Computed tomography myocardial perfusion vs 15O-water positron emission tomography and fractional flow reserve

Computed tomography (CT) can perform comprehensive cardiac imaging. We compared CT coronary angiography (CTCA) and CT myocardial perfusion (CTP) with O-15-water positron emission tomography (PET) and invasive coronary angiography (ICA) with fractional flow reserve (FFR). 51 patients (63 (61-65) years, 80 % male) with known/suspected coronary artery disease (CAD) underwent 320-multidetector CTCA followed by "snapshot" adenosine stress CTP. Of these 22 underwent PET and 47 ICA/FFR. Obstructive CAD was defined as CTCA stenosis > 50 % and CTP hypoperfusion, ICA stenosis > 70 % or FFR < 0.80. PET hyperaemic myocardial blood flow (MBF) was lower in obstructive than non-obstructive territories defined by ICA/FFR (1.76 (1.32-2.20) vs 3.11 (2.44-3.79) mL/(g/min), P < 0.001) and CTCA/CTP (1.76 (1.32-2.20) vs 3.12 (2.44-3.79) mL/(g/min), P < 0.001). Baseline and hyperaemic CT attenuation density was lower in obstructive than non-obstructive territories (73 (71-76) vs 86 (84-88) HU, P < 0.001 and 101 (96-106) vs 111 (107-114) HU, P 0.001). PET hyperaemic MBF corrected for rate pressure product correlated with CT attenuation density (r = 0.579, P < 0.001). There was excellent per-patient sensitivity (96 %), specificity (85 %), negative predictive value (90 %) and positive predictive value (94 %) for CTCA/CTP vs ICA/FFR. CT myocardial attenuation density correlates with O-15-water PET MBF. CTCA and CTP can accurately identify obstructive CAD. CT myocardial perfusion can aid the assessment of suspected coronary artery disease. CT attenuation density from "snapshot" imaging is a marker of myocardial perfusion. CT myocardial attenuation density correlates with (15) O-water PET myocardial blood flow. CT attenuation density is lower in obstructive territories defined by invasive angiography. Diagnostic accuracy of CTCA+CTP is comparable to invasive angiography + fractional flow reserve.