Selecting and managing anticoagulation in patients with acute coronary syndrome (ACS) is a multifaceted, complicated issue; the individual variations in dosage requirements make over-anticoagulation a common problem. Recently, the REG1 anticoagulation system was evaluated for its ability to control bleeding with an early invasive approach, but the feasibility of using the REG1 system to prevent ischemic events has not been well studied.

In a report appearing in the European Heart Journal, Thomas J. Povsic, MD, PhD, from Duke University Medical Center, and colleagues sought to determine the safety of this strategy, as well as the degree of anticoagulation reversal required to mitigate bleeding in ACS patients.

Povsic et al., on behalf of the RADAR investigators, randomized 640 non-ST-elevation ACS (NSTE-ACS) patients with planned early cardiac catheterization via femoral access to one of five groups: REG1 system with 25, 50, 75, or 100% anivamersen reversal or heparin. The REG1 anticoagulation system consists of pegnivacogin—an RNA aptamer selective factor IXa inhibitor—and its complementary controlling agent, anivamersen.

Major bleeding events were less common, but still significant. Secondary endpoints (including major bleeding and the composite of death, MI, urgent target vessel revascularization, or recurrent ischemia) were also controlled with use of the REG1 anticoagulation system: 3.0% of REG1 patients and 5.7% of heparin patients experienced ischemic events.

Of note, enrollment in the 25% reversal arm was suspended early at 41 patients, after three patients experienced allergic-like reactions.

As shown by their findings, "REG1 appears [to be] a safe strategy to anticoagulate ACS patients managed invasively and warrants further investigation in adequately powered clinical trials of patients who require short-term high-intensity anticoagulation," the investigators concluded. Furthermore, at least 50% reversal is required to allow safe removal of the sheath after cardiac catheterization, suggesting that near complete inhibition of factor IXa with the REG1 strategy allows for effective periprocedural anticoagulation without increased bleeding risk.

---

Povsic TJ, Vavalle JP, Aberle LH, et al. Eur Heart J. 2013 July 22. [Epub ahead of print]

Keywords: Aptamers, Nucleotide, Acute Coronary Syndrome, Cardiac Catheterization, Heparin

< Back to Listings