Objective: To 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.
Methods: The 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.
Results: The 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.
Conclusions: It 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.