Administering the platelet inhibitor abciximab directly into a blocked coronary artery was no more effective than intravenous delivery in improving overall health outcomes in severe heart attack patients, according to late-breaking research presented at the American Heart Association's Scientific Sessions 2011.

In the Intracoronary Compared with Intravenous Bolus Abciximab Application During Primary Percutaneous Coronary Intervention (AIDA STEMI) Trial, researchers tested whether administering a dose of the anti-platelet agent abciximab into the blocked coronary artery (intracoronary) route, instead of the standard intravenous route, would improve outcomes for patients undergoing percutaneous coronary intervention (PCI).

Patients in the study had suffered an ST-elevation myocardial infarction (STEMI).

Researchers randomized 2,065 STEMI patients undergoing PCI at 22 hospitals from July 2008 to April 2011 to receive abciximab by an IV infusion or directly into the blocked artery. Within 90 days, 7 percent of those receiving the direct administration died, had another heart attack or developed new heart failure, compared to 7.6 percent of those receiving the intravenous route.

"Neither therapy arm was superior to the other in the primary endpoint," said Holger Thiele, M.D., lead researcher of the study and deputy director of the Department of Internal Medicine/Cardiology at the University of Leipzig - Heart Center in Germany. "However, we found a lower rate of heart failure in the intracoronary patients."

Only 2.4 percent (22 of 935) patients receiving the intracoronary dose were diagnosed with heart failure within 90 days, compared to 4.1 percent, or 38 of the 932 patients, receiving the intravenous dose, (P=0.04), a statistically significant difference.

Research had suggested that the intracoronary delivery during PCI could boost concentration of the drug at the treatment site, limit heart tissue destruction and improve blood flow. But researchers found no difference between the two study groups in blood flow or infarct size.

"Intracoronary administration of abciximab is safe, with no significant increase in bleeding or other problems," Thiele said.

Co-authors are Jochen Wöhrle, M.D.; Rainer Hambrecht, M.D.; Harald Rittger, M.D.; Ralf Birkemeyer, M.D.; Bernward Lauer, M.D.; Petra Neuhaus, Ph.D.; Oana Brosteanu, Ph.D.; Peter Sick, M.D.; Marcus Wiemer, M.D.; Sebastian Kerber, M.D.; Klaus Kleinertz, M.D.; Ingo Eitel, M.D.; Steffen Desch, M.D.; and Gerhard Schuler, M.D.

The Heart Center and Clinical Trial Center at the University of Leipzig and the Bundesministerium für Bildung und Forschung (BMBF) in Germany funded the trial. Researchers also received an unrestricted grant from Lilly Germany.