Abstract 17187: Clinical Indications, Appropriateness, and Results of Repeat Myocardial Perfusion Imaging
Background: There has been a significant increase in myocardial perfusion imaging (MPI) exams performed. Appropriate use criteria (AUC) have been published to provide guidance in the use of MPI testing. However, limited data are available regarding the evaluation of AUC and how it relates to repeat MPI testing and MPI Results.
Hypothesis: We hypothesized that most repeat MPI exams would be performed for appopriate indications and sought to determine the timing between repeat MPI exams and their relation to AUC.
Methods: The electronic medical record was reviewed, including the MPI report with a listed indication as well as clinical notes and diagnostic codes. A single best indication for each test was identified, a MPI appropriate use classification was assigned based on current multisociety guidelines, and MPI results were recorded.
Results: Of 1097 patients undergoing index MPI, 424 underwent additional MPI. Median time between repeated MPI exams was 23.7 months. 56% of patients undergoing multiple MPI exams had 2 exams within 2 years of each other, and 28% had 2 MPI exams within 1 year of each other. The most common indications for repeat testing were recurrent chest pain and/or dyspnea in patients with known coronary heart disease (CHD) and recurrent chest pain and/or dyspnea in patients without known CHD, accounting for 36% and 19% of repeat MPI exams respectively. Repeat tests were more likely to demonstrate ischemia (36% vs. 24%, p<0.001) or scar (25% vs. 14%, p<0.001) than initial tests. 97.3% of all MPI exams were successfully assigned an AUC level. Of these, 15.1% were classified as inappropriate. 20.3% of initial MPI exams had an inappropriate AUC level assigned, vs. only 8.3% of repeat MPI exams. Inappropriate exams were less likely to demonstrate ischemia or scar than appropriate or uncertain exams (12.6% vs. 45.5%, p<0.001).
Conclusions: We observed a high prevalence of multiple MPI testing, although most repeat exams were performed for appropriate indications. An inappropriate AUC level was more commonly assigned to an initial MPI exam and more likely to yield a normal result on the MPI exam. New strategies are needed to minimize multiple testing and its attendant radiation burden, while ensuring appropriate diagnosis and risk stratification from MPI.
- © 2010 by American Heart Association, Inc.