Ines Valenta1, Alessandra Quercioli2, Thomas H Schindler3. 1. Division of Nuclear Medicine, Department of Radiology, and Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, Maryland. 2. Department of Specialties in Medicine, University Hospitals of Geneva, Geneva, Switzerland. 3. Division of Nuclear Medicine, Department of Radiology, and Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, Maryland. Electronic address: Thomas.h.schindler@gmail.com.
Abstract
OBJECTIVES: The purpose of this study was to evaluate the diagnostic value of a positron emission tomography (PET)/computed tomography (CT)-determined longitudinal decrease in myocardial blood flow (MBF) gradient during hyperemia and myocardial flow reserve (MFR) for the identification of epicardial stenosis ≥50%. BACKGROUND: Although PET-determined reductions in MFR are increasingly applied to identify epicardial lesions in coronary artery disease (CAD), it may be seen as a suboptimal approach due to the nonspecific origin of decreases in MFR. METHODS: In 24 patients with suspected or known CAD, MBF was measured with (13)N-ammonia and PET/CT in ml/g/min at rest, during dipyridamole stimulation, and the corresponding MFR was calculated. MBF was also determined in the mid and mid-distal myocardium of the left ventricle (LV). A decrease in MBF from mid to mid-distal LV myocardium was defined as longitudinal MBF gradient. MBF parameters were determined in the myocardial region with stress-induced perfusion defect and with stenosis ≥50% (territory 1), without defect but with stenosis ≥50% (territory 2), or without stenosis ≥50% (territory 3). RESULTS: In territories 1 and 2 with focal stenosis ≥50%, the severity of epicardial artery stenosis correlated with the Δlongitudinal MBF gradient (stress-rest) (r = 0.52; p < 0.0001), while this association was less pronounced for corresponding MFR (r = -0.40; p < 0.003). On a vessel-based analysis, the sensitivity and specificity of the Δlongitudinal MBF gradient in the identification of epicardial lesions was higher than those for MFR (88% vs. 71%, p ≤ 0.044; and 81% vs. 63%, p = 0.134, respectively). Combining both parameters resulted in an optimal sensitivity of 100% and intermediate specificity of 75%. The diagnostic accuracy was highest for the combined analysis than for the Δlongitudinal MBF gradient or MFR alone (94% vs. 86%, p ≤ 0.003; and 94% vs. 70%, p ≤ 0.0002). CONCLUSIONS: The combined evaluation of a Δlongitudinal MBF gradient and MFR may evolve as a new promising analytic approach to further optimize the identification of CAD lesions.
OBJECTIVES: The purpose of this study was to evaluate the diagnostic value of a positron emission tomography (PET)/computed tomography (CT)-determined longitudinal decrease in myocardial blood flow (MBF) gradient during hyperemia and myocardial flow reserve (MFR) for the identification of epicardial stenosis ≥50%. BACKGROUND: Although PET-determined reductions in MFR are increasingly applied to identify epicardial lesions in coronary artery disease (CAD), it may be seen as a suboptimal approach due to the nonspecific origin of decreases in MFR. METHODS: In 24 patients with suspected or known CAD, MBF was measured with (13)N-ammonia and PET/CT in ml/g/min at rest, during dipyridamole stimulation, and the corresponding MFR was calculated. MBF was also determined in the mid and mid-distal myocardium of the left ventricle (LV). A decrease in MBF from mid to mid-distal LV myocardium was defined as longitudinal MBF gradient. MBF parameters were determined in the myocardial region with stress-induced perfusion defect and with stenosis ≥50% (territory 1), without defect but with stenosis ≥50% (territory 2), or without stenosis ≥50% (territory 3). RESULTS: In territories 1 and 2 with focal stenosis ≥50%, the severity of epicardial artery stenosis correlated with the Δlongitudinal MBF gradient (stress-rest) (r = 0.52; p < 0.0001), while this association was less pronounced for corresponding MFR (r = -0.40; p < 0.003). On a vessel-based analysis, the sensitivity and specificity of the Δlongitudinal MBF gradient in the identification of epicardial lesions was higher than those for MFR (88% vs. 71%, p ≤ 0.044; and 81% vs. 63%, p = 0.134, respectively). Combining both parameters resulted in an optimal sensitivity of 100% and intermediate specificity of 75%. The diagnostic accuracy was highest for the combined analysis than for the Δlongitudinal MBF gradient or MFR alone (94% vs. 86%, p ≤ 0.003; and 94% vs. 70%, p ≤ 0.0002). CONCLUSIONS: The combined evaluation of a Δlongitudinal MBF gradient and MFR may evolve as a new promising analytic approach to further optimize the identification of CAD lesions.
Authors: Ami E Iskandrian; Vasken Dilsizian; Ernest V Garcia; Rob S Beanlands; Manuel Cerqueira; Prem Soman; Daniel S Berman; Alberto Cuocolo; Andrew J Einstein; Charity J Morgan; Fadi G Hage; Heinrich R Schelbert; Jeroen J Bax; Joseph C Wu; Leslee J Shaw; Mehran M Sadeghi; Nagara Tamaki; Philipp A Kaufmann; Robert Gropler; Sharmila Dorbala; William Van Decker Journal: J Nucl Cardiol Date: 2017-11-06 Impact factor: 5.952
Authors: Ines Valenta; Alexander Antoniou; Wael Marashdeh; Thorsten Leucker; Edward Kasper; Steven R Jones; Robert F Dannals; Lilja Solnes; Martin G Pomper; Thomas H Schindler Journal: Eur Heart J Cardiovasc Imaging Date: 2017-05-01 Impact factor: 6.875