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Platelet activation and coronary stent implantation. Effect of antithrombotic therapy
1First Medizinische Klinik, Technischen Universität München, Germany.
Insights
Ticlopidine and aspirin therapy effectively reduces platelet activation after coronary stenting, unlike anticoagulation. This antiplatelet approach may lower subacute stent thrombosis incidence.
Area of Science:
- Cardiology
- Hematology
- Pharmacology
Background:
- Platelet activation and glycoprotein expression are crucial in post-coronary intervention thrombotic events.
- Understanding antithrombotic effects on platelet function is vital for preventing complications.
Purpose of the Study:
- To compare the impact of ticlopidine plus aspirin versus conventional anticoagulation on platelet function post-coronary stent implantation.
- To evaluate specific markers of platelet activation and deactivation.
Main Methods:
- A case-control study involving patients undergoing coronary Palmaz-Schatz stent implantation.
- Platelet function was assessed using immunologic markers (LIBS1, CD62P) before and after stenting.
- Patients were treated with either ticlopidine (250 mg BID) + aspirin (100 mg BID) or conventional anticoagulation (phenprocoumon, heparin, aspirin).
Main Results:
- Anticoagulation therapy significantly increased surface exposure of LIBS1 and CD62P post-stenting.
- Ticlopidine-aspirin treatment led to decreased LIBS1 expression and unchanged CD62P levels.
- Platelet count decreased with anticoagulation but remained stable with ticlopidine-aspirin.
Conclusions:
- Conventional anticoagulation therapy promotes significant platelet activation after stenting.
- Combined antiplatelet therapy (ticlopidine + aspirin) induces platelet deactivation.
- These findings suggest a potential reduction in subacute stent thrombosis with antiplatelet therapy.
Background:
Platelet activation and surface expression of adhesive glycoproteins play a key role in ischemic thrombotic complications after coronary intervention. The purpose of this case-control study was to evaluate the effects of two different antithrombotic regimens on platelet function after coronary Palmaz-Schatz stent implantation.
Methods And Results:
The study group consisted of 46 "low-risk" patients who were treated with ticlopidine (250 mg BID) and aspirin (100 mg BID) after stenting. The control group was derived from a cohort of 151 patients receiving conventional anticoagulation therapy, including phenprocoumon (target international normalized ratio, 3.5), heparin (activated partial thromboplastin time, 80 to 120 seconds), and aspirin (100 mg BID) after stenting. Criteria for matching were indication for stenting, target vessel, balloon size, inflation pressure, and number of inserted stents. Matches were obtained for 38 patients. Platelet function was evaluated before and daily for 12 days after stenting in venous blood samples with immunologic activation markers. Patients receiving anticoagulation therapy showed a significantly increased surface exposure of LIBS1 (activated fibrinogen receptor; P < .05) and CD62P (P-selectin; P < .001) above prestent values, peaking days 3 to 6 after stenting. In contrast, in patients receiving ticlopidine, expression of LIBS1 decreased (P < .01) and expression of CD62P remained basically unchanged after stenting. Platelet count significantly decreased after stenting in patients treated by anticoagulation (day 3; P < .01), whereas no significant changes were found in the ticlopidine group.
Conclusions:
Significant platelet activation occurs in patients receiving anticoagulation therapy after stenting, while platelet deactivation is found in patients treated with combined antiplatelet therapy. This may contribute to a lowering of the incidence of subacute stent thrombosis.