Recent studies suggest that anti-platelet agents are not equally effective in all individuals. We have developed a new method to evaluate the effect of anti-platelet drugs using the cone and plate(let) analyzer (CPA) test. The method is based on the ability of activators to reduce platelet adhesion under flow conditions. Treatment of a blood sample with arachidonic acid (AA) or ADP in vitro significantly decreased platelet deposition to a surface coverage (SC) of 2.1 ± 0.4 and 1.3 ± 0.6%, respectively, compared with the basic SC of 12.3± 6.8%. The effect of AA was prevented by aspirin (SC 8.1 ± 3.8%) and that of ADP was reduced by 2-methylthio-AMP, a P2Y12 ADP receptor inhibitor (SC 4.8 ± 2.0%). Pre-incubation with AA of whole blood samples from untreated healthy volunteers resulted in a marked decline of SC (from SC 9.8 ± 2.2 to 0.6 ± 0.3%). In contrast, in volunteers treated with 100, 300, and 500 mg aspirin per day, AA (but not ADP) decreased SC only to 3.5± 1.3, 4.4 ± 1.7, and 4.1 ± 2.0%, respectively (P < 0.001 versus SC with AA before treatment). A good correlation was observed between the modified CPA and aggregometry (R2 = 0.55). In conclusion, the modified CPA test is a useful tool to evaluate the efficacy of anti-platelet therapy.
- Anti-platelet drugs
- Cone and Plate(let) analyzer