AHA: Abciximab Straight to Heart No Help in PCI
By Crystal Phend, Senior Staff Writer,
November 14, 2011
Action Points
Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
Note that this large, randomized trial indicates that the intracoronary administration of abciximab, although safe, is not associated with measurable outcome benefits compared to the standard IV bolus.
Review
ORLANDO -- Injecting the glycoprotein IIb/IIIa inhibitor abciximab (ReoPro) directly into the heart during percutaneous coronary intervention (PCI) doesn't boost the agent's benefits, researchers found.
The intracoronary approach to bolus administration appeared safe for myocardial infarction (MI) patients in the AIDA STEMI trial, Holger Thiele, MD, of the University of Leipzig Heart Center in Leipzig, Germany, reported here at the American Heart Association meeting.
But the rate of death, reinfarction, and new onset congestive heart failure was similar for intracoronary and intravenous administration at 7% compared with 7.6% (P=0.58).
The only significant advantage of intracoronary administration was lower incidence of heart failure as an individual outcome (2.4% versus 4.1%, P=0.04).
"However, this might be an effect of chance," Thiele said at an AHA press conference where he presented the late-breaking clinical trial results.
The heart failure curves diverged rapidly and maintained their separation for the duration of the trial.
But Thiele noted that his group could not confirm that ST-segment MI resolution or infarct size, as assessed indirectly by the release of creatine kinase, was any different between groups (P=0.37 and P=0.74, respectively).
While guidelines from the AHA and other organizations suggest the intracoronary route may be reasonable, IV administration should remain the standard of care for abciximab, said study discussant Alice Jacobs, MD, of Boston Medical Center.
"There should be no change in clinical practice," she said.
The study included 2,065 patients in Germany undergoing PCI for suspected STEMI, who were randomized to receive a 0.25 mg/kg bolus of abciximab via IV or intracoronary infusion, both followed by a 12 hour IV infusion at 0.125 μg/kg per minute.
But a lower than expected event rate meant the trial was somewhat underpowered and could not exclude a small to moderate difference in outcome between the two arms, although that was unlikely looking just at the absolute numbers, Jacobs noted.
Mortality rates were 4.5% in the intracoronary group versus 3.6% in the IV group (P=0.36). Reinfarction rates were 1.8% in both groups.
The only subgroup that appeared to derive greater benefit from abciximab when given as an intracoronary infusion was women.
"Whether the lack of difference in outcome is due to the lower risk patients with lower event rate; a more rapid distribution of IV abciximab, which we know does occur; or the background of dual-antiplatelet therapy remains unclear," Thiele said.
The safety too was similar between intracoronary and IV groups:
In-hospital stroke (0.5% versus 0.7%, P=0.70)
Stent thrombosis (1.7% versus 2%, P=0.65)
Severe, moderate, and mild bleeding events by GUSTO trial criteria (2.6% versus 1.8%, 2.6% for both, and 8% versus 8.5%, respectively; P=0.63)
Hemodynamic compromise during abciximab bolus (0.1% versus 0.6%, P=0.06)
Life-threatening arrhythmia during PCI (1.7% versus 2.1%, P=0.22)
Further studies might still look at intracoronary abciximab for patients with large infarcts and thrombus burden or no reflow, Jacobs suggested.