Preoperative inflammatory status as a predictor of primary patency after femoropopliteal stent implantation

Objective The purpose of this study was to evaluate the impact of preoperative inflammatory status, as determined by complete blood count test parameters, on 12- and 24-month patency of femoropopliteal stenting for peripheral arterial disease. Methods We retrospectively analyzed baseline clinical and angiographic data among 138 patients (median age, 73 years; 46% female) from 2005 to 2014 at our institution with preoperative complete blood count test values and information of patency for at least 12 months after first-time femoropopliteal stenting. Patients were stratified into tertiles on the basis of preoperative blood counts to evaluate associations with in-stent restenosis (ISR) leading to loss of primary patency, defined by a Doppler velocity ratio ≥2.5:1, computed tomography angiography demonstrating ≥50% luminal narrowing within the stent, or reintervention. Results Univariate analysis determined that the 81 patients (59%) who experienced ISR within 12 months had significantly higher preoperative white blood cell (WBC), platelet, neutrophil, and lymphocyte counts than the 57 patients (41%) whose stents remained patent for longer than 12 months (8.7 vs 6.7 [P <.001], 246 vs 184 [P <.001], 5.7 vs 4.7 [P =.001], and 1.8 vs 1.2 [P =.004], respectively). Compared with patients in the lower WBC tertile (n = 45) who had a median patency of 19.4 months, those in the upper WBC tertile (n = 44) had a median patency of only 7.0 months and a 3.3-fold increased risk for ISR after adjusting for age, sex, lesion type, TransAtlantic Inter-Society Consensus II score, tibial vessel runoff, antiplatelet therapy, presence of diabetes, critical limb ischemia, adjunct procedures, hyperlipidemia, and end-stage renal disease in multivariate analysis (P <.001). Compared with patients in the lower platelet tertile (n = 45) who had a median patency of 16.9 months, those in the upper platelet tertile (n = 47) had a median patency of 7.1 months and a 2.7-fold increased adjusted risk (P =.001). Compared with patients in the lower neutrophil tertile (n = 33) who had a median patency of 14.3 months, those in the upper neutrophil tertile (n = 33) had a median patency of 6.2 months and a 3.2-fold increased adjusted risk (P =.001). After adjusting for covariates, patients divided into tertiles by lymphocyte counts exhibited no significant differences for ISR. Conclusions Routine preoperative tests that determine baseline inflammatory status may provide strong clinical utility in assessing potential risk stratification of patients for ISR after femoropopliteal stenting. Circulating WBCs, platelets, and neutrophils may be important inflammatory mediators of ISR.