Author ORCID Identifier
Myers - https://orcid.org/0000-0002-2934-2624
Pipinos - https://orcid.org/0000-0001-6873-6346
Document Type
Article
Publication Date
8-21-2019
Abstract
Background
Patients with peripheral artery disease (PAD) who experience intermittent claudication report a range of symptoms. Patients with symptoms other than classically described intermittent claudication may be at the highest risk for functional decline and mobility loss. Therefore, technologies allowing for characterization of PAD severity are desirable. Near-infrared spectroscopy (NIRS) allows for measurements of muscle heme oxygen saturation (StO2) during exercise. We hypothesized lower extremities affected by PAD would exhibit distinct NIRS profiles as measured by a low-cost, wireless NIRS device and that NIRS during exercise predicts walking limitation.Methods
We recruited 40 patients with PAD and 10 control participants. All patients with PAD completed a computed tomographic angiography, 6-minute walk test, and a standardized treadmill test. Controls completed a 540-second treadmill test for comparison. StO2 measurements were continuously taken from the gastrocnemius during exercise. Variables were analyzed by Fischer's exact, χ2, Wilcoxon rank-sum, and Kruskal-Wallis tests as appropriate. Correlations were assessed by partial Spearman correlation coefficients adjusted for occlusive disease pattern.Results
Patients with PAD experienced claudication onset at a median of 108 seconds with a median peak walking time of 288 seconds. The baseline StO2 was similar between PAD and control. The StO2 of PAD and control participants dropped below baseline at a median of 1 and 104 seconds of exercise, respectively (P < .0001). Patients with PAD reached minimum StO2 earlier than control participants (119 seconds vs 522 seconds, respectively; P < .001) and experienced a greater change in StO2 at 1 minute of exercise (−73.2% vs 8.3%; P < .0001) and a greater decrease at minimum exercise StO2 (−83.4% vs −16.1%; P < .0001). For patients with PAD, peak walking time, and 6-minute walking distance correlated with percent change in StO2 at 1 minute of exercise (r = −0.76 and -0.67, respectively; P < .001) and time to minimum StO2 (r = 0.79 and 0.70, respectively; P < .0001).Conclusions
In this initial evaluation of a novel, low-cost NIRS device, lower extremities affected by PAD exhibited characteristic changes in calf muscle StO2, which differentiated them from healthy controls and were strongly correlated with walking impairment. These findings confirm and expand on previous work demonstrating the potential clinical value of NIRS devices and the need for further research investigating the ability of low-cost NIRS technology to evaluate, diagnose, and monitor treatment response in PAD.Journal Title
Journal of Vascular Surgery
Volume
71
Issue
3
First Page
946
Last Page
957
Recommended Citation
Fuglestad MA, Hernandez H, Gao Y, Ybay H, Schieber MN, Brunette KE, Myers SA, Casale GP, Pipinos II. A low-cost, wireless near-infrared spectroscopy device detects the presence of lower extremity atherosclerosis as measured by computed tomographic angiography and characterizes walking impairment in peripheral artery disease. Journal of Vascular Surgery. 2019 Aug 21;. doi: 10.1016/j.jvs.2019.04.493. [Epub ahead of print] PubMed PMID: 31445826. https://doi.org/10.1016/j.jvs.2019.04.493
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Comments
This is an Accepted Manuscript of an article published by Elsevier in Journal of Vascular Surgery on [August 21, 2019], available online: https://doi.org/10.1016/j.jvs.2019.04.493