Objective: To evaluate the accuracy and safety of pharmacologic stress testing with adenosine triphosphate (ATP) associated with thallium-201 scintigraphy for detection of coronary artery disease.
Patients: We studied 44 patients, 35 male and 9 female with a mean age of 59 + 9 years. Previous myocardial infarction was present in 15 patients. Thirty-two patients underwent coronariography that revealed coronary artery disease in 28 patients.
Methods: ATP (Stryadine) was infused at a rate of 140 micrograms/kg/min for 6 minutes and 2 mCi of thallium-201 was injected at the third minute. Stress and redistribution SPECT acquisitions were performed respectively 5-10 minutes and 4-6 hours after ATP infusion.
Results: The incidence of side effects was 77% and chest pain was the most frequent (45%). Dyspnea occurred in 2 patients and only one patient presented transient first degree AV block. No serious or severe side effect occurred. In patients without myocardial infarction 14 of 16 patients with significant coronary artery disease had reversible perfusion defects demonstrated by ATP thallium-201 scintigraphy (sensitivity 88%) and all of 4 patients without significant coronary artery disease had normal myocardial perfusion (specificity 100%). The overall accuracy for detecting the presence of coronary artery disease was 90%. The test demonstrated an overall accuracy of 88% for detecting left anterior descending artery disease, 91% for circumflex artery disease and 80% for right coronary artery disease.
Conclusions: Pharmacologic stress with ATP associated with thallium-201 scintigraphy, is a safe and high accurate alternative to dipyridamole and adenosine for the diagnosis of coronary artery disease.