Adenosine coronary vasodilation in coronary artery disease: Technetium- 99m tetrofosmin myocardial tomography versus echocardiography

This study compared the results of adenosine ^99mTc-tetrofosmin cardiac tomography with those of adenosine echocardiography in identifying patients with coronary artery disease (CAD) and in localizing individual stenosed coronary vessels. Methods: Twenty-six consecutive patients with suspected or known CAD had simultaneous adenosine (140 μg/Kg/min intravenously) ^99mTc-tetrofosmin tomography and two-dimensional echocardiography. All patients had coronary angiography within 4 wk from imaging studies. Regional ^99mTc-tetrofosmin activity was quantitatively measured in 78 coronary vascular territories and echocardiographic left ventricular function was assessed in corresponding regions. Results: At coronary angiography one patient had normal coronary vessels, 12 patients one-vessel and 13 had multivessel disease (≤50% luminal stenosis). Among the 25 patients with CAD, 22 showed perfusion defects at adenosine ^99mTc- tetrofosmin tomography (sensitivity 88%) and 17 had abnormal echocardiographic study (sensitivity 68%, p <0.05 versus ^99mTc- tetrofosmin). Agreement for the identification of patients with CAD between adenosine ^99mTc-tetrofosmin tomography and echocardiography was observed in 21 (81%) of the total 26 patients, with a kappa value of 0.45. Overall sensitivity, specificity and diagnostic accuracy for detection of individual stenosed vessels were 79%, 88% and 83% for ^99mTC tetrofosmin and 57%, 68% and 61% (all p <0.05 versus ^99mTc-tetrofosmin) for echocardiography. Concordance between adenosine ^99mTc-tetrofosmin tomography and echocardiography in the detection of individual stenosed coronary vessels was observed in 57 (73%) of the 78 vascular territories, with a kappa value of 0.36. Conclusion: Adenosine-induced coronary vasodilation associated with quantitative ^99mTc-tetrofosmin tomography is more accurate than adenosine echocardiography in identifying patients with CAD and in detecting individual stenosed coronary vessels.