title: Transmural myocardial perfusion gradients in relation to coronary artery stenoses severity assessed by cardiac multidetector computed tomography.
abstract: To assess the relationship between epicardial coronary artery stenosis severity and the corresponding regional transmural perfusion at rest and during adenosine stress, using multidetector computed tomography (MDCT). We evaluated the relationship between the severity of coronary artery diameter stenosis assessed by MDCT angiography and semi-quantitative myocardial MDCT perfusion in 200 symptomatic patients. The perfusion index (PI = mean myocardial attenuation density/mean left ventricular lumen attenuation density) at rest and during adenosine stress, the myocardial perfusion reserve (MPR = stress - PI/rest - PI), and the transmural perfusion ratio (TPR = subendocardium/subepicardium) were calculated. A coronary artery stenosis ≥50 % was present in 49 patients (25 %). Rest-PI and rest-TPR values were similar in patients with and without a coronary artery stenosis ≥50 %, whereas stress-PI, stress-TPR and MPR were significantly reduced in patients with a stenosis ≥50 % (p < 0.001, p < 0.0001 and p = 0.02, respectively). Subendocardial PI was significantly higher than subepicardial PI at rest and during stress for patients without a significant stenosis, whereas this difference was blurred during stress in patients with ≥50 % stenosis. In a broad spectrum of stenosis severity groups, TPR at rest remained unchanged until the group of patients with total occlusions, whereas TPR during stress decreased progressively when a threshold of 50 % was superseded. In this study we establish the relationship between semi-quantitative perfusion measurements by MDCT and severity of coronary artery stenoses and find the transmural myocardial perfusion ratio to be a potential strong functional index of the hemodynamic significance of coronary artery atherosclerotic lesions.
authors.affiliation: Department of Cardiology, Hvidovre Hospital, University of Copenhagen, Kettegård alle 30, 2650, Hvidovre, Denmark, jesper_linde@hotmail.com.
authors.forename: Jesper James
authors.initials: JJ
authors.lastname: Linde
authors.forename: Jørgen Tobias
authors.initials: JT
authors.lastname: Kühl
authors.forename: Jens Dahlgaard
authors.initials: JD
authors.lastname: Hove
authors.forename: Mathias
authors.initials: M
authors.lastname: Sørgaard
authors.forename: Henning
authors.initials: H
authors.lastname: Kelbæk
authors.forename: Walter Bjørn
authors.initials: WB
authors.lastname: Nielsen
authors.forename: Klaus Fuglsang
authors.initials: KF
authors.lastname: Kofoed
mesh_terms: D000241:Adenosine; D000328:Adult; D000368:Aged; D003326:Coronary Circulation; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003718:Denmark; D005260:Female; D006439:Hemodynamics; D006801:Humans; D006940:Hyperemia / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D015588:Observer Variation; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014665:Vasodilator Agents
chemical_list: D014665:Vasodilator Agents; D000241:Adenosine