COMPARISON OF ADENOSINE AND TREADMILL EXERCISE THALLIUM-201 STRESS TESTS FOR THE DETECTION OF CORONARY ARTERY DISEASE

To determine the clinical usefulness of adenosine Tl-201 imaging for the evaluation of coronary artery disease, 22 patients with suspected coronary artery disease who underwent adenosine and exercise Tl-201 single photon emission computed tomography (SPECT) were studied. The peak levels of heart rate (83 vs 123 bpm, p< 0.001), systolic blood pressure (124 vs 164 mmHg, p< 0.001), diastolic blood pressure (70 vs 86 mmHg, p< 0.01) and rate pressure products (10220 vs 20410 bpm × mmHg, p< 0.001) were markedly smaller during adenosine infusion than during exercise. Segmental agreements between adenosine and exercise tests were 90% (218 of 242 segments) regarding the presence of perfusion defects and 89% (215 of 242 segments) regarding the presence of redistribution. Regional Tl-201 defects during adenosine testing were closely correlated with those of exercise testing. Adenosine and exercise tests showed similar sensitivities for the identification of individual coronary stenosis (85% vs 78%). However, in patients who were unable to perform adequate exercise (maximal heart rate < 120 bpm), the sensitivity of adenosine imaging tended to be higher than that of exercise imaging (92% vs 69%, p=0.07) Adenosine Tl-201 imaging is an alternative to the exercise test for assessing the severity and loci of coronary artery disease, especially in patients who are unable to perform adequate physical exercise.