Thrombin-Induced Platelet-Fibrin Clot Strength Identified by Thrombelastography: A Novel Prothrombotic Marker of Coronary Artery Stent Restenosis

Background and ObjectiveIn-stent restenosis (ISR) is a limitation of percutaneous coronary intervention and has been linked to specific clinical and angiographic variables. We aimed to simultaneously assess thrombosis biomarkers and lipid levels in patients with and without ISR. MethodsConsecutive patients (n=170) with a history of coronary stenting undergoing elective angiography were studied. Blood samples for thrombelastography, light transmittance aggregometry, and lipid levels were obtained prior to cardiac catheterization. ResultsSixty-nine patients (41%) had ISR (>50% luminal diameter stenosis). Among patients with ISR, 40 (58%) had ISR in more than one stent bed. Patients with ISR were more often female (37.7% vs. 21.8%, P=0.04), had higher thrombin-induced platelet-fibrin clot strength (TIP-FCS) (69.9mm vs. 65.6mm, P<0.001), and a higher ApoB/A1 ratio (0.65 vs. 0.59, P=0.03). In patients on dual antiplatelet therapy (n=86), there were no differences in ADP-, arachidonic acid-, and collagen-induced platelet aggregation between groups. The frequency of patients with ISR increased with TIP-FCS quartiles and by ROC analysis, TIP-FCS=67.0mm was the cutpoint for identification of ISR (AUC=0.80 (95%CI 0.73-0.87, P<0.0001). By multivariate analysis, TIP-FCS 67.0mm strongly associated with ISR (OR=7.3, P=0.004). ConclusionPatients with ISR identified at the time of cardiac catheterization have a prothrombotic phenotype indicated by high TIP-FCS, a novel marker. Studies to confirm the prognostic utility of high TIP-FCS for the development of ISR are ongoing. (J Interven Cardiol 2016;29:168-178)