OBJECTIVETo evaluate the feasibility, safety and diagnostic accuracy of pharmacologic stress of (99m)Technetium-MIBI single-photon emission computed tomography (SPECT) with intravenous adenosine triphosphate (ATP) in patients with suspected coronary artery disease.

METHODSThe study group included 263 patients who were suspected of having coronary artery disease. All patients underwent (99m)Tc-MIBI myocardial perfusion imaging with ATP infusion (0.16 mg/kg body weight per min for 5 min). 20 mCi of (99m)Tc-MIBI were injected 3 minutes after the start of ATP infusion. Myocardial SPECT images were obtained 60 minutes later. Then, two days later, 20 mCi of (99m)Tc-MIBI were administered at rest and myocardial SPECT was repeated. 51 patients also underwent coronary angiography within two weeks for evaluation of sensitivity and specificity of ATP-myocardial perfusion imaging in detection of coronary artery disease. The occurrence of cardiac and non-cardiac adverse effects was carefully monitored during and after intravenous ATP infusion.

RESULTSThe ATP infusion protocol was completed in all patients. Although 59% of the patients had various kinds of adverse effects, most of them were mild. No patient required aminophyline. The most severe adverse effect was second degree type II atria-ventricular block (4/263), but all events were transient. The sensitivity and specificity of ATP-myocardial perfusion imaging were 97% and 82%, respectively.

CONCLUSIONSIt is shown that (99m)Technetium-MIBI SPECT with intravenous ATP is a safe and feasible technique for detecting coronary artery disease in patients unable to perform the exercise test.