■ FEATURED ABSTRACT Correlation of treadmill test outomes with symptom improvement after treatment for aortoiliac claudication

Purpose The CLEVER Study (Claudication: Exercise Vs. Endoluminal Revascularization) previously reported superior treadmill peak walking time at 6 months when claudicants are treated with supervised exercise compared with stent revascularization. Conversely, it also showed better symptom improvement at 6 months for stent than supervised exercise. The purpose of this post-hoc analysis is to examine the relationship of disease-specific QOL (i.e., symptom) improvement with treadmill test outcomes, using data from CLEVER Study participants. Materials and Methods Multivariable regression analyses were done on treadmill test walking performance (peak walking performance and claudication onset time) using the 5 scales of the Peripheral Artery Questionnaire (PAQ) and Walking Impairment Questionnaire (WIQ), to examine the correlation and treatment group interaction effects. Results The correlation between change in symptoms and change in peak treadmill test walking performance showed a significant interaction effect with treatment group. Symptom improvement correlated with peak treadmill walking performance for those treated with stents but not for those treated with supervised exercise. There was a much larger improvement in symptoms for each minute of improvement in peak treadmill walking for stent compared with supervised exercise. In contrast, there was no significant treatment group interaction for claudication onset time on the treadmill, and improvements in symptoms correlated well with increases in claudication onset time, with no significant interaction with treatment group for any of the 5 scales. Conclusion Six month results from the CLEVER study show that although supervised exercise resulted in superior peak treadmill walking than stent revascularization, peak treadmill walking did not correlate with improved symptoms in that treatment group, whereas it did for the stent group. Treadmill claudication onset time may be a better endpoint for claudication treatment strategy trials, because symptom improvement and walking performance are both measured by it, independent of treatment group.