Progression of asymptomatic peripheral artery disease over 1 year

Abstract

The pathophysiology and time course of an individual converting from asymptomatic peripheral artery disease (PAD) to symptomatic claudication is unclear. The objectives of this study were: (1) to characterize the extent of atherosclerotic disease in individuals with an abnormal ankle-brachial index (ABI), but without claudication; and over 1 year of follow-up to (2) evaluate the progression of PAD using ultrasound imaging, (3) determine changes in the ABI and leg pain symptoms, and (4) correlate PAD progression with changes in the ABI and leg symptoms. We hypothesized that PAD progression would be associated with the development of claudication and changes in the ABI, 6-minute walk distance (6-MWD), and walking quality of life. Individuals with a reduced ABI but without typical intermittent claudication noted on community screening were invited to undergo baseline and 1-year follow-up assessment, including duplex ultrasound. The initial and repeat evaluations included measurement of the ABI, lower extremity duplex arterial mapping, and assessment of leg pain and functional status. Of the 50 people studied, 44 (88%) had significant atherosclerotic lesions in the lower extremity arteries, affecting 80 legs. A total of 33 of 50 individuals (66%) returned for the 1-year follow-up visit. On ultrasound examination, two of 18 normal legs developed PAD, and in 48 legs with PAD at baseline, 17 legs (35%) developed new or progressive lesions. Thirteen legs developed new claudication. Overall, there was no significant worsening in the ABI, 6-MWD, or the Walking Impairment Questionnaire (WIQ). However, legs with new lesions or lesion progression were significantly more likely to develop claudication, and the 13 legs (seven subjects) developing claudication showed a significant decline in the 6-MWD. In conclusion, these data indicate that a significant number of people with asymptomatic PAD show progression over 1 year, that such individuals are more likely to develop claudication, and that those developing claudication have a significant decrease in their 6-MWD.

Relative value of the Ankle-Brachial Index of intermittent claudication

“…Most individuals detected in population studies with an ABI ≤ 0.90 are asymptomatic, and in some studies only between 10% and 20% of them exhibited IC . However, a significant number of people with asymptomatic PAD show progression over one . None of this rules out the possibility that in populations exclusively of claudicants, most patients present an ABI of 0.90 to 0.50 (75% of our sample), and that, as in other series, the mean value is 0.60 .…”

Doppler ultrasonography of the lower extremity arteries: anatomy and scanning guidelines

“…Doppler US is the only noninvasive technique that does not require contrast enhancement, preparation of the patient before the study, or radiation exposure [1,2]. Doppler US is a good method for screening and follow-up, as well as for the definitive diagnosis of peripheral arterial disease [3-7]. Color Doppler US can easily identify arteries by finding round objects with regular pulsation and can be used to detect stenotic or occluded segments [4,8].…”

Ankle-brachial index predicts change over time in functional status in the San Diego Population Study

“…Although previous studies have examined associations of the ABI with functional status, the majority of these studies have been in participants with existing PAD 16–19,21,22 , have had small sample sizes 16,17,19,22 , were cross-sectional study designs 16–18,20,21,24,25 , or were not population-based 16–19,21,22 . In the current study, we showed that a lower baseline ABI predicts decline in functional status over 11 years in a multi-ethnic cohort of men and women.…”

“…The ABI was also significantly correlated with the SF-36 Physical Component Score 16,17 . Two longitudinal studies have also found the ABI associated with functional decline among those with known, prevalent PAD 22,23 .…”