Abstract 11540: Predictive Ability of CAC and Myocardial Blood Flow: In a Real World Setting.

Background: Cardiac PET/CT myocardial perfusion imaging improves spatial resolution providing high quality images. Beyond the perfusion images for assessment of relative perfusion, Cardiac PET/CT also provides other ancillary data such as coronary artery calcium (CAC) and myocardial blood flow (MBF-ml/g/min) that broaden capability to assess and identify ischemia. These ancillary data generated with PET/CT are not available with SPECT. Presence or absence of CAC has been shown to predict major adverse cardiovascular events and assessment of CAC burden can be obtained along with MBF during PET/CT scanning. We analyzed how well CAC and MBF would predict 60-day revascularization. Methods: Retrospective analysis of PET/CT (Rb-82) scans utilizing regadenoson as a vasodilator were performed at a tertiary care center. Patients were symptomatic without prior history of coronary artery disease, referred for a PET/CT scan, and included a quantitative CAC. A total of 1504 patients were studied (female 43.4%; age 66.9 ±10.45 years). Revascularization was performed on 95 patients (6.3%). All scans were performed on a Siemens Biograph 16 scanner; all stress testing was done in accordance with appropriate use criteria. CAC and global MBF scores were assigned to quartiles for prediction. Logistic models using a combination of CAC and global MBF (Stress, Rest, and CFR (Coronary Flow Reserve)) to predict outcome of 60-day revascularization were constructed and the area under the curve (AUC) for these are reported. Results: Global stress MBF, CAC and CFR predicted 60-day revascularization similarly (AUC=0.72, 0.69, 0.71). They outperformed global rest MBF (AUC=0.56). CAC and stress MBF were both independently associated with revascularization, (p-value <0.0001). The combination of stress with MBF and CAC was significantly more predictive of 60 day revascularization (AUC=0.77) than stress MBF and CAC alone (p=0.001, p=0.0001 - DeLong's Test). Conclusions: Global stress MBF combined with CAC as obtained from PET/CT is more predictive for the identification of those that go on to revascularization than either alone. [ABSTRACT FROM AUTHOR]