Relation of coronary artery plaque location to extent of coronary artery disease studied by computed tomographic angiography
Received 16 October 2009; accepted 9 January 2010. published online 21 January 2010.
Background
Distal coronary artery disease (CAD) is less amenable to surgery or stenting compared with proximal disease. However, little is known about the epidemiology of distal versus proximal CAD.
Methods
We determined the prevalence and factors associated with proximal, mid, and distally located plaque in the left anterior descending, left circumflex, and right coronary arteries in 418 subjects without prior CAD history who underwent coronary computed tomographic angiography for symptoms or stress test results. Clinical characteristics and coronary artery calcium (CAC) scores were also determined.
Results
Most subjects (88%) had plaque, but only 18% of plaques were associated with stenosis >50%. In subjects with single-vessel plaque, only 7% had distal plaque, whereas 75% had proximal plaque. With 3-vessel plaque, 70% had distal and 100% had proximal plaques. Of subjects with a single location of plaque along a vessel, most had proximal plaque (69%); isolated distal-vessel plaque was rare (2%). Distal plaque was dominantly found in association with both proximal and mid plaque (88%). After multivariable adjustment for demographics, traditional, and nontraditional risk factors, both increasing number of vessels with plaque and clinically significant CAC scores were independently associated with higher odds of distal plaque, whereas associations of traditional risk factors were weaker. Distal plaque was independently associated with stenosis > 50%.
Conclusion
These data support the concept that early lesions are most often proximal and that CAC scoring may be a poor screening tool for detecting proximal disease. Furthermore, distal lesions are more associated with advanced disease than with traditional cardiovascular risk factors.
aDepartment of Medicine, University of California, San Francisco, CA, USA
bMetabolism Section 111F, Veterans Affairs Medical Center, 4150 Clement Street, San Francisco, CA 94121, USA
cDenver Veterans Affairs Medical Center and School of Medicine, University of Colorado, Denver, CO, USA
dLos Angeles Biomedical Research Institute, Torrance, CA, USA
eDepartment of Medicine, Boston Medical Center, Boston, MA, USA
Corresponding author.
Conflict of interest: The authors report no conflicts of interest.
Supported in part by a Veterans Affairs Health Services Research and Development Service Research Career Development Award (RCD 04-115-2 to P.D.V.), the Albert L. and Janet A. Schulz Supporting Foundation, and with resources and the use of facilities of the VA Medical Center, San Francisco, CA.
ABSTRACT