Administration of eptifibatide to acute coronary syndrome patients receiving enoxaparin or unfractionated heparin: effect on platelet function and thrombus formation.
OBJECTIVE
The goal of this study was to compare the antithrombotic effects of enoxaparin versus unfractionated heparin (UFH) when combined with eptifibatide in acute coronary syndrome (ACS) patients.


BACKGROUND
An increasing number of high-risk ACS patients are treated with low-molecular-weight heparin and a glycoprotein (GP) IIb/IIIa inhibitor. There is a paucity of data regarding the antithrombotic properties of such a combination as compared with UFH and GP IIb/IIIa inhibitors.


METHODS
Twenty-six ACS patients scheduled to undergo coronary angiography were treated with subcutaneous enoxaparin (n = 13) or intravenous UFH (n = 13). All patients received eptifibatide just before coronary angiography. Antithrombotic effects were assessed as changes in platelet-thrombus formation using the Badimon ex vivo perfusion chamber. Perfusions were carried out at a high shear rate (HSR) and a low shear rate (LSR). Patients underwent two perfusion studies: at baseline (under enoxaparin or UFH) and 10 min after the eptifibatide bolus. Platelet function was evaluated by ADP-induced platelet aggregation and the rapid platelet function analyzer.


RESULTS
Both therapeutic combinations achieved a marked reduction in platelet aggregation after eptifibatide (83% to 89.7% reduction in the enoxaparin-eptifibatide group and 77.8% to 85.5% reduction in the UFH-eptifibatide group, inter-group differences not significant). Both groups also demonstrated marked reductions in thrombus formation, but the reductions achieved in the enoxaparin-eptifibatide group were significantly higher than those achieved in the UFH-eptifibatide group (HSR: 75.6% reduction vs. 63.9%, respectively, p = 0.01; LSR: 79.7% reduction vs. 66.1%, respectively, p = 0.0001).


CONCLUSIONS
The combination of eptifibatide with enoxaparin appears to have a more potent antithrombotic effect than that of eptifibatide and UFH in the doses tested.
Lev
Eli I
EI
Cardiology Department, Rabin Medical Center, 39 Jabotinski Street, Petah-Tikva 49100, Israel.
Hasdai
David
D
Scapa
Erez
E
Tobar
Ana
A
Assali
Abid
A
Lahav
Judith
J
Battler
Alexander
A
Badimon
Juan J
JJ
Kornowski
Ran
R
D000925:Anticoagulants / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D001772:Blood Cell Count; D017023:Coronary Angiography; D004359:Drug Therapy, Combination; D017984:Enoxaparin / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D000077542:Eptifibatide; D005260:Female; D006493:Heparin / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D010314:Partial Thromboplastin Time; D010455:Peptides / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors*; D016896:Treatment Outcome; D020246:Venous Thrombosis / Q000517:prevention & control
D000925:Anticoagulants; D017984:Enoxaparin; D010455:Peptides; D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D006493:Heparin; D000077542:Eptifibatide