Evaluation of Whole Blood Viscosity to Predict Stent Restenosis in Patients with Coronary Artery Disease.

Background: This study investigated the relationship between whole blood viscosity (WBV) and in-stent restenosis (ISR) in patients with prior coronary stent implantation who underwent coronary angiography (CAG) for chronic coronary syndrome (CCS).

Methods: In this retrospective case-control study, 802 patients who underwent CAG with suspected ISR were included. In-stent restenosis was defined as ≥50% stenosis within the stent or within 5 mm of its edges. Patients were divided into an ISR group (n = 342) and a control group without ISR (n = 460). Whole blood viscosity was calculated using both high-shear rate viscosity (HSR) and low-shear rate viscosity (LSR).

Results: Whole blood viscosity levels were significantly higher in the ISR group for both HSR (16.8 ± 1.0 vs. 15.6 ± 0.9 cP, P < .001) and LSR (83.1 ± 8.4 vs. 80.8 ± 8.0 cP, P < .001). Receiver-operating characteristic curve (ROC) analysis showed strong predictive power for ISR (area under the curve [AUC] 0.84 for LSR and 0.82 for HSR). Kaplan-Meier analysis demonstrated significantly lower ISR-free survival in patients with high WBV (P < .001). Multivariate Cox regression identified both HSR and LSR as independent predictors of ISR.

Conclusion: Increased WBV is independently linked to ISR and may contribute to its development via endothelial inflammation and vascular remodeling. Whole blood viscosity demonstrates potential utility as a biomarker for the identification of CCS patients susceptible to ISR.