Microfluidic thrombosis under multiple shear rates and antiplatelet therapy doses

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Pharmacology

Background:

• Thrombosis, a major cause of heart attack and stroke, is treated with antiplatelet therapy.
• Current antiplatelet therapy dosing and resistance are not well understood, leading to suboptimal treatment.
• The role of shear rate in thrombosis is suspected but has been difficult to study quantitatively.

Purpose of the Study:

• To quantitatively assess the effects of varying shear rates and antiplatelet drug concentrations on thrombosis.
• To compare the efficacy of different antiplatelet agents (eptifibatide, acetyl-salicylic acid, heparin) under different shear conditions.
• To provide data for optimizing antiplatelet therapy and understanding thrombosis mechanisms.

Main Methods:

• A microfluidic device was used to measure occlusion times and thrombus detachment under controlled shear rates (500-10000 s⁻¹).
• Multiple antiplatelet agents, including acetyl-salicylic acid (ASA) and eptifibatide, were tested at various concentrations.
• Complete blood counts and platelet activity were measured; statistical models analyzed shear rate and dose effects.

Main Results:

• Shear rates significantly influenced thrombosis dose-response curves for all tested therapies.
• Acetyl-salicylic acid (ASA) demonstrated minimal effect on high shear occlusion, even at supra-therapeutic doses.
• Eptifibatide reduced occlusion, with efficacy increasing with dose, while ASA showed a much higher occlusion hazard than eptifibatide.

Conclusions:

• High shear rates critically affect antiplatelet therapy efficacy, challenging current treatment paradigms.
• The study highlights limitations of ASA at high shear rates and suggests eptifibatide may be more effective in such conditions.
• This research provides a quantitative basis for improving thrombosis treatment models and patient care.