OBJECTIVES: We investigated whether maintenance therapy with clopidogrel 150 mg/day produces greater platelet inhibition than the standard 75-mg/day dose and whether the higher maintenance dose increases platelet inhibition in low responders to clopidogrel 75 mg/day. BACKGROUND: Patients show interindividual variability in their platelet response to clopidogrel. Low responders could potentially obtain greater clinical benefit from greater doses of clopidogrel. METHODS:One hundred fifty-three elective percutaneous coronary intervention patients were randomized to clopidogrel 150 mg/day (n = 58) or 75 mg/day (n = 95) for 4 weeks, with vasodilator-stimulated phosphoprotein assay-guided switching to clopidogrel 150 mg/day after 2 weeks in low responders (platelet reactivity index >or=69%). All patients received aspirin 75 mg/day. RESULTS: After 2 weeks, clopidogrel 150 mg/day produced a significantly lower platelet reactivity index than clopidogrel 75 mg/day (43.9 +/- 17.3% vs. 58.6 +/- 17.7%; p < 0.0001). The proportion of low responders was significantly lower in patients randomized to clopidogrel 150 mg/day than in those randomized to clopidogrel 75 mg/day (8.6% vs. 33.7%; p = 0.0004). In the clopidogrel 75 mg/day group, 64.5% (20 of 31) of low responders became responders after switching to clopidogrel 150 mg/day for 2 weeks. No major bleeds occurred during the study; the incidence of minor bleeds was similar in each treatment group. CONCLUSIONS: In elective percutaneous coronary intervention patients, a 150-mg/day clopidogrel maintenance dose produces greater inhibition of platelet function than clopidogrel 75 mg/day. In low responders to clopidogrel 75 mg/day, switching to clopidogrel 150 mg/day overcomes low responsiveness in a majority of patients. These findings warrant further clinical evaluation. (VASP-02; EudraCT number: 2004-005230-40).
RCT Entities:
OBJECTIVES: We investigated whether maintenance therapy with clopidogrel 150 mg/day produces greater platelet inhibition than the standard 75-mg/day dose and whether the higher maintenance dose increases platelet inhibition in low responders to clopidogrel 75 mg/day. BACKGROUND:Patients show interindividual variability in their platelet response to clopidogrel. Low responders could potentially obtain greater clinical benefit from greater doses of clopidogrel. METHODS: One hundred fifty-three elective percutaneous coronary intervention patients were randomized to clopidogrel 150 mg/day (n = 58) or 75 mg/day (n = 95) for 4 weeks, with vasodilator-stimulated phosphoprotein assay-guided switching to clopidogrel 150 mg/day after 2 weeks in low responders (platelet reactivity index >or=69%). All patients received aspirin 75 mg/day. RESULTS: After 2 weeks, clopidogrel 150 mg/day produced a significantly lower platelet reactivity index than clopidogrel 75 mg/day (43.9 +/- 17.3% vs. 58.6 +/- 17.7%; p < 0.0001). The proportion of low responders was significantly lower in patients randomized to clopidogrel 150 mg/day than in those randomized to clopidogrel 75 mg/day (8.6% vs. 33.7%; p = 0.0004). In the clopidogrel 75 mg/day group, 64.5% (20 of 31) of low responders became responders after switching to clopidogrel 150 mg/day for 2 weeks. No major bleeds occurred during the study; the incidence of minor bleeds was similar in each treatment group. CONCLUSIONS: In elective percutaneous coronary intervention patients, a 150-mg/day clopidogrel maintenance dose produces greater inhibition of platelet function than clopidogrel 75 mg/day. In low responders to clopidogrel 75 mg/day, switching to clopidogrel 150 mg/day overcomes low responsiveness in a majority of patients. These findings warrant further clinical evaluation. (VASP-02; EudraCT number: 2004-005230-40).
Authors: Gunnar Tepe; Rüdiger Bantleon; Klaus Brechtel; Jörg Schmehl; Thomas Zeller; Claus D Claussen; Frederik F Strobl Journal: Eur Radiol Date: 2012-05-10 Impact factor: 5.315