Diagnostic accuracy of N-ammonia myocardial perfusion imaging with PET-CT in the detection of coronary artery disease.

Background: N-ammonia positron emission tomography-computed tomography (PET-CT) is being increasingly used as a non-invasive imaging modality for evaluating patients with known or suspected coronary artery disease (CAD), but information about the diagnostic accuracy of PET-MPI is sparse. Objectives: Our objective was to determine the accuracy of N-ammonia PET-CT myocardial perfusion imaging (MPI) for detecting CAD.

Methods: We retrospectively evaluated 383 patients with suspected CAD who underwent rest-stress N- ammonia PET-CT MPI. Invasive coronary angiography (ICA) was performed within 60 days for all patients with abnormal PET-MPI findings and for selected patients with normal PET-MPI findings.

Results: The mean age of the patients was 64±11 years, and the mean body mass index was 32±7 kg/m. Stress perfusion defects were identified in 147 (34%) out of a total of 383 patients. ICA was performed in 213 patients (145 patients with abnormal PET and 68 patients with normal PET). The sensitivity of PET-MPI for detection of obstructive CAD based on ≥50% stenosis was 90%; specificity, 90%; positive predictive value, 96%; negative predictive value, 76%; and diagnostic accuracy, 80%.

Conclusions: PET-MPI with N-ammonia affords high sensitivity and overall accuracy for detecting CAD. The addition of coronary artery calcium score (CACS) can improve CAD risk stratification.