Quantitative adenosine real-time myocardial contrast echocardiography for detection of angiographically significant coronary artery disease.
BACKGROUND
Real-time (RT) myocardial contrast echocardiography (MCE) is a novel method for assessment of regional myocardial perfusion. We sought to evaluate the feasibility and diagnostic accuracy of quantitative adenosine RT MCE in predicting significant coronary stenoses, with reference to quantitative coronary angiography.


METHODS
Low-power RT MCE was performed in 43 patients scheduled for quantitative coronary angiography. Peak signal intensity (A), rate of signal intensity increase (beta), A x beta (myocardial blood flow), and their hyperemic reserves were estimated and compared with angiographic data.


RESULTS
The feasibility of quantitative stress RT MCE covering all coronary territories was 77% of patients with adequate baseline image quality. At rest we found no significant difference for any of the perfusion parameters between the normal and stenosed coronary territories. During hyperemia, beta and A x beta, but not A, increased significantly in normal coronary territories. In the regions subtended by significantly stenosed arteries, there were no significant increases in beta and A x beta. Receiver operating characteristic curves indicated that beta- and A x beta-reserves, but not A-reserve, could be sensitive parameters for detecting flow-limiting coronary stenosis in selected patients, particularly if significant left anterior descending coronary artery disease was involved.


CONCLUSIONS
Quantitative assessment of myocardial blood flow and its velocity reserve by RT MCE has the potential to detect significant coronary artery disease, but because of imaging and technical problems it is not yet robust enough for clinical use in unselected patients.
Malm
Siri
S
Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway. siri.malm@ntnu.no
Frigstad
Sigmund
S
Torp
Hans
H
Wiseth
Rune
R
Skjarpe
Terje
T
D000241:Adenosine; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003199:Computer Systems; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D004452:Echocardiography / Q000379:methods*; D005080:Exercise Test / Q000379:methods; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014665:Vasodilator Agents
D014665:Vasodilator Agents; D000241:Adenosine