The nearly 20 percent reduction in post-PCI bleeding over time was largely due to temporal changes in antithrombotic strategies, according to a review of the National Cardiovascular Data CathPCI Registry published May 22 in the Journal of the American College of Cardiology. The authors summed that further reductions in bleeding complications may be possible as bleeding avoidance strategies evolve, especially in STEMI.

In this analysis, Sumeet Subherwal, MD, MBA, of the Duke Clinical Research Institute in Durham, N.C., and colleagues sought to examine the temporal trends in post- PCI bleeding among patients with elective PCI, unstable angina (UA)/non–STEMI [NSTEMI]) and STEMI because “it remains unclear to which extent bleeding avoidance strategies have been implemented in clinical practice.”

Using the CathPCI Registry, the researchers examined temporal trends in post-PCI bleeding from 2005 to 2009 among patients with elective PCI (599,524), UA/NSTEMI (836,103) and STEMI (267,632). They quantified the linear time trend in bleeding using three sequential logistic regression models:

1. Clinical factors;
2. Clinical plus vascular access strategies (femoral vs. radial, use of closure devices); and
3. Clinical, vascular strategies plus antithrombotic treatments (anticoagulant plus glycoprotein IIb/IIIa inhibitor [GPI]).  

The study authors found an approximate 20 percent reduction in post-PCI bleeding (elective PCI: from 1.4 percent to 1.1 percent; UA/NSTEMI: from 2.3 percent to 1.8 percent; STEMI: from 4.9 percent to 4.5 percent). Meanwhile, the radial approach remained low (less than 3 percent), and closure device use increased marginally from 44 to 49 percent.

Given that the use of radial artery access was "infrequent and did not change much over time, it is possible that the relative 10 percent to 13 percent increase in closure device utilization during the study accounted for the small, but significant, influence of vascular access strategies on reduction" in annual bleeding risk among the elective PCI and UA/NSTEMI groups.

“We found that vascular access strategies did not change much over this period, and thus, were minimally associated with these observed reductions in bleeding rates over time,” wrote Subherwal et al. “In contrast, there was a marked temporal change in concomitant antithrombotic strategy use during the study, which appeared to be associated with half of the reduction in risk of annual bleeding among elective PCI and UA/NSTEMI.”

Bivalirudin use increased (from 17 percent to 30 percent), while any heparin plus GPI use decreased (from 41 percent to 28 percent). There was a significant (from 6 percent to 8 percent) per year reduction in annual bleeding risk in UA/NSTEMI and elective PCI, but not in STEMI. Antithrombotic strategies were associated with roughly half of the reduction in annual bleeding risk: change in risk ratio from 7.5 percent to 4 percent for elective PCI, and from 5.7 percent to 2.8 percent for UA/NSTEMI.

In this analysis, the relative reduction in annual bleeding risks was noted to be in the elective PCI subgroup. “We did not find a significant temporal reduction in the STEMI population, which might be because patients with STEMI received more aggressive anticoagulation with thrombolytics (11.8 percent of STEMI population) and had greater use of intra-aortic balloon pumps (10 percent of STEMI population), both of which are associated with increased bleeding risk,” wrote Subherwal and colleagues. “The rate of bleeding in the STEMI subgroup was more than twice that of the UA/NSTEMI group and nearly four times that of the elective PCI group.”

Thus, the study authors concluded, “It remains to be seen whether further changes in vascular strategies—particularly increased adoption of transradial PCI, newer antithrombotics or both—will further reduce bleeding rates, particularly in the STEMI population. Future studies should continue to evaluate bleeding risk, as the landscape of antithrombotic therapies and use of bleeding avoidance strategies continues to evolve.”