Abstract 4414: Activated Platelet is Associated With Subclinical Stent Thrombosis Detected by Optical Coherence Tomography
Backgrounds: While stent thrombosis is a critical issue in the drug-eluting stent era, there are few monitoring markers for stent thrombosis. Optical coherence tomography (OCT) introducing as a high-resolution modality allows us to assess plaque characteristics, including in-stent micro-thrombus. We hypothesized that in vivo activated platelet was associated with in-stent thrombus formation. The aim of this study was to investigate the relationship between in vivo platelet activity and in-stent thrombus formation assessed by OCT.
Methods: We enrolled 54 patients who were treated with coronary stent. OCT was performed at a 8-month follow-up angiography. The frequency of uncovered struts was assessed by OCT. Patients were divided into a thrombus group and a non-thrombus group according to OCT findings. Platelet function was monitored by light transmittance platelet aggregometry using adenosine 5′-diphosphate (ADP). Platelet factor 4 (PF4) was measured as a marker of activated platelet.
Results: Thrombus was observed in 12 (22%) by OCT. No significant differences were found in patient’s characteristics between the 2 groups. There were no differences in the frequency of uncovered struts (1.9±2.5% vs. 1.1±1.9%, p=0.14) and maximal aggregation with ADP (33.7±6.5% vs. 33.9±8.0%, p=0.93) between the 2 groups. However, PF4 levels in the thrombus group were significantly higher than those in the non-thrombus group (31.4±21.7ng/mL vs. 12.8±12.8ng/mL, p=0.005).
Conclusion: OCT can indentify subclinical stent thrombosis. Activated platelet might be associated with subclinical stent thrombosis. PF4 could be used as a monitoring marker for in-stent thrombosis.