Aborted myocardial infarction in intracoronary compared with standard intravenous abciximab administration in patients undergoing primary percutaneous coronary intervention for ST-elevation myocardial infarction

Backgound: Abciximab reduces major adverse cardiac events (MACEs) in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Intracoronary (IC) abciximab bolus application might be more effective than a standard intravenous (IV) bolus. So far the occurrence of aborted MI, a new therapeutic target of effective treatment in STEMI, has not been evaluated in IC versus IV abciximab administration in STEMI patients undergoing primary PCI. Methods: To investigate the extent of aborted MI, 154 patients undergoing primary PCI were randomized to either IC (n = 77) or IV (n = 77) bolus abciximab administration with subsequent 12-hour intravenous infusion. For assessment of infarct size and extent of microvascular obstruction, all patients underwent late enhancement magnetic resonance imaging (MRI). Aborted MI was defined by major (≥ 50%) ST-segment resolution and a lack of subsequent cardiac enzyme rise ≥ 2 the upper normal limit. We also assessed the occurrence of true aborted MI defined as the absence of myocardial necrosis in MRI. Results: The incidence of aborted MI was significantly higher in the IC group (p = 0.04); true aborted MI was only observed in the IC abciximab group (p = 0.01). At multivariable logistic regression analysis, IC abciximab application was a significant independent predictor of true aborted MI (p = 0.03). Aborted MI patients had an excellent prognosis at 6-month follow-up with no MACE as compared to 24 events in patients with non-aborted MI. Conclusions: IC bolus application of abciximab in STEMI patients undergoing primary PCI results in a higher incidence of aborted MI and subsequent improved clinical outcome.