PET Imaging Detects Coronary Artery Disease at Early Stage

June 10, 2013—At the Society for Nuclear Medicine and Molecular Imaging's 2013 annual meeting, held from June 8–12 in Vancouver, Canada, researchers presented a study comparing two forms of positron emission tomography (PET) in patients suspected to have coronary artery disease (CAD), concluding that a technique using PET can detect earlier stages of disease.

Forty-five patients (mean age, 51 y) who were suspected to have CAD but had no history of heart attack were prescribed dietary restrictions and on separate days, underwent two molecular imaging methods: exercise stress myocardial perfusion imaging (MPI) and exercise stress cardiac PET imaging with injected F-18 fluorodeoxyglucose (FDG). Angiography was performed within 1 month.

Twenty-seven patients had abnormal angiograms, with at least one artery narrowed by more than 50%. Disease staging was organized into single-, double-, and triple-vessel disease. Comparison between imaging methods showed that 17 patients had single-vessel disease and were better imaged by FDG PET imaging than by MPI. Five patients had double-vessel disease and five had triple-vessel disease. MPI and FDG PET were similar for multivessel disease detection but FDG PET was found to be superior for single-vessel disease. PET was shown to have 96% sensitivity while detecting < 50% stenosis of coronary arteries, while MPI had approximately 56% sensitivity. Specificity, the method's accuracy when detecting CAD at this level, was measured at 76% for FDG PET and 62% for MPI, proving that FDG PET catches earlier stages of disease, the society's press release stated.

“Using FDG PET, we can easily detect changes that occur in the heart at the microscopic level—much sooner than when changes become evident in angiography, at the macroscopic level,” said Arun Sasikumar, MD, MBBS, in the society's press release. Dr. Sasikumar is Lead Researcher from the Department of Nuclear Medicine at the Post Graduate Institute of Medical Education and Research based in Chandigarh, India. “By detecting the detrimental changes in the heart at an early stage, physicians can prescribe medications that can halt disease progression, thus preventing a devastating cardiac event such as heart attack or sudden cardiac death.”