Identification of hibernating myocardium with quantitative intravenous myocardial contrast echocardiography: comparison with dobutamine echocardiography and thallium-201 scintigraphy.
BACKGROUND
There are currently no data on the accuracy of intravenous myocardial contrast echocardiography (MCE) in detecting myocardial hibernation in man and its comparative accuracy to dobutamine echocardiography (DE) or thallium 201 (Tl(201)) scintigraphy.


RESULTS
Twenty patients with coronary artery disease and ventricular dysfunction underwent MCE 1 to 5 days before bypass surgery and repeat echocardiography at 3 to 4 months. Patients also underwent DE (n=18) and rest-redistribution Tl(201) tomography (n=16) before revascularization. MCE was performed using continuous Optison infusion (12 to 16 cc/h) with intermittent pulse inversion harmonics and incremental triggering (1:1 to 1:8). Myocardial contrast intensity (MCI) replenishment curves were constructed to derive quantitative MCE indices of blood velocity and flow. Recovery of function occurred in 38% of dysfunctional segments. MCE parameters of perfusion in hibernating myocardium were similar to segments with normal function and higher than dysfunctional myocardium without recovery of function (P<0.001). The best MCE parameter for predicting functional recovery was Peak MCIxbeta, an index of myocardial blood flow (area under the curve, 0.83). MCE parameters were higher in segments with contractile reserve and Tl(201) uptake > or =60% (P<0.05) and identified viable segments without contractile reserve by DE. The sensitivity of Peak MCIxbeta >1.5 dB/s for recovery of function was 90% and was similar to Tl(201) scintigraphy (92%) and any contractile reserve (80%); specificity was higher than for Tl(201) and DE (63%, 45%, and 54%, respectively; P<0.05).


CONCLUSIONS
MCE with intravenous contrast identifies myocardial hibernation in humans. Prediction of viable myocardium with MCE is best using quantification of myocardial blood flow and provides improved accuracy compared with DE and Tl(201) scintigraphy.
Shimoni
Sarah
S
Section of Cardiology, Department of Medicine, Baylor College of Medicine and the Methodist DeBakey Heart Center, Houston, Tex 77030, USA.
Frangogiannis
Nikolaos G
NG
Aggeli
Constadina J
CJ
Shan
Kesavan
K
Verani
Mario S
MS
Quinones
Miguel A
MA
Espada
Rafael
R
Letsou
George V
GV
Lawrie
Gerald M
GM
Winters
William L
WL
Reardon
Michael J
MJ
Zoghbi
William A
WA
D000368:Aged; D001783:Blood Flow Velocity; D003287:Contrast Media / Q000008:administration & dosage*; D003324:Coronary Artery Disease / Q000150:complications / Q000175:diagnosis / Q000601:surgery; D003326:Coronary Circulation; D004280:Dobutamine; D004452:Echocardiography; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D017682:Myocardial Stunning / Q000175:diagnosis* / Q000000981:diagnostic imaging; D015588:Observer Variation; D011237:Predictive Value of Tests; D012372:ROC Curve; D011877:Radionuclide Imaging; D020127:Recovery of Function; D012680:Sensitivity and Specificity; D013794:Thallium Radioisotopes; D018754:Ventricular Dysfunction / Q000175:diagnosis / Q000209:etiology
D003287:Contrast Media; D013794:Thallium Radioisotopes; D004280:Dobutamine