Altered plasma fibrin clot properties are associated with in-stent thrombosis

Abstract

OBJECTIVES-: We sought to investigate whether patients with in-stent thrombosis (IST) display altered plasma fibrin clot properties. METHODS AND RESULTS-: We studied 47 definite IST patients, including 15 with acute, 26 subacute and 6 late IST, and 48 controls matched for demographics, cardiovascular risk factors, concomitant treatment and angiographic/stent parameters. Plasma clot permeability (Ks), which indicates a pore size, turbidity (lag phase, indicating the rate of fibrin clot formation, ΔAbsmax, maximum absorbance of a fibrin gel, reflecting the fiber thickness), lysis time (t50%) and maximum rate of d-dimer release from clots (D-Drate) were determined 2 to 73 (median 14.7) months after IST. Patients with IST had 21% lower Ks, 14% higher ΔAbsmax, 11% lower D-Drate, 30% longer t50% (all P<0.0001) and 5% shorter lag phase compared to controls (P=0.042). There were no correlations between clot variables and the time of IST or that from IST to blood sampling. Multiple regression analysis showed that Ks (odds ratio=0.36 per 0.1 μm, P<0.001), D-Drate (odds ratio=0.16 per 0.01 mg/L/min, P<0.001) and stent length (odds ratio=1.1 per 1 mm, P=0.043) were independent predictors of IST (R=0.58, P<0.001). CONCLUSIONS-: IST patients tend to form dense fibrin clots resistant to lysis, and altered plasma fibrin clot features might contribute to the occurrence of IST. © 2010 American Heart Association, Inc.