Temporal trends in utilization of cardiac computed tomography

Background: Appropriate, inappropriate, and uncertain indications for the use of cardiac computed tomography (CT) were defined by a multisociety document in 2006. We sought to compare the appropriateness of cardiac CT examinations before and after these criteria were published. Methods: We retrospectively evaluated all patients presenting for cardiac CT examinations in the first 3 months of 2006 and 2007 at a large academic medical center and an unaffiliated large cardiology group private practice. The indication for the examinations were determined from the patients' medical records. The examinations were then classified as "appropriate," "inappropriate," or "uncertain," based on appropriateness criteria. Examinations that did not fall into any of these categories were classified as "uncategorized.". Results: We evaluated a total of 1409 patients (64.9% men; mean age, 57.6 ± 13.4 years). The proportion of appropriate CT examinations increased from 69.5% during the study period in 2006 to 78.5% in 2007 (P = 0.001). A corresponding decrease was observed in inappropriate CT examinations from 11.5% in 2006 to 4.6% in 2007 (P = 0.001). No change was observed in the number of CT examinations that were deemed uncertain (12.7% in 2006, and 13.3% in 2007; P = NS). Conclusion: The number of CT examinations considered appropriate increased during the study period, whereas the number of inappropriate examinations decreased. Cardiologists were more likely than noncardiologists to order examinations that were appropriate during the study period.