Physiological assessment of coronary artery disease and myocardial viability in ischemic syndromes using adenosine echocardiography.
We hypothesized that it would be feasible and safe to use adenosine echocardiography to assess the physiological significance of coronary stenoses, detect ischemic myocardium, and assess myocardial viability in a high risk group of patients with coronary artery disease (CAD). Therefore, in 40 patients with either unstable angina, non-Q myocardial infarction, or myocardial infarction treated with thrombolytic therapy, we performed adenosine echocardiography (140 mug/kg per min for 5 mins with a 16 segment model for analysis) and compared the findings with quantitative planar thallium-201 scintigraphy, and (in 26 patients) coronary angiography.  The technique was safe, and there were no serious complications.  Adenosine resulted in a significant increase in heart rate and decrease in blood pressure.  The sensitivity of adenosine echocardiography and thallium scintigraphy were 96% and 88%, respectively, for detecting greater than 75% stenosis.  The change in echo score from baseline during adenosine infusion was significantly higher with more severe coronary disease (single vessel right coronary artery {RCA} or left circumflex {LCX} disease = 0.125 +/- 0.15, proximal left anterior descending coronary artery {LAD} disease = 0.23 +/- 0.15, RCA and LCX disease = 0.30 +/- 0.14, LAD and RCA and/or LCX disease = 0.62 +/- 0.13).  Likewise, the echo score during adenosine infusion was significantly higher in patients with high risk thallium scans (low risk = 1.29 +/- 0.26, medium risk = 1.74 +/- 0.22, and high risk = 2.21 +/- 0.37).  In 13 patients receiving thrombolytic therapy, adenosine echocardiography identified 12 with viable myocardium as defined by quantitative thallium criteria.  Furthermore, the wall-motion response of the viable segment was indicative of the degree of stenosis of the artery subtending the segment.  Regional function deteriorated in patients with high grade (95 +/- 2%) stenoses and improved in those with nonflow limiting stenoses (66 +/- 25%, P = 0.03).  Therefore, we conclude that adenosine echocardiography can detect significant coronary stenoses, has a high degree of concordance with thallium in detecting cardiac perfusion abnormalities, and can assess myocardial viability following thrombolytic therapy.
Department of Medicine, University of Virginia Health Sciences Center, Charlottesville.
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Buckmire
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McLaughlin
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Keller
D000241:Adenosine / Q000009:adverse effects; D000328:Adult; D000368:Aged; D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis* / Q000503:physiopathology; D004452:Echocardiography / Q000009:adverse effects / Q000379:methods* / Q000639:trends; D005080:Exercise Test / Q000379:methods*; D005260:Female; D005544:Forecasting; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium; D011877:Radionuclide Imaging; D012307:Risk Factors; D012680:Sensitivity and Specificity