White matter damage of the brain is associated with poor outcome in vascular surgery patients with claudication: a pilot study.

OBJECTIVE: Peripheral arterial disease (PAD) is a systemic atherosclerotic syndrome with high post-operative morbidity and mortality. Fractional anisotropy (FA), an index measured by magnetic resonance diffusion tensor imaging (DTI), has been shown to be exceedingly sensitive to microstructural damage in brain white matter tracts. It is hypothesized that pre-operative white matter damage is more extensive in PAD patients scheduled for vascular surgery who experience an adverse long-term outcome.

METHODS: Preoperative FA values were obtained in 24 consecutive PAD patients (age >40 years) scheduled for elective infrainguinal revascularization surgery and in 15 healthy age matched participants. All patients had their clinical history taken and underwent physical examination and laboratory tests. After surgery, patients were followed for a median of 52 months (range 40-63) and major adverse cardiovascular and cerebrovascular events (MACCE) were recorded.

RESULTS: There were no statistically significant differences in baseline demographic or clinical variables between the MACCE group and the non-MACCE group. During follow up, eight PAD patients suffered a MACCE and they had lower FA values than patients without MACCE or healthy controls (mean ± SD 0.370 ± 0.017 vs. 0.392 ± 0.023 vs. 0.412 ± 0.018, p = .036 and p = .00007, respectively). Voxelwise analysis of the FA data revealed diffuse spatial distribution of white matter damage in PAD patients. There was no statistically significant association between the FA values and other clinical variables.

CONCLUSION: Microstructural white matter damage was associated with poor outcome in PAD patients with claudication requiring surgical revascularization, and its extent may have clinical value in risk stratification.