Value of Dobutamine Technetium-99m-Sestamibi SPECT and Echocardiography in the Detection of Coronary Artery Disease Compared with Coronary Angiography

The value of dobutamine echocardiography and 99mTc-sestamibi SPECT imaging was evaluated as a noninvasive diagnostic method for assessing coronary artery disease (CAD). Twenty-seven patients who underwent coronary angiography were submitted to two separate injections of 99mTc-sestamibi, one under control conditions and the other after reaching a peak dobutamine infusion rate. Simultaneous ECG and echocardiographic monitoring was also performed during stepwise dobutamine infusion. Whereas the overall sensitivity and specificity of dobutamine sestamibi SPECT imaging were 94% and 88%, these values for dobutamine ECG and echocardiography were 61%, 55% and 84%, 88%, respectively. When dobutamine echocardiography and 99mTc-sestamibi SPECT imaging were evaluated together, the diagnostic accuracy reaches almost 100%. Dobutamine echocardiography is of value in determining ischemic threshold earlier than clinical symptoms and allows simultaneous evaluation of ventricular performance and contractile function associated with perfusion abnormalities on 99,Tc-sestamibi SPECT imaging. Our experience shows that 99mTc-sestamibi SPECT imaging, when combined with dobutamine echocardiography, is a safe, practical, well tolerated method with high diagnostic accuracy for the evaluation of CAD.