Cardiac CT (CCT) in the emergency department (ED) is more cost effective in evaluating patients with suspected acute coronary syndrome (ACS) than the standard of care involving multiple tests and a stress SPECT scan, even when the downstream costs of CCT are considered, according to a study published in the March issue of Academic Radiology.

Chest pain accounts for 5 percent of all U.S. ED visits, with approximately $12 billion spent on the evaluation of acute chest pain in 2008. Kelley R. Branch, MD, of the division of cardiology at the University of Washington in Seattle, and colleagues noted that these costs could be reduced if electrocardiogram-gated thoracic CT were used in place of the standard of care (SOC).

To test the cost-effectiveness of CCT, while accounting for downstream costs such as iodinated contrast complications or incidental, noncardiac CT findings, the researchers constructed a decision analytic cost-minimization model. Using data from a cohort study of 102 patients at low to intermediate risk for ACS who underwent an emergency department SOC clinical evaluation and a 64-channel CCT, they compared CCT-based and SOC evaluation costs to obtain a correct diagnosis.

Results showed that CCT-based evaluation of patients was 24 percent less expensive at one year, with mean CCT and SOC costs of $2,384 and $3,134, respectively. There were no expected differences in health outcomes.

“Sensitivity analyses indicated that CCT was less expensive over a wide range of estimates and was only more expensive with a CCT specificity below 67 percent or if more than 44 percent of very low risk patients had CCT,” wrote the authors. “Probabilistic sensitivity analysis suggested that CCT-based evaluation had a 98.9 percent probability of being less expensive compared to SOC.”

SOC costs included stress testing for 77 percent of patients, and the overall savings were largely the result of cost differences between CCT and stress imaging, according to the authors.

“Based on these findings, the most substantial cost savings for CCT evaluation would be in lower-risk patients who would otherwise have a SOC cardiac evaluation that included [ED] observation and stress testing,” wrote Branch et al. “Although the cost savings associated with CCT is reduced with inclusion of populations at higher risk for ACS or downstream expenses from the CT, such as older patients or those with additional cardiac risk factors, our study suggests that CCT is less expensive for the majority of low to intermediate-risk patients.”

The researchers suggested future cost analyses may be warranted, including those from larger populations and from different perspectives. They also suggested that future studies take into account the opportunity cost of decreased time in the ED with CCT evaluation.