Risk Factor Analyse And Correlated Preventive Strategy Evaluation Of Early Stent Thrombosis

Background Drug-eluting stents (DES) have significantly reduced the restenosis and target lesion revascularization rate, but stent thrombosis (ST) is still a potential danger for patients. Preventing the incidence of ST is still a hot and difficult spot in the coronary intervention.Objective (1) To analyze the main risk factors of early stent thrombosis (EST). (2) To evaluate the guidance of OCT in the optimization of DES implantation. (3) To observe the relationship between fluid infusion speed and RPA during perioperative of PCI. (4) To investigate the effective of optimizing the quality of intervention and perioperative management to prevent EST.Methods (1) A cohort of consecutive patients treated with PCI from 2004 to 2008 were retrospectively analysized. Their clinical and intervention data were recorded and an Excel database was established to analysis the major controllable risk factors of EST. (2) The PCI and OCT data of the patients who have finished OCT examinations and stent implantion from 2007 to 2009 were studied, and the optimization of DES adherence, intimal prolapse degree and dissection were analysized. (3) A prospective and randomized controlled trial was designed to evaluate the effect of different fluid infusion speed on RPA.Results(1) Four patients (0.70%) in 570 patients with coronary heart disease treated with PCI had EST during an average of 4.25 days after DES implantion.(2) Main risk factors of EST include aging, smoking heavy, stent malapposition and perioperative mismanagement.(3) Persistent chest pain and low BP occured in patients with EST. Some had cardiogenic shock (25%) and refractory ventricular fibrillation (25%). Even through treated with emergency treatments,50% mortality were still existed. (4) During OCT examination, only 7 patients had transient angina and mild ST segment changes. There were no serious cardiovascular events.(5) There was no significant difference with stent adherent distance between Cypher and EXCEL stent, as well as Partner and TAXUS stent (P >0.05). There was significant difference between Cyphe/EXCEL group with Partner/TAXUS group (P<0.05).(6) The distance between the vessel wall and stent after post-dilatation was significantly shorter than that of the named stent expansion in kinds of stents (P <0.05). The incidence of intimal prolapse and dissection after post-dilatation were significantly less than that of named stent expansion (P<0.05).(7) Compared with the conventional infusion, rapid infusion did not increase bleeding, heart failure and other complications (P> 0.05).(8) RPA in rapid infusion group was significantly lower than that of conventional infusion group after four hours (P<0.05).(9) There were 3 patients who had angina after PCI in the conventional fluid group. EST was suspected because of insufficient body fluid capacity. Emergency angiography excluded thrombus, but symptoms disappeared after rapid infusion.Conclusions(1) Optimization of DES implantation and perioperative management are major controllable risk factors of EST.(2) The distance of stent adherence depends on the total thickness of stents.(3) Post-dilatation can reduce stent malapposition, depress the incidence of intimal prolapse and dissection.(4) Rapid fluid influsion can reduce perioperativ RPA, and profiting to prevent EST.(5) Optimizing stent implantion and perioperative management could be effective measures to reduce EST.