Integrated Myocardial Perfusion Imaging Diagnostics Improve Detection of Functionally Significant Coronary Artery Stenosis by 13 N-ammonia Positron Emission Tomography

Abstract

Background—: Recent evidence suggests that the diagnostic accuracy of myocardial perfusion imaging is improved by quantifying stress myocardial blood flow (MBF) in absolute terms. We evaluated a comprehensive quantitative ¹³ N-ammonia positron emission tomography ( ¹³ NH ₃ -PET) diagnostic panel, including stress MBF, coronary flow reserve (CFR), and relative flow reserve (RFR) in conjunction with relative perfusion defect (PD) assessments to better detect functionally significant coronary artery stenosis. Methods and Results—: A total of 130 patients (307 vessels) with coronary artery disease underwent both ¹³ NH ₃ -PET and invasive coronary angiography with fractional flow reserve (FFR) measurement. Diagnostic accuracy, optimal cut points, and discrimination indices of respective ¹³ NH ₃ -PET quantitative measures were compared, with FFR as standard reference. The capacity to discern disease with stepwise addition of stress MBF, CFR, and RFR to qualitatively assessed relative PD was also gauged, using the category-free net reclassification index. All quantitative measures showed significant correlation with FFR (PET-derived CFR, r =0.388; stress MBF, r =0.496; and RFR, r =0.780; all P P P 13 NH ₃ -PET measures with qualitative myocardial perfusion assessment provides superior diagnostic accuracy and improves the capacity to detect functionally significant coronary artery stenosis. Clinical Trial Registration—: URL: http://www.clinicaltrials.gov . Unique identifiers: NCT01621438 and NCT01366404.