Non-invasive detection of coronary artery stenosis: a comparison among power-Doppler contrast echo, 99Tc-Sestamibi SPECT and echo wall-motion analysis.
BACKGROUND
Power-Doppler imaging is a recently developed method for myocardial contrast echocardiography (MCE). It can selectively evaluate the signal coming from an ultrasound contrast agent, allowing myocardial perfusion studies.


OBJECTIVE
To compare the ability of power-Doppler MCE with stress-echo wall-motion and nuclear scan imaging (SPECT) to assess myocardial ischaemia during pharmacological stress, using coronary angiography as reference.


METHODS
In 25 patients the three non-invasive imaging modalities were acquired during a single dipyridamole stress test (so as to avoid stress variations). Power-Doppler MCE was acquired using continuous intravenous infusion of Levovist. Echo wall-motion was acquired too. At peak stress 99Tc-Sestamibi was injected; stress SPECT images were acquired 30 min after injection.


RESULTS
Power-Doppler MCE and SPECT showed 84% concordance (21 of 25 patients; kappa=0.67) for detection of ischaemia. Concordance based on coronary artery territories for normal perfusion versus fixed defects versus reversible defects was 92% (69 of 75; kappa=0.81), with 100% for left anterior descending, 92% for right coronary artery and 84% for circumflex. Power-Doppler MCE had lower sensitivity than SPECT (89 versus 100%) but higher specificity (100 versus 88%) for identification of stenotic (> or = 70%) coronary arteries as assessed by angiography. Echo wall-motion analysis showed the lowest sensitivity (68%) with 100% specificity. Accuracy was 94% for both power-Doppler MCE and SPECT, and 83% for wall-motion analysis.


CONCLUSIONS
Power-Doppler MCE is a sensitive and specific method for identification of myocardial perfusion during pharmacological stress. Accuracy of power-Doppler MCE for stenotic coronary arteries appears to be slightly higher than stress-echo wall-motion and similar to SPECT.
Rocchi
Guido
G
Institute of Cardiology, University of Bologna, S. Orsola University Hospital, Via Massarenti 9, 40138 Bologna, Italy. guidorocchi@libero.it
Fallani
Francesco
F
Bracchetti
Giovanni
G
Rapezzi
Claudio
C
Ferlito
Marinella
M
Levorato
Maurizio
M
Reggiani
Letizia Bacchi
LB
Branzi
Angelo
A
D000368:Aged; D001158:Arteries / Q000000981:diagnostic imaging / Q000473:pathology; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000453:epidemiology; D023921:Coronary Stenosis / Q000175:diagnosis* / Q000453:epidemiology; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology; D004452:Echocardiography; D015150:Echocardiography, Doppler; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015425:Myocardial Reperfusion; D015588:Observer Variation; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi