Justification of 150 mg clopidogrel in patients with high on-clopidogrel platelet reactivity.
Eur J Clin Invest
; 42(4): 384-92, 2012 Apr.
Article
in En
| MEDLINE
| ID: mdl-21902692
ABSTRACT
BACKGROUND:
The GRAVITAS trial showed that 150 mg clopidogrel did not improve outcome in patients with high on-clopidogrel platelet reactivity (HPR) screened by the VerifyNow assay. We aimed to determine the impact of 150 mg clopidogrel in stable angina patients with HPR identified with conventional aggregometry (LTA). MATERIALS ANDMETHODS:
Clopidogrel-naive stable angina patients before ad hoc percutaneous coronary intervention were recruited into a randomized, double-blind, placebo-controlled trial (NCT00638326). Twelve to 24 h after the 600-mg loading dose of clopidogrel, ADP(5µM)-stimulated maximal (AGGmax), late platelet aggregation (AGGlate) and vasodilator-stimulated phosphoprotein phosphorylation (VASP-PRI) were evaluated. Patients with HPR (AGGmax ≥ 34%) were randomly allocated to 75 or 150 mg clopidogrel after 4 weeks. After control platelet function measurements at day 28, 75 mg clopidogrel was administered to all patients until 1 year.RESULTS:
The study was prematurely terminated at the stage of 200 enroled patients. Administration of 150 mg clopidogrel significantly reduced platelet aggregation (AGGmax 45·0 ± 6·8 vs. 33·8 ± 15·1, P < 0·01; AGGlate 27·1 ± 14·7 vs. 13·8 ± 18·0, P < 0·01) and VASP-PRI (57·5 ± 15·2 vs. 37·2 ± 17·1; P < 0·01), while platelet reactivity remained unchanged in patients with HPR receiving 75 mg clopidogrel. The higher maintenance dose of clopidogrel was associated with a significant reduction in cardiovascular (CV) death and myocardial infarction (MI) (0% vs. 11·4%, P = 0·04) and in CV death, MI or target vessel revascularization (24·6% vs. 3·1%; P = 0·01) during 1 year.CONCLUSIONS:
One-month administration of 150 mg maintenance dose of clopidogrel reduces platelet reactivity and might decrease the risk of thrombo-ischaemic complications in stable angina patients with HPR identified by LTA.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Phosphoproteins
/
Blood Platelets
/
Ticlopidine
/
Platelet Aggregation Inhibitors
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Cell Adhesion Molecules
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Platelet Aggregation
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Angina, Stable
/
Microfilament Proteins
Type of study:
Clinical_trials
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Eur J Clin Invest
Year:
2012
Type:
Article
Affiliation country:
Hungary