title: Non-invasive detection of coronary endothelial response to sequential handgrip exercise in coronary artery disease patients and healthy adults.
abstract: OBJECTIVE
  Our objective is to test the hypothesis that coronary endothelial function (CorEndoFx) does not change with repeated isometric handgrip (IHG) stress in CAD patients or healthy subjects.
  
  
  BACKGROUND
  Coronary responses to endothelial-dependent stressors are important measures of vascular risk that can change in response to environmental stimuli or pharmacologic interventions. The evaluation of the effect of an acute intervention on endothelial response is only valid if the measurement does not change significantly in the short term under normal conditions. Using 3.0 Tesla (T) MRI, we non-invasively compared two coronary artery endothelial function measurements separated by a ten minute interval in healthy subjects and patients with coronary artery disease (CAD).
  
  
  METHODS
  Twenty healthy adult subjects and 12 CAD patients were studied on a commercial 3.0 T whole-body MR imaging system. Coronary cross-sectional area (CSA), peak diastolic coronary flow velocity (PDFV) and blood-flow were quantified before and during continuous IHG stress, an endothelial-dependent stressor. The IHG exercise with imaging was repeated after a 10 minute recovery period.
  
  
  RESULTS
  In healthy adults, coronary artery CSA changes and blood-flow increases did not differ between the first and second stresses (mean % change ±SEM, first vs. second stress CSA: 14.8%±3.3% vs. 17.8%±3.6%, p = 0.24; PDFV: 27.5%±4.9% vs. 24.2%±4.5%, p = 0.54; blood-flow: 44.3%±8.3 vs. 44.8%±8.1, p = 0.84). The coronary vasoreactive responses in the CAD patients also did not differ between the first and second stresses (mean % change ±SEM, first stress vs. second stress: CSA: -6.4%±2.0% vs. -5.0%±2.4%, p = 0.22; PDFV: -4.0%±4.6% vs. -4.2%±5.3%, p = 0.83; blood-flow: -9.7%±5.1% vs. -8.7%±6.3%, p = 0.38).
  
  
  CONCLUSIONS
  MRI measures of CorEndoFx are unchanged during repeated isometric handgrip exercise tests in CAD patients and healthy adults. These findings demonstrate the repeatability of noninvasive 3T MRI assessment of CorEndoFx and support its use in future studies designed to determine the effects of acute interventions on coronary vasoreactivity.
authors.affiliation: Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, Maryland, United States of America.
authors.forename: Allison G
authors.initials: AG
authors.lastname: Hays
authors.forename: Matthias
authors.initials: M
authors.lastname: Stuber
authors.forename: Glenn A
authors.initials: GA
authors.lastname: Hirsch
authors.forename: Jing
authors.initials: J
authors.lastname: Yu
authors.forename: Michael
authors.initials: M
authors.lastname: Schär
authors.forename: Robert G
authors.initials: RG
authors.lastname: Weiss
authors.forename: Gary
authors.initials: G
authors.lastname: Gerstenblith
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kelle
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000503:physiopathology*; D003331:Coronary Vessels / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D018737:Hand Strength; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D012307:Risk Factors; D013312:Stress, Physiological; D014664:Vasodilation; D055815:Young Adult
references.citation: Herz. 1996 Apr;21(2):90-6
references.pmid: 8682442
references.citation: Am J Physiol. 1997 Dec;273(6):H2575-9
references.pmid: 9435589
references.citation: N Engl J Med. 2000 Feb 17;342(7):454-60
references.pmid: 10675425
references.citation: Eur J Nucl Med Mol Imaging. 2009 Feb;36(2):219-29
references.pmid: 18704406
references.citation: Circulation. 2003 Jun 10;107(22):2805-9
references.pmid: 12771004
references.citation: Am Heart J. 2003 Jan;145(1):E3
references.pmid: 12514675
references.citation: Atherosclerosis. 2004 Mar;173(1):115-23
references.pmid: 15177131
references.citation: Am J Cardiol. 2011 Aug 15;108(4):491-7
references.pmid: 21624552
references.citation: Circulation. 2000 Mar 7;101(9):948-54
references.pmid: 10704159
references.citation: Hypertension. 2012 Sep;60(3):827-32
references.pmid: 22851734
references.citation: J Magn Reson Imaging. 2001 Oct;14(4):383-90
references.pmid: 11599062
references.citation: Circulation. 2000 Nov 21;102(21):2582-7
references.pmid: 11085960
references.citation: N Engl J Med. 1986 Oct 23;315(17):1046-51
references.pmid: 3093861
references.citation: Circulation. 2002 Jul 16;106(3):296-9
references.pmid: 12119242
references.citation: Circulation. 2000 Apr 25;101(16):1931-9
references.pmid: 10779459
references.citation: Circulation. 2000 Aug 1;102(5):506-10
references.pmid: 10920061
references.citation: Am J Clin Nutr. 2007 Aug;86(2):334-40
references.pmid: 17684202
references.citation: Circulation. 1992 May;85(5):1899-911
references.pmid: 1572046
references.citation: J Physiol. 2004 Nov 15;561(Pt 1):1-25
references.pmid: 15375191
references.citation: J Am Coll Cardiol. 2001 Jun 1;37(7):1864-70
references.pmid: 11401124
references.citation: J Magn Reson Imaging. 2004 Dec;20(6):953-60
references.pmid: 15558551
references.citation: Circulation. 2000 Apr 25;101(16):1899-906
references.pmid: 10779454
references.citation: N Engl J Med. 1990 Dec 6;323(23):1593-600
references.pmid: 2233948
references.citation: J Am Coll Cardiol. 2010 Nov 9;56(20):1657-65
references.pmid: 21050976
references.citation: J Am Coll Cardiol. 1999 Aug;34(2):524-31
references.pmid: 10440168
references.citation: Circulation. 1996 Apr 15;93(8):1502-8
references.pmid: 8608617
references.citation: J Am Coll Cardiol. 1990 Mar 15;15(4):827-32
references.pmid: 2407762
references.citation: J Card Fail. 1998 Sep;4(3):193-201
references.pmid: 9754590
references.citation: Circ Res. 1994 Feb;74(2):349-53
references.pmid: 7507417
references.citation: Magn Reson Med. 1999 Mar;41(3):544-9
references.pmid: 10204878
references.citation: J Am Coll Cardiol. 2005 Jan 4;45(1):104-10
references.pmid: 15629383
references.citation: Sports Med. 1996 Feb;21(2):119-46
references.pmid: 8775517
references.citation: N Engl J Med. 1995 Feb 23;332(8):481-7
references.pmid: 7830728
references.citation: J Am Coll Cardiol. 2003 Sep 3;42(5):814-22
references.pmid: 12957426
references.citation: Circulation. 1998 Dec 15;98(24):2709-15
references.pmid: 9851957
references.citation: Circulation. 1988 Jan;77(1):43-52
references.pmid: 2826047
references.citation: Circulation. 1993 Jan;87(1):94-104
references.pmid: 8419029
references.citation: Circulation. 1984 Jul;70(1):18-24
references.pmid: 6426817
references.citation: J Appl Physiol (1985). 1994 Oct;77(4):1829-33
references.pmid: 7836206
references.citation: Magn Reson Med. 1992 Dec;28(2):202-13
references.pmid: 1461123
references.citation: Diabet Med. 2010 Aug;27(8):911-7
references.pmid: 20653749
references.citation: Circ Res. 1993 Nov;73(5):829-38
references.pmid: 8403254
references.citation: Circ Cardiovasc Imaging. 2012 May 1;5(3):341-8
references.pmid: 22492483