Abstract 6: Temporal Shifts in Antithrombotic Therapy Help Explain Reduction in Bleeding Complications Among Patients Undergoing Percutaneous Coronary Intervention: Results from an NCDR® Report

Background Though studies suggest post-PCI bleeding has decreased over time, the factors associated with this temporal reduction remain unclear. Methods Using the CathPCI Registry®, we examined temporal trends in bleeding between 2005-2009 in elective PCI (E-PCI) (n=599,524), UA/NSTEMI (n=836,103), and STEMI (n=267,632). We quantified the linear time trend in bleeding using three sequential logistic regression models: (Model 1) Clinical factors associated with PCI bleeding; (Model 2) Model 1 + vascular access strategies(femoral vs. radial, closure devices); (Model 3) Model 2 + anticoagulation treatments (anticoagulation ± GP 2b/3a). Changes in the adj. OR for time trend were then compared. Table illustrates changes in expected annual bleeding events using 2005 event rates as reference (n=1375 bleeds in E-PCI, n=3327 in UA/NSTEMI, n=1978 in STEMI). Results Between 2005-2009, there was an approximate 20% decline in PCI bleeding: absolute crude change for E-PCI (1.4% to 1.1%), for UA/NSTEMI (2.3% to 1.8%), for STEMI (4.9% to 4.5%). In this period, vascular access via radial remained low (<3%) and closure devices use was steady (45-50%). In contrast, bivalirudin use increased from 17% to 30%, while heparin + GP2b/3a decreased from 41% to 28%. After adjusting for clinical variables, there was a 6-8% per year reduction in adj OR of bleeding for E-PCI & UA/NSTEMI (Table). While there was only a small reduction in bleeds per year after adjusting for changes in vascular access strategies, adjusting for antithrombotic strategies accounted for nearly half of the temporal annual reduction in bleeding (Table): from 97 to 48 expected bleeds per year for E-PCI, 164 to 95 in UA/NSTEMI, and 49 to 23 in STEMI. Conclusion There has been a modest temporal reduction in post-PCI risk of bleeding. Nearly half of this reduction can be attributable to changes in antithrombotic choices. Adoption of the radial approach, combined with pharmacological strategies, may further reduce bleeding. View this table: