Abstract 2591: Changes in Referral Patterns for Cardiac CT Before and After Publication of the Appropriateness Criteria for the Use of Cardiac Computed Tomography
Background: The Appropriateness Criteria guidelines for cardiac computed tomography (CT) published by multiple medical societies in 2006 define appropriate, inappropriate, and uncertain indications for the use of CT in cardiac imaging. We evaluated changes in the utilization of cardiac CT at a large academic medical center before and after publication of the Appropriateness Criteria.
Methods: We retrospectively reviewed all patients who underwent a cardiac CT exam at our institution during the first two months of 2006 and 2007. The indication for performing each exam was determined from the ordering physician’s note and the patient’s medical records. The indication for each study was graded as Appropriate, Inappropriate, or Uncertain based on the Appropriateness Criteria. CT exams for evaluation of the aorta or peripheral vasculature were excluded.
Results: We evaluated 863 patients who underwent a cardiac CT exam during the study period. The number of cardiac CT exams that were considered ``Appropriate” increased from 76% in 2006 to 85% in 2007; p=0.001. There was a corresponding decrease in the number of CT exams that were considered ``Inappropriate” (12% in 2006 to 5% in 2007; p=0.001). The majority (91%) of the ``Inappropriate” exams were coronary CT angiograms done in patients with a previously normal stress test or for screening due to multiple cardiac risk factors. There was no significant difference in the number of exams for which the indication was considered ``Uncertain” (12% 2006, 10% 2007; p=0.19). The most common types of exams with an ``Uncertain” indication included evaluation of bypass graft patency, evaluation of patients with chest pain who were able to exercise and had interpretable EKG’s, and evaluation of native and prosthetic cardiac valves in patients with limited echocardiograms.
Conclusion: After publication of the Appropriateness Guidelines for Cardiac Computed Tomography, there has been a significant increase in the number of CT exams with an indication that was considered ``Appropriate”, with a corresponding decrease in the number of ``Inappropriate” exams. CT exams with an ``Uncertain” indication often fell into areas of active research in cardiac CT.