FLURPIRIDAZ F 18 PET VERSUS TC-99M SPECT FOR MYOCARDIAL PERFUSION IMAGING
Daniel S. Berman, M.D., Cedars-Sinai Medical Center, Los Angeles, CA, USA
Flurpiridaz F-18, a new PET tracer for myocardial perfusion imaging has recently been studied in a Phase II trial. In pre-clinical and phase-I studies, flurpiridaz F-18 has shown essentially linear myocardial uptake throughout the range of flow. It does not require an on-site cyclotron. Unlike rubidium-82, flurpiridaz F-18 is retained in the myocardium and can be used with exercise. Various characteristics suggest flurpiridaz F-18 might an ideal myocardial perfusion tracer. In the Phase II clinical trial (Berman, et al: JACC 2013), we studied 143 patients with rest-stress PET and Tc-99m SPECT MPI. A higher percentage of PET images were rated as excellent/good at stress (99.2% vs. 88.5%, p < 0.01) and rest (96.9% vs. 66.4, p< 0.01). Diagnostic certainty (percentage definitely abnormal/normal) was higher for PET (90.8% vs. 70.9%, p<0.01). In 86 patients who underwent ICA, PET sensitivity was higher (78.8% vs. 61.5%, respectively, p=0.02). Specificity was not significantly different (PET: 76.5% vs. SPECT: 73.5%). Receiver-operating characteristic curve area was 0.82± 0.05 for PET and 0.70± 0.06 for SPECT (p=0.04). Normalcy rate was 89.7% with PET and 97.4% with SPECT (p=NS). In patients with CAD, reversible defect magnitude was greater with PET than SPECT (p=0.008). Thus, PET MPI with flurpiridaz F-18 was superior to SPECT MPI for image quality, interpretative, certainty, and overall CAD diagnosis. This new tracer might significantly improve the assessment of patients with radionuclide MPI compared with the standard SPECT MPI methods and could provide a major advance in noninvasive assessment of CAD.