Impact of bivalirudin or unfractionated heparin on platelet aggregation in patients pretreated with 600 mg clopidogrel undergoing elective percutaneous coronary intervention.
OBJECTIVE
The aim of this study was to assess the impact of bivalirudin or unfractionated heparin (UFH) on platelet aggregation in patients, pretreated with a 600 mg loading dose clopidogrel, undergoing elective percutaneous coronary intervention (PCI).


RESULTS
Patients (n = 100) were recruited consecutively in the setting of a double-blind, randomized trial. Bivalirudin or UFH was administered during PCI. Blood was drawn immediately before PCI, following administration of bivalirudin or UFH directly after PCI, and 24 h after PCI. Adenosine diphosphate (ADP)-induced platelet aggregation was assessed with light transmission aggregometry (LTA) and multiple electrode aggregometry (MEA). Before PCI, ADP-induced platelet aggregation was similar in UFH and bivalirudin patients (P = 0.99 for LTA; P = 0.28 for MEA). Administration of bivalirudin during PCI resulted in significant additional suppression of platelet aggregation (P = 0.012 for LTA; P = 0.008 for MEA). Administration of UFH did not have a significant influence on platelet aggregation (P = 0.42 for LTA; P = 0.78 for MEA). Platelet aggregation was again similar in the two groups 24 h after PCI (P > 0.05 for LTA and MEA).


CONCLUSIONS
Bivalirudin, given during PCI in patients pretreated with 600 mg of clopidogrel, is in contrast to UFH associated with further inhibition of platelet aggregation.
Sibbing
Dirk
D
Deutsches Herzzentrum and 1. Medizinische Klinik rechts der Isar, Technische Universität München, Munich, Germany.
Busch
Gabriele
G
Braun
Siegmund
S
Jawansky
Stefan
S
Schömig
Albert
A
Kastrati
Adnan
A
Ott
Ilka
I
von Beckerath
Nicolas
N
D000244:Adenosine Diphosphate / Q000378:metabolism; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D000925:Anticoagulants / Q000008:administration & dosage*; D000077144:Clopidogrel; D004311:Double-Blind Method; D005260:Female; D006493:Heparin / Q000008:administration & dosage; D006629:Hirudins / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D010446:Peptide Fragments / Q000008:administration & dosage*; D019990:Perioperative Care; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage*; D010979:Platelet Function Tests / Q000379:methods; D011292:Premedication; D011994:Recombinant Proteins / Q000008:administration & dosage; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives
D000925:Anticoagulants; D006629:Hirudins; D010446:Peptide Fragments; D010975:Platelet Aggregation Inhibitors; D011994:Recombinant Proteins; D000244:Adenosine Diphosphate; D006493:Heparin; D000077144:Clopidogrel; D013988:Ticlopidine; C074619:bivalirudin