Cost-effectiveness of multidetector computed tomography compared with myocardial perfusion imaging as gatekeeper to invasive coronary angiography in asymptomatic firefighters with positive treadmill tests

Background: In a prospective evaluation of 3950 Los Angeles County firefighters who underwent wellness/fitness examinations, 495 firefighters had abnormal treadmill tests and were referred for cardiology evaluation. Cost of the traditional myocardial perfusion imaging (MPI) followed by invasive coronary angiography (ICA) was compared with a method incorporating 64-slice multidetector computed tomography (MDCT) with coronary calcium score (CCS) followed by computed tomographic angiography (CTA) and ICA as indicated. Objective: We compared the costs of 2 methods of predicting coronary artery disease (CAD) by ICA among asymptomatic patients with positive treadmill tests. Methods: A decision-analytic framework was used to compare the net direct costs of CAD diagnosis associated with MDCT versus MPI. In the MDCT arm, all received CCS followed by CTA for those with calcium scores>10 and ICA for those with ≥50% stenosis on CTA. For the MPI arm, results were estimated from prior years' experience, in which firefighters with abnormal treadmill results were referred to ICA. Results: Of 495 firefighters, 131 (26.9%) had abnormal CCS and went to CTA; 40 (8.1%) had ≥50% stenosis on CTA and went to ICA. According to prior years' experience with MPI, 146 (29.5%) would have shown abnormalities requiring ICA. Average cost was $1376/person for MPI versus $503/person for CCS with or without CTA as gatekeeper. All sensitivity analyses showed lower costs for the MDCT pathway compared with MPI. Conclusion: In this firefighter population, the cost of ICA-confirmed diagnosis of CAD is substantially lower with MDCT as gatekeeper than with MPI.