Coronary endothelial dysfunction is associated with a reduction in coronary artery compliance and an increase in wall shear stress.
OBJECTIVE
Endothelial dysfunction is associated with arterial stiffness in large arteries. The purpose of this study was to investigate the association between coronary endothelial dysfunction, coronary artery compliance and wall shear stress in patients with early atherosclerosis.


METHODS
Coronary endothelial function was assessed according to responses to intracoronary acetylcholine in 120 patients without significant coronary stenosis. Acceleration of peak velocity (ACC), which is inversely related to coronary artery compliance, was derived from coronary flow velocity spectra, and wall shear rate (WSR) was calculated. Measurements were performed at baseline and after intracoronary nitroglycerin in order to eliminate the contribution of vascular smooth muscle tone to coronary artery compliance.


RESULTS
In all patients, heart rate significantly increased (72+/-1 to 77+/-1 bpm, p<0.01) and mean arterial pressure decreased (97+/-2 to 93+/-1 mm Hg, p<0.01) after nitroglycerin. Coronary blood flow (CBF) and resistance were not significantly changed, but the diastolic to systolic velocity ratio increased significantly (2.15+/-0.08 to 5.36+/-0.61, p<0.01). Patients with abnormal endothelial function (n=70) had a higher WSR at baseline (559+/-41 vs 440+/-26 s(-1), p<0.05) and after nitroglycerin (457+/-41 vs 339+/-29 s(-1), p<0.05), and a higher ACC after nitroglycerin (3.9+/-0.4 vs 2.8+/-0.4 m/s(2), p<0.05) than patients with normal function (n=50).


CONCLUSIONS
The current study demonstrates that intracoronary nitroglycerin does not contribute to an increase of CBF but alters the phasic coronary flow pattern. Furthermore, early coronary atherosclerosis characterised by endothelial dysfunction is associated with a decrease in coronary artery compliance and an increase in wall shear stress. Therefore, coronary wall properties are affected early in the atherosclerosis process.
Takumi
Takuro
T
Division of Cardiovascular Disease, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA. lerman.amir@mayo.edu
Yang
Eric H
EH
Mathew
Verghese
V
Rihal
Charanjit S
CS
Gulati
Rajiv
R
Lerman
Lilach O
LO
Lerman
Amir
A
D001783:Blood Flow Velocity / Q000187:drug effects; D003187:Compliance; D003324:Coronary Artery Disease / Q000503:physiopathology*; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000494:pharmacology; D013314:Stress, Mechanical; D014655:Vascular Resistance / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; D005996:Nitroglycerin
Circulation. 2007 May 22;115(20):2621-7
17485580
Circulation. 1998 Nov 10;98(19):2000-3
9808596
J Vasc Res. 2006;43(3):251-69
16491020
Hypertension. 1998 Aug;32(2):351-5
9719066
Hypertension. 2006 Oct;48(4):602-8
16940223
Hypertension. 1995 Sep;26(3):503-8
7649589
Am J Hypertens. 2003 Dec;16(12):1000-5
14643572
Circulation. 2006 Feb 7;113(5):664-70
16461839
Arterioscler Thromb Vasc Biol. 2006 Jan;26(1):106-11
16239595
Lancet. 2001 Oct 27;358(9291):1400-4
11705484
Arterioscler Thromb Vasc Biol. 2003 Feb 1;23(2):168-75
12588755
Am J Physiol Heart Circ Physiol. 2000 Jan;278(1):H175-83
10644597
J Am Coll Cardiol. 2007 Aug 28;50(9):852-8
17719471
J Cardiovasc Pharmacol. 2000 Dec;36(6):764-9
11117377
Circulation. 2006 Feb 7;113(5):657-63
16461838
Circulation. 1981 Dec;64(6):1101-7
6794933
Hypertension. 2005 Jul;46(1):227-31
15867142
Circulation. 2000 Apr 25;101(16):1899-906
10779454
Heart. 2008 Jun;94(6):e20
17947361
Circulation. 2003 Jul 29;108(4):438-44
12860915
Circulation. 2002 Jan 15;105(2):213-7
11790703
Hypertension. 1999 Dec;34(6):1237-41
10601124
Am J Hypertens. 2002 Apr;15(4 Pt 1):321-5
11991217
Circulation. 1992 Jun;85(6):2296-304
1591844
Circulation. 2007 Feb 6;115(5):609-16
17242283
Am J Physiol. 1990 Feb;258(2 Pt 2):H515-20
2106798
Atherosclerosis. 2007 Oct;194(2):e123-30
17145061
Am J Hypertens. 1997 Oct;10(10 Pt 1):1175-89
9370391
Circulation. 2000 Mar 7;101(9):948-54
10704159
Circulation. 1996 Dec 15;94(12):3263-70
8989139
Am J Cardiol. 2003 Aug 15;92(4):395-9
12914868
Stroke. 2007 Apr;38(4):1374-6
17332443