The Effect of Cilostazol on Stent Thrombosis After Drug-Eluting Stent Implantation

BACKGROUND AND OBJECTIVES: Placement of drug-eluting stents (DES) can be complicated by stent thrombosis; prophylactic antiplatelet therapy has been used to prevent such events. We evaluated the efficacy of cilostazol with regard to stent thrombosis as adjunctive antiplatelet therapy. SUBJECTS AND METHODS: A total of 1,315 patients (846 males, 469 females) were prospectively enrolled and analyzed for the frequency of stent thrombosis. Patients with known risk factors for stent thrombosis, except diabetes and acute coronary syndrome, were excluded from the study. All patients maintained antiplatelet therapy for at least six months. To evaluate the effects of cilostazol as another option for antiplatelet therapy, triple antiplatelet therapy (aspirin+clopidogrel+cilostazol, n=502) was compared to dual antiplatelet therapy (aspirin+clopidogrel, n=813). Six months after stent placement, all patients received only two antiplatelet drugs: treatment either with cilostazol+aspirin (cilostazol group) or clopidogrel+aspirin (clopidogrel group). There were 1,033 patients (396 in cilostazol group and 637 in clopidogrel group) that maintained antiplatelet therapy for at least 12 months and were included in this study. Stent thrombosis was defined and classified according to the definition reported by the Academic Research Consortium (ARC). RESULTS: defined and classified according to the definition reported by the Academic Research Consortium (ARC). RESULTS: During follow-up (561.7+/-251.4 days), 15 patients (1.14%) developed stent thrombosis between day 1 to day 657. Stent thrombosis occurred in seven patients (1.39%) on triple antiplatelet therapy and four patients (0.49%) on dual antiplatelet therapy (p=NS) within the first six months after stenting. Six months and later, after stent implantation, one patient (0.25%) developed stent thrombosis in the cilostazol group, and three (0.47%) in the clopidogrel group (p=NS). CONCLUSION: During the first six months after DES triple antiplatelet therapy may be more effective than dual antiplatelet therapy for the prevention of stent thrombosis. However, after the first six months, dual antiplatelet treatment, with aspirin and cilostazol, may have a better cost benefit ratio for the prevention of stent thrombosis.

Elevated Troponin I after Implantation of Drug-Eluting Stents: Incidence, Predictors, and Prognostic Value

BACKGROUND AND OBJECTIVES: The presence of elevated troponin after percutaneous coronary intervention (PCI) is considered to reflect irreversible myocardial injury. However, its prognostic value remains unclear. The purpose of this study was to investigate the incidence, risk factors, and clinical outcomes of troponin I (TnI) elevation after the implantation of drug-eluting stent (DES). SUBJECTS AND METHODS: We performed a retrospective analysis of 335 patients who had undergone PCI with DES. Patients who had acute coronary syndrome with elevated TnI levels before PCI were excluded. TnI levels were measured 6 and 24 hours after PCI. RESULTS: Baseline clinical characteristics were similar in the elevated TnI and normal TnI groups. Elevated postprocedural TnI (>1.5 ng/mL) occurred in 52 patients (15.5%). Univariate analysis revealed that the clinically significant variables were multi-vessel disease (p<0.001), multiple stent implantation (p=0.003), total stent length (p=0.001), side-branch occlusion (p<0.001), and bifurcation lesion (p=0.003). Multivariate analysis indicated that the independent predictors of elevated TnI after DES implantation were multi-vessel disease (p=0.019), side-branch occlusion (p=0.001), and bifurcation (p=0.011). There were no significant differences in major adverse cardiovascular events between the elevated TnI and normal TnI groups (p=0.461). CONCLUSION: Multi-vessel disease, side-branch occlusion, and bifurcation were independent predictors of elevated TnI following DES implantation. The elevation of TnI after successful PCI with DES was not associated with worse 400-day clinical outcomes.