PET myocardial blood flow finds under-diagnosed multivessel CAD
Evaluating myocardial blood flow (MBF) with stress-rest cardiac PET teases out more multivessel CAD than with cardiac PET or SPECT alone, both of which tend to underestimate severity of disease, according the proceedings of the 2013 American Society of Nuclear Cardiology (ASNC) 2013 Annual Meeting held Sept. 26-29 in Chicago.
Junyang Lou, MD, a cardiologist at Cleveland Clinic, and colleagues conducted a retrospective study of 190 patients at the institution who underwent Rubidium-82 cardiac rest and Regadenoson stress cardiac PET from December 2010 to March 2013. Researchers analyzed the data and calculated MBF to determine additional multivessel disease.
“Even using PET technology, the frequency of underestimation of anatomic CAD and the presence of balanced reduction is not insignificant,” wrote Lou et al. “The use of MBF as an adjunct to perfusion was able to correctly identify the majority of these ‘missed’ cases.”
Results of the study showed that while cardiac PET demonstrated 90 percent sensitivity, CAD was under-diagnosed in 50 percent of cases. A total of 56 percent of patients had three-vessel CAD, 26 percent had two-vessel CAD and 27 percent had one-vessel CAD. A total of 34 patients were found to have no obstructive CAD.
These results were compared to angiographic findings and out of 23 patients with normal perfusion results, 53 percent showed some CAD via angiography. However 61 percent of these patients’ CAD was caught with additional MBF assessment.
For those patients who were originally found to have one-vessel CAD by MPI, 47 percent of patients (40 out of 86) had multi-vessel disease according to angiography. MBF picked up additional CAD in 31 of these 40 patients. Likewise, 45 percent of the 29 patients originally thought to have two-vessel CAD by MPI showed more extensive disease with angiography. MBF was able to identify more abnormalities in 69 percent of these cases.
According to these results, the addition of MBF values when assessing MPI data could potentially improve the diagnostic accuracy of stress-rest cardiac PET for the detection of multivessel CAD.