High post-treatment platelet reactivity identified low-responders to dual antiplatelet therapy at increased risk of recurrent cardiovascular events after stenting for acute coronary syndrome.
OBJECTIVE
Low response to antiplatelet therapy may be a risk factor for the development of ischemic complications in patients with non-ST segment elevation acute coronary syndrome (NSTE ACS) undergoing coronary stenting.


METHODS
We prospectively studied the platelet response to both clopidogrel and aspirin in 106 NSTE ACS consecutive patients undergoing percutaneous coronary intervention (PCI) with stenting. A single post-treatment blood sample was obtained just before PCI and analyzed by platelet aggregometry using both ADP and arachidonic acid (AA) as agonists to explore the responses to clopidogrel and aspirin, respectively. Patients were divided into quartiles according to the ADP or AA induced maximal intensity of platelet aggregation. Patients of the highest quartile (quartile 4) were defined as the 'low-responders'.


RESULTS
Twelve recurrent cardiovascular (CV) events occurred during the 1-month follow-up. Clinical outcome was significantly associated with platelet response to clopidogrel [Quartile 4 vs. 1, 2, 3: OR (95% CI) 22.4 (4.6-109)]. Low platelet response to aspirin was significantly correlated with clopidogrel low response (P = 0.003) but contributed less to CV events [OR (95%CI): 5.76 (1.54-35.61)].


CONCLUSIONS
A post-treatment ADP-induced platelet aggregation performed just before PCI identifies low responders to dual antiplatelet therapy with an increased risk of recurrent CV events.
Cuisset
T
T
Department of Cardiology, CHU Timone, Marseille, France.
Frere
C
C
Quilici
J
J
Barbou
F
F
Morange
P E
PE
Hovasse
T
T
Bonnet
J-L
JL
Alessi
M-C
MC
D000208:Acute Disease; D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D001241:Aspirin / Q000494:pharmacology / Q000627:therapeutic use; D000077144:Clopidogrel; D003327:Coronary Disease / Q000209:etiology / Q000517:prevention & control* / Q000628:therapy; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D011292:Premedication; D011446:Prospective Studies; D012307:Risk Factors; D055502:Secondary Prevention; D015607:Stents / Q000009:adverse effects*; D013577:Syndrome; D013988:Ticlopidine / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D016896:Treatment Outcome
D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin