The emerging role of platelet glycoprotein IIb/IIIa inhibitors in managing high-risk patients with non-ST segment elevation acute coronary syndromes.
BACKGROUND
Current practice guidelines recommend administering a platelet glycoprotein IIb/IIIa inhibitor, in conjunction with aspirin and heparin, for patients with non-ST segment elevation (NSTE) acute coronary syndromes (ACS) for whom an early invasive management strategy is planned. However, optimal timing of glycoprotein IIb/IIIa inhibitor administration - 'upstream' in the coronary care unit or 'downstream' when the patient goes to the catheterization laboratory - has not been established.


METHODS
This paper evaluates recent trial results that help to better define the role of platelet glycoprotein IIb/IIIa inhibitors for treating high-risk patients with NSTE ACS who are scheduled for percutaneous coronary intervention (PCI). The Medline database was searched in February 2007 to retrieve relevant articles. Additional articles were obtained from the reference lists of retrieved articles, as well as from recent scientific meetings and company websites.


RESULTS
Results of the ISAR-REACT 2 trial indicate that administration of abciximab provides significant benefit for high-risk patients with NSTE ACS undergoing PCI; clopidogrel alone is not enough. In preliminary results of the ACUITY trial, glycoprotein IIb/IIIa inhibitor administration produced an incremental increase in bleeding events but a reduction in ischemic events; there was a trend to better outcomes with upstream administration, even short-term. Moreover, in the cohort of patients who underwent PCI, the composite ischemic endpoint was significantly lower with routine upstream glycoprotein IIb/IIIa inhibitor. Finally, results of the EVEREST pilot study, a mechanistic study evaluating epicardial and tissue level perfusion and cardiac troponin I release, significantly favored upstream administration of tirofiban over downstream glycoprotein IIb/IIIa inhibitor for high-risk patients with NSTE ACS undergoing PCI. Moreover, high bolus dose tirofiban or abciximab administered just before PCI produced similar effects on angiographic outcome and cardiac troponin I release.


CONCLUSIONS
Recent and emerging evidence is clarifying the role of glycoprotein IIb/IIIa inhibitors in treating high-risk patients with NSTE ACS and indicates that these agents are of greatest benefit when given early.
Bolognese
Leonardo
L
Cardiovascular Department, Department of Cardiovascular Disease, Azienda Ospedaliera, Arezzo, Italy. leonardobolognese@hotmail.com
D054058:Acute Coronary Syndrome / Q000188:drug therapy*; D002986:Clinical Trials as Topic; D004358:Drug Therapy / Q000639:trends; D006801:Humans; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors*; D017410:Practice Guidelines as Topic; D012307:Risk Factors
D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex