Serum Free Indoxyl Sulfate Associated with In-stent Restenosis After Coronary Artery Stentings

Uremic toxins, including P-cresyl sulfate (PCS) and indoxyl sulfate (IS), have been found to participate in the process of atherosclerosis and patient mortality. We aim to discover if uremic toxins are related to in-stent restenosis in patients with coronary artery disease after stent implantation. We enrolled 214 patients who received coronary angioplasty with stenting and follow-up angiography between November 1995 and June 2011 with a total of 293 lesions divided into bare metal stent (BMS) or drug-eluting stent (DES) groups. Patients' basic information and total and free form IS and PCS were used to correlate with the late loss (LL) and loss index (LI). Significantly higher LL and LI in the BMS group compared with the DES group (1.10 vs. 0.45 mm, p < 0.001, and 0.46 vs. 0.19, p < 0.001, respectively). The unadjusted correlation revealed a positive relationship between log-normalized free IS and LL, LI in the DES group (p = 0.001). After adjustment for multiple variables, the log-normalized free IS still presented as an independent predictor for the LL and LI (p = 0.012 and p = 0.031). Free IS is an independent predictor for coronary restenosis in patients receiving DES implantations. However, among patients undergoing BMS stentings, uremic toxin is not a predictor of the intracoronary restenosis.