Myocardial perfusion imaging dominates coronary CT in EDs

Despite an increase of coronary CT angiography (CCTA) exams in emergency departments (EDs) in the last decade, myocardial perfusion imaging (MPI) examinations and stress echocardiography remain the dominant imaging exams for patients with acute chest pain, according to a study published online on Feb. 15 in the American Journal of Roentgenology.

Researchers from Thomas Jefferson University Hospital in Philadelphia and HealthHelp in Houston compared the frequency of CCTA with MPI and stress echocardiography exams in the ED on Medicare patients with chest pain. Image testing such as CCTA and MPI is required for patients with chest pain when electrocardiography and cardiac enzyme determination are not enough to determine a diagnosis.  

"In view of the findings of the three aforementioned ED trials [MPI, stress echocardiography and coronary CT angiography], our purpose was to specifically focus on trends in the use of CCTA in EDs for patients presenting with chest pain and to compare the use of CCTA with trends in the use of older procedures such as MPI and stress echocardiography," said lead author David Levin, MD, a consultant to HealthHelp and a member of the board of directors of Outpatient Imaging Affiliates and colleagues.   

Data for the study were from nationwide Medicare Part B databases from 2006 to 2015. Medicare specialty codes were used to determine how many of the exams were interpreted by either radiologist, cardiologists or other physician groups.  

Researchers found the MPI or stress echocardiograms exams performed in EDs remained relatively stagnant, with MPIs remaining around 22,340 and stress echocardiograms around 3,530. The number of CCTA exams increased from 2006 to 2015. However, these were less than MPI or stress echocardiography exams (from 126 in 2006 to 1,919 in 2015), according to study results.

"Despite this rapid growth, patients in EDs underwent 11.6 times as many MPI as CCTA examinations in 2015, the authors wrote. "In that last year of the study, radiologists interpreted 78 percent of ED MPI and 83 percent of ED CCTA examinations."  

Due to the number of MPI exams performed exceeding the number CCTA exams performed in ED settings for patients with acute chest pain, researchers believe that appropriateness criteria for chest pain alluding to acute coronary syndrome should be "revised to rate CCTA higher than both MPI and stress echocardiography."