Abstract 2787: Underutilization Outnumbers Overutilization of Myocardial Perfusion Imaging: A Consecutive Referral Analysis In Outpatient Clinics
BACKGROUND: Increasing use of SPECT Myocardial Perfusion Imaging (MPI) has led to the perception of MPI as an overutilized procedure in the US. However, this impression is primarily based on higher MPI utilization compared to other imaging modalities. Furthermore, previous studies did not include non-referred patients, and established guidelines were not used to assess appropriateness.
OBJECTIVE. We sought to analyze MPI utilization patterns in real world practice using the ACC/AHA/ASNC MPI Clinical Practice Guidelines (CPG) (2003) and Medicare reimbursement guidelines (MRG) as the gold standard in assessing MPI referral appropriateness.
METHODS: This retrospective study included 624 consecutive outpatients (50 excluded for incomplete data) from the Cardiology, Internal (IM), and Family Medicine (FM) clinics over a two-week period. Indicated referrals for MPI were defined as those meeting both CPG and MRG criteria without any non-invasive diagnostic testing or intervention during the prior 12 months. Overutilization was defined as not indicated & referred and underutilization as indicated & not referred.
RESULTS: Out of a total of 574 patients, (mean age 58 ±15 yrs, mean Framingham score 9.9 ± 7.3, 53% male, 23% coronary disease, 21% diabetes), 474 (83%) were appropriate and 100 (17%) inappropriate. Further analysis of only non-indicated patients showed that 17/450 (4%) were overutilized. In addition, analysis of only indicated patients showed that 83/124 (67%) were underutilized. Underutilization was higher than overutilization in all groups (p<0.001) and lower in Cardiology compared to IM or FM (p<0.001).
CONCLUSION: This is the first study to systematically analyze MPI referral patterns based on guidelines in a real world practice setting. It suggests that MPI is underutilized in both general and specialty practice. Further studies are needed to evaluate physician behavior and clinical outcomes related to the over and underutilization of MPI.