.05), and specificity 92% versus 86%, respectively for dipyridamole versus dobutamine. In the 38 CAD territories, dipyridamole UR was -4.1+/-29.4%, and dobutamine UR was -13.1+/-19.9% (P<0.05). In the 37 no-CAD territories, UR was 34+/-23.6% for dipyridamole and -0.4+/-17.8% for dobutamine (P<0.0001). UR difference between CAD versus no-CAD territories was larger using dipyridamole (P<0.0001) than dobutamine (P<0.005).


CONCLUSIONS
The UR comparison confirms that [99mTc]sestamibi uptake underestimates the blood flow heterogeneity induced by dobutamine more than that produced by dipyridamole.
Sciagrà
R
R
Nuclear Medicine Unit, Department of Clinical Physiopathology, University of Florence, Italy. r.sciagra@dfc.unifi.it
Zoccarato
O
O
Bisi
G
G
Pupi
A
A
D000368:Aged; D002138:Calibration; D015331:Cohort Studies; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000188:drug therapy; D004176:Dipyridamole / Q000493:pharmacokinetics*; D004280:Dobutamine / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi / Q000493:pharmacokinetics*; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
D004280:Dobutamine; D004176:Dipyridamole; D017256:Technetium Tc 99m Sestamibi