Authors: Ibrahim Danad Pieter G Raijmakers Yolande E Appelman Hendrik J Harms Stefan de Haan Mijntje L P van den Oever Cornelis van Kuijk Cornelis P Allaart Otto S Hoekstra Adriaan A Lammertsma Mark Lubberink Albert C van Rossum Paul Knaapen
Publish Date: 2011/10/18
Volume: 39, Issue: 1, Pages: 102-112
Abstract
There has been increasing interest in quantitative myocardial blood flow MBF imaging over the last years and it is expected to become a routinely used technique in clinical practice Positron emission tomography PET using 15OH2O is the established gold standard for quantification of MBF in vivo A fundamental issue when performing quantitative MBF imaging is to define the limits of MBF in a clinically suitable population The aims of the present study were to determine the limits of MBF and to determine the relationship among coronary artery disease CAD risk factors gender and MBF in a predominantly symptomatic patient cohort without significant CADA total of 128 patients mean age 54 ± 10 years 50 men with a low to intermediate pretest likelihood of CAD were referred for noninvasive evaluation of CAD using a hybrid PET/computed tomography PET/CT scanner MBF was quantified with 15OH2O at rest and during adenosineinduced hyperaemia Obstructive CAD was excluded in these patients by means of invasive or CTbased coronary angiographyGlobal average baseline MBF values were 091 ± 034 and 109 ± 030 ml·min−1·g−1 range 054–235 and 059–275 ml·min−1·g−1 in men and women respectively p 001 However no genderdependent difference in baseline MBF was seen following correction for rate–pressure product 098 ± 045 and 109 ± 030 ml·min−1·g−1 in men and women respectively p = 008 Global average hyperaemic MBF values were 344 ± 120 ml·min−1·g−1 in the whole study population and 290 ± 085 and 378 ± 127 ml·min−1·g−1 range 152–522 and 172–815 ml·min−1·g−1 in men and women respectively p 0001 Multivariate analysis identified male gender age and body mass index as having an independently negative impact on hyperaemic MBFThere has been increasing interest in quantitative myocardial perfusion imaging over the last years and it is expected to become routinely implemented in clinical practice 1 2 3 Myocardial blood flow MBF measurements add incremental value to the diagnosis and evaluation of coronary artery disease CAD compared with qualitative perfusion imaging techniques 1 4 5 Furthermore quantitative MBF values can be used to evaluate the effect of lifestyle changes and pharmacological interventions in patients with CAD risk factors and impaired MBF Positron emission tomography PET is the established gold standard for quantitative MBF imaging 1 3 4 6 A number of PET tracers eg 13NNH3 82Rb and 15OH2O are currently available and are well validated 7 8 9 10 Nonetheless the number of studies that have routinely evaluated the use of quantitative MBF values in the diagnosis of CAD are scarce 5 11 One of the fundamental issues when performing quantitative MBF imaging is to define lower limits of hyperaemic MBF Although databases are available with normal MBF values these data were predominantly obtained in healthy volunteers in whom CAD had not been excluded 12 13 14 Furthermore the limits of MBF values obtained from these studies are of less clinical value taking into consideration that these studies were performed in asymptomatic individuals without multiple risk factors for CAD which are known to affect MBF even in the absence of epicardial atherosclerosis 15Therefore the aims of this study were to determine the limits of MBF and to investigate the impact of age gender and CAD risk factors on MBF using 15OH2O PET in a large clinical cohort of patients suspected of having and with risk factors for CAD but in whom significant CAD was excluded by invasive coronary angiography ICA or CTbased coronary angiography CTCA
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