title: Coronary atheroma composition and its association with segmental endothelial dysfunction in non-ST segment elevation myocardial infarction: novel insights with radiofrequency (iMAP) intravascular ultrasonography.
abstract: Little is known of the relationship between coronary atheroma composition and corresponding endothelial dysfunction. We tested the hypothesis that segmental epicardial vasoreactivity relates to atheroma composition in patients with non-ST segment elevation myocardial infarction (NSTEMI) in vivo. In 23 NSTEMI patients referred for coronary angiography, a non-culprit vessel underwent intracoronary salbutamol (0.30 μg/min) provocation during automated IVUS pullback. A 40 MHz rotational IVUS catheter delivered radiofrequency signals at constant 67 μm intervals via a custom-built IVUS console (iMAP, iLAB, Boston Scientific). Macrovascular response [change in segmental lumen volume (SLV) at baseline and following salbutamol], percent atheroma volume (PAV) and tissue composition was evaluated in 187 contiguous non-overlapping 5 mm coronary segments. Compared with segments that dilated, constrictive segments showed similar SLV, but greater vessel volumes and PAV at baseline. The extent of necrotic and lipidic plaque was significantly greater in constrictive segments, whereas fibrotic plaque content was significantly greater in segments that dilated. Calcific plaque content did not relate to endothelium-dependent vasoreactivity. The change in SLV correlated inversely with the amount of lipidic and necrotic plaque (both r = -0.23, p = 0.002), and directly with fibrotic plaque content (r = 0.23, p = 0.002). In a multivariable model, the extent of both lipidic and necrotic plaque independently associated with segmental vasoconstriction (β = 1.2, p = 0.023; β = 0.66, p = 0.027). Following NSTEMI, both lipidic and necrotic plaque content each associate with segmental endothelial dysfunction. The link between plaque composition and vessel reactivity provides a mechanistic basis of the pathogenesis associated with vulnerable plaque in humans in vivo.
authors.affiliation: Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia.
authors.forename: Rishi
authors.initials: R
authors.lastname: Puri
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Nicholls
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Brennan
authors.forename: Jordan
authors.initials: J
authors.lastname: Andrews
authors.forename: Gary Y
authors.initials: GY
authors.lastname: Liew
authors.forename: Angelo
authors.initials: A
authors.lastname: Carbone
authors.forename: Barbara
authors.initials: B
authors.lastname: Copus
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Nelson
authors.forename: Samir R
authors.initials: SR
authors.lastname: Kapadia
authors.forename: E Murat
authors.initials: EM
authors.lastname: Tuzcu
authors.forename: John F
authors.initials: JF
authors.lastname: Beltrame
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Worthley
authors.forename: Matthew I
authors.initials: MI
authors.lastname: Worthley
mesh_terms: D058666:Adrenergic beta-2 Receptor Agonists; D000368:Aged; D000420:Albuterol; D062906:Cardiac Catheters; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D003331:Coronary Vessels / Q000737:chemistry / Q000000981:diagnostic imaging / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000737:chemistry / Q000000981:diagnostic imaging / Q000503:physiopathology; D004867:Equipment Design; D005260:Female; D005355:Fibrosis; D006801:Humans; D008055:Lipids / Q000032:analysis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D009336:Necrosis; D058226:Plaque, Atherosclerotic; D011237:Predictive Value of Tests; D018084:Ultrasonography, Interventional / Q000295:instrumentation / Q000379:methods*; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000503:physiopathology; D014661:Vasoconstriction
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D008055:Lipids; D000420:Albuterol