Detection of obstructive coronary artery disease using regadenoson stress and 82Rb PET/CT myocardial perfusion imaging

Abstract

Our objective was to study the diagnostic performance of regadenoson (82)Rb myocardial perfusion PET imaging to detect obstructive coronary artery disease (CAD).

Methods: We studied 134 patients (mean age, 63 ± 12 y; mean body mass index, 31 ± 9 kg/m(2)) without known CAD (96 with coronary angiography and 38 with low pretest likelihood of CAD). Stress left ventricular ejection fraction (LVEF) minus rest LVEF defined LVEF reserve. The Duke score was used to estimate the anatomic extent of jeopardized myocardium.

Results: Regadenoson PET had a high sensitivity, 92% (95% confidence interval [CI], 83%-97%), in detecting obstructive CAD, with a normalcy rate of 97% (95% CI, 86%-99%), specificity of 77% (54/70 patients; 95% CI, 66%-86%), and area under the receiver-operator-characteristic curve of 0.847 (95% CI, 0.774-0.903; P < 0.001). Regadenoson PET demonstrated high sensitivity to detect CAD in patients with single-vessel CAD (89%; 95% CI, 70%-98%). The mean LVEF reserve was significantly higher in patients with normal myocardial perfusion imaging results (6.5% ± 5.4%) than in those with mild (4.3 ± 5.1, P = 0.03) and moderate to severe reversible defects (-0.2% ± 8.4%, P = 0.001). Also, mean LVEF reserve was significantly higher in patients with a low likelihood of CAD (7.2% ± 4.5%, P < 0.0001) and mild or moderate jeopardized myocardium than in those with significant jeopardized myocardium (score ≥ 6), -2.8% ± 8.3%.

Conclusion: Regadenoson (82)Rb myocardial perfusion imaging is accurate for the detection of obstructive CAD. LVEF reserve is high in patients without significant ischemia or significant angiographic jeopardized myocardium.

Keywords: 82Rb; coronary angiography; diagnostic accuracy; ejection fraction; regadenoson.

FIGURE 1

Rest–stress regadenoson ⁸²Rb PET/CT protocol. After scout CT acquisition (120 kVp, 10 mA), CT transmission scan (CTAC) (140 kVp, 10 mA, pitch of 1.35) was acquired. Patients received 1,480–2,220 MBq of ⁸²Rb intravenously at rest, and emission images were acquired in 2-dimensional list mode. After rest imaging, patients remained in scanner gantry for stress imaging. Stress was induced with 0.4 mg of regadenoson given intravenously over 10 s followed by 10-mL flush with normal saline. Immediately after saline flush, second dose of 1,480–2,220 MBq of ⁸²Rb was administered intravenously approximately 30 s after regadenoson injection and emission images were acquired as previously described. Ordered-subsets expectation maximization (30 iterations and 2 subsets) and 3-dimensional PET filtering (Butterworth filter, cutoff frequency of 10, order of 5) were used for reconstruction of images.

FIGURE 2

Rest and regadenoson stress ⁸²Rb PET myocardial perfusion images demonstrate medium-sized region of severe reversible perfusion defects in mid anterior wall, septum, apical anterior wall, apical septum, apical inferior wall, and apex, with transient cavity dilation. Coronary angiogram confirmed severe obstructive CAD in left anterior descending, left circumflex, and right coronary arteries.

FIGURE 3

Rest and regadenoson stress ⁸²Rb PET myocardial perfusion images demonstrate large region of severe reversible perfusion defect in entire inferior and inferolateral walls and basal inferoseptal region. Coronary angiogram demonstrated occluded left circumflex and right coronary arteries, without significant disease in left anterior descending coronary artery.

FIGURE 4

Changes in left ventricular volumes and ejection fraction from rest to regadenoson stress ⁸²Rb MPI. EDV = end-diastolic volume; ESV = end-systolic volume.

FIGURE 5

Regadenoson LVEF reserve as function of relative MPI results. Mod = moderate.

FIGURE 6

Regadenoson LVEF reserve as function of Duke Jeopardy Score. LLK = low likelihood.