Original Research
Proximal Superficial Femoral Artery Occlusion, Collateral Vessels, and Walking Performance in Peripheral Artery Disease

https://doi.org/10.1016/j.jcmg.2012.10.024Get rights and content
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Objectives

We studied associations of magnetic resonance imaging (MRI)-measured superficial femoral artery (SFA) occlusions with functional performance, leg symptoms, and collateral vessel number in peripheral artery disease (PAD). We studied associations of collateral vessel number with functional performance in PAD.

Background

Associations of MRI-detected SFA occlusion and collateral vessel number with functional performance among individuals with PAD have not been reported.

Methods

A total of 457 participants with an ankle brachial index (ABI) <1.00 had MRI measurement of the proximal SFA with 12 consecutive 2.5-μm cross-sectional images. An occluded SFA was defined as an SFA in which at least 1 segment was occluded. A nonoccluded SFA was defined as absence of any occluded slices. Collateral vessels were visualized with magnetic resonance angiography. Lower extremity functional performance was measured with the 6-min walk, 4-m walking velocity at usual and fastest pace, and the Short Physical Performance Battery (SPPB) (0 to 12 scale, 12 = best).

Results

Adjusting for age, sex, race, comorbidities, and other confounders, the presence of an SFA occlusion was associated with poorer 6-min walk performance (1,031 vs. 1,169 feet, p = 0.006), slower fast-paced walking velocity (1.15 vs. 1.22 m/s, p = 0.042), and lower SPPB score (9.07 vs. 9.75, p = 0.038) compared with the absence of an SFA occlusion. More numerous collateral vessels were associated with better 6-min walk performance (0 to 3 collaterals—1,064 feet, 4 to 7 collaterals—1,165 feet, ≥8 collaterals—1,246 feet, p trend = 0.007), faster usual-paced walking speed (0 to 3 collaterals—0.84 m/s, 4 to 7 collaterals—0.88 m/s, ≥8 collaterals—0.91 m/s, p trend = 0.029), and faster rapid-paced walking speed (0 to 3 collaterals—1.17 m/s, 4 to 7 collaterals—1.22 m/s, ≥8 collaterals—1.29 m/s, p trend = 0.002), adjusting for age, sex, race, comorbidities, ABI, and other confounders.

Conclusions

Among PAD participants, MRI-visualized occlusions in the proximal SFA are associated with poorer functional performance, whereas more numerous collaterals are associated with better functional performance. (Magnetic Resonance Imaging to Identify Characteristics of Plaque Build-Up in People With Peripheral Arterial Disease; NCT00520312)

Key Words

atherosclerotic plaque
intermittent claudication
peripheral arterial disease
physical functioning

Abbreviations and Acronyms

ABI
ankle brachial index
BMI
body mass index
MRA
magnetic resonance angiography
MRI
magnetic resonance imaging
PAD
peripheral artery disease
SFA
superficial femoral artery
SPPB
Short Physical Performance Battery

Cited by (0)

Supported by the National Heart Lung and Blood Institute (R01-HL083064) and (R01-HL109244), the Intramural Research Program of the National Institute on Aging, and the Jesse Brown VA Medical Center. Dr. Kramer receives research support from Siemens Healthcare. Dr. Yuan receives research support from VP Diagnostics and from Philips Healthcare; and is a consultant for ImagePace. Dr. Berry is on the Speakers' Bureau of Merck. Dr. Carr receives research support from Siemens and Lantheus Medical Imaging. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.