Ethan J. Halpern MD, Abstract Co-Author: Research grant, Koninklijke Philips Electronics NV Research grant, Lantheus Medical Imaging, Inc Equipment support, Toshiba Corporation

Michael Savage MD, Abstract Co-Author: Nothing to Disclose

David Fischman, Abstract Co-Author: Nothing to Disclose

David C. Levin MD, Presenter: Consultant, HealthHelp Board of Directors, Outpatient Imaging Affiliates, LLC

There have been substantial changes in CPT coding and reimbursement for stress testing and coronary CT angiography (cCTA) in the 2010 Medicare fee schedule. We employed a decision analytic model to evaluate diagnostic accuracy and imaging costs for the diagnosis of coronary artery disease (CAD), and to evaluate how changes in the fee schedule might impact the cost-effectiveness of different work-up strategies.

Our decision model utilizes stress testing (stress ECG, stress Echo, or stress myocardial perfusion scintigraphy (MPS)) and cCTA for evaluation of suspected CAD.  All possible combinations of stress tests and cCTA were evaluated. Patients with a positive stress/cCTA evaluation undergo cardiac catheterization. Values of sensitivity and specificity for stress tests and cCTA from the published literature were entered into a decision tree. Costs were evaluated as a function of CAD prevalence based upon the 2009 and 2010 physician Medicare fee schedules.

False positive rate (FPR) is inversely related to CAD prevalence while false negative rate (FNR) is proportional to CAD prevalence. FNR is lowest when cCTA is used as an isolated test. The combination of cCTA with any stress study results in a decreased FPR relative to a stress study alone. FPR is minimized when cCTA is combined with stress echocardiography. Although the cost of MPS was reduced substantially in the 2010 Medicare fee schedule, evaluation with stress MPS alone continues to represent the most expensive diagnostic option for evaluation of CAD. A stress test followed by cCTA results in lower imaging costs as compared to stress testing alone for any disease prevalence below 60-70% (based on the 2010 schedule). Imaging costs are minimized by a strategy that employs stress ECG followed by cCTA. A strategy that employs stress echocardiography followed by cCTA is relatively inexpensive when the prevalence of CAD is below 30%.

Although the absolute costs of stress tests and cCTA have been reduced by varying amounts in the 2010 Medicare fee schedule, work-up strategies that begin with stress ECG or stress Echo and progress to cCTA (if the stress test is positive) continue to represent the least expensive options.

A work-up strategy for CAD that employs stress echocardiography followed by cCTA minimizes FPR with relatively low imaging costs that have been further reduced in the 2010 Medicare fee schedule.

Halpern, E, Savage, M, Fischman, D, Levin, D, Decision Analytic Model for Evaluation of Coronary Artery Disease with Stress ECG, Stress Echocardiography, Radionuclide Stress Perfusion Imaging, and CT Angiography: Impact of Coding and Reimbursement Changes in the 2010 Medicare Fee Schedule.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9001343.html