035 Thrombectomy and platelet glycoprotein IIb/IIIa blockade for stent thrombosis

Abstract

Aims: Both mechanical thrombectomy and glycoprotein (GP) IIb/IIIa antagonists have been shown to improve clinical outcomes following primary percutaneous coronary intervention (PCI) for ST segment elevation myocardial infarction. There is limited data describing the use of these technologies in the setting of stent thrombosis. We aimed to assess the combined approach of mechanical thrombectomy with adjunctive GP IIb/ IIIa antagonists in patients presenting with acute stent thrombosis. Methods and results: This was an observational cohort study of 3040patients who underwent primary PCI at a single center between 2003 and 2011. The primary outcome was major adverse cardiac events (MACE, including all cause mortality, myocardial infarction, target vessel revascularisation and stroke). Follow-up was for a median of 3.0 years (IQR range 1.2-4.6 years). Patients were split into three groups: those who underwent PCI using mechanical thrombectomy and GP IIb/IIIa inhibitors, those receiving either GP IIb/IIIa inhibitor or mechanical thrombectomy, and those receiving neither. 201 patients (6.6%) with STEMI presented with stent thrombosis (ST). GP IIb/IIIa inhibitors were used in 176 (87.6%) and mechanical thrombectomy was used in 94 (46.7%). 88 (44%) patients received both GP IIb/IIIa inhibitors and thrombectomy, 92 (46%) received either GP IIb/IIIa inhibitor or thrombectomy and 21 (10%) received neither therapy. There were no significant differences in baseline characteristics between the three groups. Patients receiving both therapies tended to have more successful procedures, although this did not reach significance, and had significantly better post procedural left ventricular function (p=0.035). Kaplan-Meier estimates of long-term major adverse cardiac events showed the lowest rates of events for those patients receiving both therapies, followed by those receiving a single therapy, with the highest rates of MACE in those receiving neither therapy (34.4% [95% CI 14.1-46.0] vs. 66.6% [95% CI 56.6-76.7] vs. 80.7% [66.1-89.4], p<0.0001). All individual components of MACE were lower in those receiving both therapies. Age-adjusted Cox analysis showed a decrease in the hazard of death for those receiving both therapies compared to those receiving neither (hazard ratio 0.17 [95% CI 0.06-0.54]) and this was maintained with multiple adjustment (hazard ratio 0.11 [95% CI 0.02-0.85]). Conclusions: Prognosis after stent thrombosis is poor, with high long term event rates. Use of a combined approach of mechanical thrombectomy and adjunctive GP IIb/IIIa blockade leads to effective primary PCI with improved long-term outcomes. A randomised study is needed to clarify this benefit.