Contemporary use of Tc-99m stress-only SPECT myocardial perfusion imaging with attenuation correction: Defining strategies in clinical practice

599 Objectives To improve laboratory efficiency and minimize radiation exposure, stress-only (SO) myocardial perfusion imaging (MPI) with attenuation correction (AC) has been proposed and validated. To date, the routine implementation of SO MPI in clinical practice has not been described. The aim of this study was to compare demographics and perfusion abnormalities in patients undergoing either SO or rest/stress (R/S) MPI. Methods We evaluated 10,205 consecutive patients who underwent either SO or same-day R/S MPI within a 16 mnth period at 2 labs. Images were interpreted using ASNC models. Summed stress scores (SSS) were calculated for each patient and SSS>0 was defined as abnormal scan. Demographics, risk factors and SSS differences were compared between the SO and R/S groups by chi square analysis. Results Thirty percent (3035/10205) of patients underwent SO MPI: they were significantly younger, had a lower prevalence of CAD and diabetes. There were significantly more normal studies in SO. Mean SSS was significantly lower in SO. Conclusions In the 2 laboratories, stress-only SPECT MPI with AC is being utilized frequently in a patient population distinct from those undergoing rest-stress SPECT. This more efficient protocol with lower radiation exposure appears appropriate given the lower-risk profile and high percent of normal scans in this population. Research Support GE Healthcar