PET imaging can detect severe obstructive coronary artery disease (CAD) better than SPECT imaging, according to a new study conducted by Intermountain Medical Center Heart Institute.

"Since Intermountain Medical Center made the switch from SPECT to PET in 2013, we thought it would be valuable to look at the differences in clinical outcomes since then," Dr. Kirk Knowlton, director of cardiovascular research, said in a statement.

Data from the National Institutes of Health shows that CAD is the most common type of heart disease and is also the leading cause of death in the U.S. for both men and women.
For the study, Knowlton and his team identified 3,394 patients who underwent pharmacologic SPECT exams from 2011 to 2012 and 7,478 patients who underwent PET exams from 2014 to 2015 at Intermountain. They then conducted a retrospective analysis of catheterization outcomes 60 days after the patients received various treatments.

The team found that PET scans diagnosed 79 percent of severe obstructive CAD cases and SPECT scans diagnosed 70 percent. In addition, PET scans were associated with a 12 percent lower incidence of invasive catheterization without identification of severe CAD.

The researchers concluded that PET was more successful than SPECT at identifying patients with severe obstructive CAD, and which patients required revascularization. PET also increased true positive and reduced false positive diagnoses.

“This has broad implications as physicians consider what test best serves their individual patients, and institutions consider the advantages and disadvantages of SPECT and PET as well as downstream resource utilization,” said Dr. David Min, cardiologist and lead author of the study.

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