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CC BY 4.0 · Aorta (Stamford) 2016; 04(05): 156-161
DOI: 10.12945/j.aorta.2016.16.020
Original Research Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Lower Aorto-Iliac Bifurcation Position and Incident Cardiovascular Disease: A Multi-Ethnic Study of Atherosclerosis (MESA)

Nketi I. Forbang
1   Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, California, USA
,
Matthew A. Allison
1   Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, California, USA
2   Department of Vascular Surgery, San Diego Veterans Administration Health Care Systems, La Jolla, California, USA
,
Michael H. Criqui
1   Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, California, USA
› Author Affiliations
Further Information

Publication History

18 April 2016

23 October 2016

Publication Date:
24 September 2018 (online)

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Abstract

Background: With increasing age, a downward shift of the aorto-iliac bifurcation relative to the lumbar spine occurs. A lower bifurcation position is an independent marker for adverse vascular aging and is associated with increased burden of cardiovascular disease (CVD) risk factors; however, the associations between lower bifurcation position and CVD events remain unknown.

Methods: Abdominal computed tomography scans were used to measure the aorto-iliac bifurcation distance (AIBD, distance from the aorto-iliac bifurcation to the L5/S1 disc space). Cox proportional hazard analysis was used to determine the independent hazard of a lower bifurcation position (smaller AIBD) for incident coronary heart disease (CHD, defined as myocardial infarction, resuscitated cardiac arrest, or sudden cardiac death), CVD (CHD plus stroke or stroke death), and all-cause mortality (ACM).

Results: In the 1,711 study participants (51% male), the mean AIBD was 26 ± 15 mm. After a median follow-up of 10 years, 63 (3.7%) developed CHD, 100 (5.8%) developed CVD, and 129 (7.5%) were deceased. Compared to the 4th quartile of AIBD (highest bifurcation position), participants in the 1st quartile (lowest bifurcation position) had increased risk for CHD (hazard ratio (HR) = 1.5, 95% confidence interval (CI): 0.8-3.0, P = 0.2), CVD (HR = 1.8, 95% CI: 0.9-2.7, P = 0.1), and ACM (HR = 2.2, 95% CI: 1.3-3.6, P = 0.01). After adjustments for CVD risk factors, the HR for ACM was no longer significant.

Conclusion: Despite being an independent marker for adverse vascular changes in the aorta, a lower aorto-iliac bifurcation position was not independently associated with future CVD events. The opposing effects of atherosclerosis and stiffness in the aorta may, in part, explain our null findings.

Key Words

Aorto-iliac bifurcation distance - Cardiovascular disease events - Atherosclerosis arterial stiffness
 

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