@article {Al Badarin510, author = {Firas Al Badarin and Timothy Bateman and John Spertus and Krishna Patel and Randall Thompson and Paul Chan}, title = {Changes in Prevalence of Ischemia over Time among Patients Referred for Myocardial Perfusion Imaging: PET vs. SPECT Comparison}, volume = {59}, number = {supplement 1}, pages = {510--510}, year = {2018}, publisher = {Society of Nuclear Medicine}, abstract = {510Background: A decline in test utilization and prevalence of inducible ischemia during single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) has been previously documented in several studies. However, positron emission tomography (PET) MPI is emerging as a valuable tool for evaluation of patients with suspected coronary ischemia. Determining whether similar temporal trends are also seen with PET MPI is exceedingly important, particularly in light of the differences between the 2 modalities in terms of diagnostic accuracy and referral patterns. Methods: Using the nuclear laboratory database at Saint Luke{\textquoteright}s Mid America Heart Institute (Kansas City, MO), we identified consecutive patients referred for clinically-indicated MPIs between 6/02 and 12/16, both with PET and SPECT. Patients with and without history of coronary artery disease (CAD) were included. Baseline characteristics were determined for patients referred to either modality. Presence of ischemia was determined by a nuclear cardiologist at the time of study interpretation. The proportion of ischemic studies was determined for each modality and tracked over time. Results: A total of 165,716 patients were included in this analysis, of whom 48,338 were tested with PET and 117,378 with SPECT. Overall, patients referred for PET MPI were older and with a higher burden of comorbidities compared to those referred to SPECT (Table). SPECT MPI utilization decreased from 6607 studies in 2002 to 4332 in 2016, while PET MPI volumes have increased from 460 to 4061 during the same time period. Additionally, the prevalence of ischemia has declined between 2002 and 2016 with both modalities (32.4\% to 20.7\% with PET and 23.3\% to 10.6\% with SPECT), with a more pronounced change seen with SPECT (55\% vs. 36\%). The proportion of studies with inducible ischemia was consistently higher with PET compared to SPECT at all-time points (Figure). Conclusion: In this single-center study, SPECT MPI utilization mirrors national trend while PET MPI volumes are more stable. The frequency of ischemic MPI studies has declined over time for both PET and SPECT, with a less marked decline observed in the PET group. Furthermore, the prevalence of ischemia was greater with PET compared to SPECT, likely reflective of the higher risk profile of tested patients. This is the first study to compare temporal trends of inducible ischemia during MPI directly between PET and SPECT.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/59/supplement_1/510}, eprint = {https://jnm.snmjournals.org/content}, journal = {Journal of Nuclear Medicine} }