Diagnostic accuracy of dipyridamole technetium 99m-labeled sestamibi myocardial tomography for detection of coronary artery disease

Background

The diagnostic accuracy of exercise ^99mTc-labeled sestamibi and intravenous dipyridamole ²⁰¹Tl-labeled myocardial tomography is established. The accuracy of dipyridamole stress ^99mTc-labeled sestamibi myocardial tomography for the detection of coronary artery disease has not been reported.

Methods and Results

Our purpose was to determine the diagnostic accuracy of same-day, rest-dipyridamole stress ^99mTc-labeled sestamibi myocardial single-photon emission computed tomography (SPECT) compared with coronary angiography. Two hundred forty-four patients who were unable to exercise adequately underwent both dipyridamole ^99mTc-labeled sestamibi SPECT and coronary angiography within 6 months. Dipyridamole was administered intravenously in a standard dose of 0.56 mg/kg for 4 minutes. Cardiac and noncardiac side effects were recorded. The presence of coronary stenoses of 50% or greater diameter reduction in each of the major coronary arteries was compared with imaging data in corresponding myocardial perfusion beds. The patient population was predominately (98.8%) male with a mean age of 63±9 years (range 33 to 83 years). The majority of patients had stable angina (88%). Eighty-four patients (35%) gave a prior history of myocardial infarction; 44 patients (18%) had a history of congestire heart failure. The principal limitation to exercise stress was peripheral vascular disease in 62 patients (26%). No serious side effects occurred during dipyridamole stress; 14% of patients had chest pain and 8% of patients had 1 mm or greater ST segment depression. Of the 204 patients with documented coronary stenoses, 43 (21%) had single-vessel disease and 161 (79%) had multivessel disease. The sensitivity was 93% (40/43 in patients with single-vessel disease) and 91% (146/161 in patients with multivessel disease). Overall sensitivity was 91%. The specificity was 28% (11/40) in this population with a high prestest probability of coronary artery disease and posttest referral for cardiac catheterization.

Conclusion

^99mTc-labeled sestamibi myocardial tomography in conjunction with intravenous dipyridamole stress is a safe and sensitive method for the detection of coronary artery disease. The diagnostic accuracy of dipyridamole stress ^99mTc-labeled sestamibi SPECT for the detection of coronary artery disease is similar to that reported for exercise stress ^99mTc-labeled sestamibi tomography, making this a suitable alternative for the evaluation of patients who are unable to exercise adequately.