Noninvasive assessment of coronary vasodilation using cardiovascular magnetic resonance in patients at high risk for coronary artery disease.
BACKGROUND
Impaired coronary vasodilation to both endothelial-dependent and endothelial-independent stimuli have been associated with atherosclerosis. Direct measurement of coronary vasodilation using x-ray angiography or intravascular ultrasound is invasive and, thus, not appropriate for asymptomatic patients or for serial follow-up. In this study, high-resolution coronary cardiovascular magnetic resonance (CMR) was used to investigate the vasodilatory response to nitroglycerine (NTG) of asymptomatic patients at high risk for CAD.


METHODS
A total of 46 asymptomatic subjects were studied: 13 high-risk patients [8 with diabetes mellitus (DM), 5 with end stage renal disease (ESRD)] and 33 age-matched controls. Long-axis and cross-sectional coronary artery images were acquired pre- and 5 minutes post-sublingual NTG using a sub-mm-resolution multi-slice spiral coronary CMR sequence. Coronary cross sectional area (CSA) was measured on pre- and post-NTG images and % coronary vasodilation was calculated.


RESULTS
Patients with DM and ESRD had impaired coronary vasodilation to NTG compared to age-matched controls (17.8 +/- 7.3% vs. 25.6 +/- 7.1%, p = 0.002). This remained significant for ESRD patients alone (14.8 +/- 7.7% vs. 25.6 +/- 7.1%; p = 0.003) and for DM patients alone (19.8 +/- 6.3% vs. 25.6 +/- 7.1%; p = 0.049), with a non-significant trend toward greater impairment in the ESRD vs. DM patients (14.8 +/- 7.7% vs. 19.8 +/- 6.3%; p = 0.23).


CONCLUSIONS
Noninvasive coronary CMR demonstrates impairment of coronary vasodilation to NTG in high-risk patients with DM and ESRD. This may provide a functional indicator of subclinical atherosclerosis and warrants clinical follow up to determine prognostic significance.
Department of Medicine, Division of Cardiovascular Medicine, Stanford University, Stanford, USA. pnguyen@cvmed.stanford.edu
Patricia K
PK
Nguyen
Craig
C
Meyer
Jan
J
Engvall
Phillip
P
Yang
Michael V
MV
McConnell
D001794:Blood Pressure / Q000187:drug effects; D003324:Coronary Artery Disease / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D003331:Coronary Vessels / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology*; D003920:Diabetes Mellitus / Q000503:physiopathology; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007676:Kidney Failure, Chronic / Q000503:physiopathology; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin; D012307:Risk Factors; D012737:Sex Factors; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents
D014665:Vasodilator Agents; D005996:Nitroglycerin