Hobaus C, et al. - Whether YKL-40 (an inflammatory marker secreted by macrophages and is expressed in atherosclerotic plaques) is associated with peripheral arterial disease (PAD) severity as well as cardiovascular long-term mortality, was determined. Using Kaplan-Meier and Cox regression, seven-year follow-up was performed in elderly PAD patients (age 69 ± 10.4, 33.7% women, Fontaine stage I-II) with YKL-40 measured at baseline. An independent association of increased YKL-40 levels with poor long-term cardiovascular survival was found. YKL-40 remained significantly related to cardiovascular and all-cause mortality even after multivariable adjustment for gender, patient age, known carotid artery disease, known coronary artery disease, smoking status, systolic blood pressure, HbA_1c, low-density lipoprotein cholesterol, estimated glomerular filtration rate, aspartate aminotransferase, and C-reactive protein. In PAD, correlation of YKL-40 with patients' ankle-brachial index was seen in the absence of mediasclerosis.