title: Carotid artery intima-media thickness, but not coronary artery calcium, predicts coronary vascular resistance in patients evaluated for coronary artery disease.
abstract: OBJECTIVE
  There is growing evidence that coronary artery disease (CAD) affects not only the conduit epicardial coronary arteries, but also the microvascular coronary bed. Moreover, coronary microvascular dysfunction (CMVD) often precedes the stage of clinically overt epicardial CAD. Coronary artery calcium (CAC) and carotid intima-media thickness (C-IMT) measured with computed tomography (CT) and ultrasound, respectively, are among the available techniques to non-invasively assess atherosclerotic burden. An increased CAC score and C-IMT have also been associated with CMVD. It is therefore of interest to explore and compare the potential of CAC against C-IMT to predict minimal coronary vascular resistance (CVR).
  
  
  RESULTS
  We evaluated 120 patients (mean age 56 ± 9 years, 58 men) without a documented history of CAD in whom obstructive CAD was excluded. All patients underwent C-IMT measurements, CAC scoring, and vasodilator stress (15)O-water positron emission tomography (PET)/CT, during which the coronary flow reserve (CFR) and minimal CVR were analysed. Minimal CVR increased significantly with increasing tertiles of C-IMT (22 ± 6, 27 ± 11, and 28 ± 9 mmHg mL(-1)min(-1) g(-1), P < 0.01), whereas the CFR was comparable across all C-IMT groups (P = 0.50). Minimal CVR increased significantly with an increase in CAC score (23 ± 9, 27 ± 8, 32 ± 10, and 32 ± 7 mmHg mL(-1) min(-1) g(-1), P < 0.01), whereas the CFR did not show a significant decrease with higher CAC scores (P = 0.18). Multivariable regression analysis revealed that C-IMT (P = 0.03), but not CAC, was independently associated with minimal CVR.
  
  
  CONCLUSIONS
  C-IMT, but not CAC score, independently predicts minimal CVR in patients with multiple cardiovascular risk factors and suspected of CAD.
authors.affiliation: Department of Cardiology, VU University Medical Center, De Boelelaan 1117, Amsterdam, The Netherlands. i.danad@vumc.nl
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Danad
authors.forename: Pieter G
authors.initials: PG
authors.lastname: Raijmakers
authors.forename: Parisa
authors.initials: P
authors.lastname: Kamali
authors.forename: Hendrik J
authors.initials: HJ
authors.lastname: Harms
authors.forename: Stefan
authors.initials: S
authors.lastname: de Haan
authors.forename: Mark
authors.initials: M
authors.lastname: Lubberink
authors.forename: Cornelis
authors.initials: C
authors.lastname: van Kuijk
authors.forename: Otto S
authors.initials: OS
authors.lastname: Hoekstra
authors.forename: Adriaan A
authors.initials: AA
authors.lastname: Lammertsma
authors.forename: Yvo M
authors.initials: YM
authors.lastname: Smulders
authors.forename: Martijn W
authors.initials: MW
authors.lastname: Heymans
authors.forename: Igor I
authors.initials: II
authors.lastname: Tulevski
authors.forename: Albert C
authors.initials: AC
authors.lastname: van Rossum
authors.forename: Paul
authors.initials: P
authors.lastname: Knaapen
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000473:pathology*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000473:pathology*; D003326:Coronary Circulation; D005260:Female; D006305:Health Status Indicators; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011379:Prognosis; D018570:Risk Assessment; D013223:Statistics as Topic; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000473:pathology*; D017540:Tunica Media / Q000000981:diagnostic imaging / Q000473:pathology*; D014463:Ultrasonography; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000473:pathology*; D014655:Vascular Resistance