Changes of Whole Blood Platelet Function after Percutaneous Coronary Intervention with Stent Implantation

Antiplatelet agents are effective for improving the outcome of percutaneous coronary intervention (PCI) with stenting. The effects of PCI on platelet function have usually been investigated using platelet-rich plasma, which differs from the in vivo environment. In this study, we investigated the changes of whole blood platelet function after PCI with stenting, which have not been studied before. Methods: PCI with stenting was performed electively in 11 patients who were studied prospectively. Blood samples were drawn before the intervention, as well as 24, 48, and 72 hours after PCI. The same measurements were also done in 6 patients who received coronary angiography alone (controls). The platelet aggregatory threshold index (PATI) was measured using a new platelet aggregometer for whole blood. Results: The %PATI (= PATI follow up / PATI before the intervention ×100) showed a significant decrease at 48 hours when compared with before, at 24 and 72 hours (p<0.05). No significant changes of %PATI were seen in the controls. Conclusion: These findings suggest that efficacy of antiplatelet therapy should be tested at 48 hours after PCI with stenting.