Diagnostic accuracy of regadenoson stress Rb-82 myocardial perfusion PET/CT in patients with suspected coronary artery disease

Objectives To investigate whether regadenoson provides diagnostic accuracy comparable to traditional pharmacological stress agents on Rb-82 myocardial perfusion PET.

Methods All patients had rest/stress Rb-82 myocardial perfusion PET. Regadenoson (0.4 mg) was administered as a bolus injection over 10 seconds followed by a 5-ml saline flush. The Rb-82 generator was started immediately after the saline flush. A Siemens Biograph-40 PET/CT scanner was used for acquisition. 51 consecutive patients without prior history of coronary artery disease (CAD) were enrolled. 27 (10 men, mean age 47 ± 10 years) had low likelihood (LLK) of CAD based on age, symptom classification, and absent coronary artery calcium. 24 (14 men, mean age 64 ± 10) had coronary angiography within 2 months of myocardial perfusion PET. The PET images were scored by consensus of 2 blinded readers on a 5-point scale using a 17-segment left ventricular model. Each segment was assigned to 1 of 3 vascular territories. A segmental score ≥ 2 was considered abnormal. Coronary angiography was used as the gold standard. Obstructive CAD was defined as >50% luminal stenosis in the left main, and >70% in the LAD, LCX, and RCA.

Results All 27 patients with LLK of CAD had normal PET, yielding a normalcy rate of 100%. The mean summed stress score in patients with obstructive CAD was 13 ± 9 and was 0.7 ± 2.3 in patients with nonobstructive CAD (p<0.01).

Conclusions Preliminary data suggest that regadenoson provides high diagnostic accuracy with Rb-82 myocardial perfusion PET. The simplicity of a fixed-dose bolus administration makes it an attractive alternative to traditional pharmacological stress agents.