Risk Factors Analysis And Treatment Strategy Of Late And Very Late In-Stent Thrombosis In Patients After Drug-Eluting Stents Implantation Through Optical Coherence Tomography

BackgroundPercutaneous coronary intervention with stenting is the most widely performed procedure for the treatment of symptomatic coronary disease. Drug-eluting stents (DES) have minimized the limitations of bare-metal stents (BMS), which reduced the in-stent restenosis and target lesion revascularization. Nevertheless, there remain serious concerns about late complications such as late stent thrombosis (LST) and very late thrombosis (VLST). Although the incidence rate was lower, LST and VLST are still potential danger for patients. Preventing the incidence of LST and VLST are still a hot and difficult spot in the coronary intervention.Due to its high resolution (10～15μm), the ability of OCT was able to characterize human atherosclerotic plaques compared to histology. OCT can adequately detect individual stent struts and characterize their apposition to the vessel wall and Acute damage(disrupted intima, intraluminal thrombus and tissue prolapse) after stent implantation. OCT allows an accurate assessment in vivo of strut tissue coverage, neointimal hyperplasia, Restenotic tissue characterization and stent thrombosis at follow up. OCT is an important and useful technology for exploring the etiology and evaluating the LST and VLST.ObjectiveTo analysis the risk factors of late and very late in-stent thrombosis in patients after drug-eluting stents implantation by optical coherence tomography. We investigated the treatment strategy and reduced late complications for patients.MethodsWe retrospctively reviewed patients undergoing PCI who admitted in our hospital from2010to.2013.9patient were diagnosied LST or VLST by coronary angiography and/or OCT which named ST group. the patients with matched age and gender (2:1),and38patients had no in-stent thrombosis as control group(CL group). Their clinical, coronary angiography and OCT data were recorded and an Excel database was established to analysis the major control lable risk factors of LST and VLST. Logistic regression analysis was performed to identify the independent risk factors of LST and VLST. The treatment stragegy was made for patient according of OCT, to make sure no in-stent thrombosis and the stent strut apposition was completed.ResultsLST or VLST of patients occurred at a median of17.42±5.66months after PCI. As compared with CL group, ST group had more diabetes mellitus (DM), AMI and higher fasting blood surge, lower LVEF; all P<0.01. CAG and OCT showed that ST group had more stent numbers, stent length, mal-apposition and uncovered struts. logistic regression analysis indicated that the independent risk factors of LST and VLST were DM (OR:7.256;95%CI:1.721-30.591; P<0.01)、AMI (OR:7.642;95%CI:1.412-41.152; P<0.01)、stent number (OR1.645;95%CI:1.106-2.447; P=0.014)、stent length (OR:13.285;95%CI:3.198-55.189; P<0.01), stent mal-apposition (OR5.132;95%CI:4.800-5.464; P=0.001)、stent strut uncovered (OR12.549;95%CI:3.657-43.067; P<0.01). Normal LVEF was a protective factor for LST and VLST (OR:0.714;95%CI:0,574-0.887; P=0.002).We performed PTCA for6patients and PCTA with PCI for13patients according of OCT. There were stents without thrombosis and mal-apposition.ConclusionDM、AMI、more stent number、longer stent、stent mal-apposition、stent strut uncovered were risk factors of late and very late in-stent thrombosis in patients after drug-eluting stents implantation. Normal LVEF was protective factor for LST or VLST. therefore, we may prevent LST and VLST after DES implantation by improving heart function、reducing the rate of mal-apposition and promoting re-endothelialization.