DENVER—With the “explosive growth” of cardiovascular imaging, the focus must now center on improving quality and reducing radiation exposure, and appropriate use criteria (AUC) can help, Robert C. Hendel, MD, director of cardiac imaging and outpatient services at the University of Miami Miller School of Medicine in Miami, said during a presentation Sept. 10 at the 16th annual American Society of Nuclear Cardiology (ASNC) scientific sessions.
The best tactic to help eliminate radiation dose is to eliminate inappropriate testing. “There is no radiation dose for tests not performed,” Hendel said. “Eliminating inappropriate imaging is the critical issue in radiation safety.”
Previous studies have highlighted that there is a substantial regional variation of imaging studies throughout the U.S. “However, the true nature of utilization remains unknown,” Hendel said. It is therefore difficult to determine when imaging studies are being overused, underused and used appropriately.
Hendel offered that “serial testing” is important to watch out for because patients who undergo a series of cardiovascular imaging tests are exposed to even larger doses of radiation. Therefore, the major focus must be on the appropriate use of cardiac imaging, he said.
Practicing physicians must look at algorithms to depict whether or not imaging is appropriate in each individual patient situation. For example, if a patient has a normal scan result and is also at a low risk for coronary heart disease, an additional imaging test would be inappropriate.
“How often do we perform inappropriate testing?” Hendel asked. Some previous studies, like the one Hendel et al performed in 2006, showed that inappropriate use of radionuclide imaging hovers around 11 percent, but could be as high as 24 percent (Carryer et al 2010).
“Are we doing too much testing?” Hendel asked. He noted that a previous study showed that use of SPECT myocardial perfusion imaging (MPI) was 39 percent after patients had a revascularization; however, in reality, only 18 percent of these patients had angina. In this instance, Hendel said that SPECT MPI after revascularization may be performed too much and too soon.
How does AUC impact cardiac imaging?
The AUC, issued by the American College of Cardiology Foundation (ACCF), aims to improve imaging utilization and procedures. “These criteria have established a partnership among clinicians, educators and payors regarding costs and fair reimbursements for these types of exams,” Hendel offered. Additionally, he said the criteria put a larger emphasis on the clinical indications that drive testing.
Additionally, AUC has helped to improve the cost-effectiveness of cardiac imaging as well as reduce unnecessary radiation exposure.
Currently, the average inappropriate rates prior to intervention are between 10 and 15 percent. However, use of tools and education for clinicians on AUC can reduce this number by 50 percent or more, Hendel offered.
He added that a multifaceted approach to education that includes peer discussions and case studies can help reduce the number of inappropriate testing even further. Also, programs like 'Imaging in FOCUS' will help increase appropriate use. In fact, the goal of FOCUS, which was initiated by the American College of Cardiology, is to reduce unnecessary or inappropriate imaging by 15 percent during the first year and 50 percent within the three following years.
“We as clinicians must take responsibility for all aspects of cardiac imaging including utilization and radiation,” Hendel said. “However, the emphasis must be on quality.”
Programs like FOCUS, along with other guidance documents, will be helpful to reach appropriate use and reduce radiation exposure.