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Published on: February 26, 2013

[Thrombocyte aggregation in patients with cardiac arrhythmias and effect of anti-arrhythmia agents]

R D Kurbanov, N A Azimova, G K Kiakbaev

    Kardiologiia
    |January 1, 1993
    PubMed

    Insights

    Platelet aggregation is higher in myocardial infarction patients with frequent ventricular extrasystoles (VE). Certain antiarrhythmic drugs like ethacizine and cordarone inhibit platelet activity, but in vitro results differ from in vivo findings.

    Area of Science:

    • Cardiology
    • Pharmacology
    • Hematology

    Background:

    • Patients with prior myocardial infarction (MI) often develop cardiac arrhythmias.
    • Platelet hyperactivity is a significant risk factor for thrombotic events in MI patients.
    • The impact of antiarrhythmic drugs on platelet function in this cohort is not fully understood.

    Purpose of the Study:

    • To investigate platelet aggregability in patients with MI and various cardiac arrhythmias.
    • To evaluate the effects of specific antiarrhythmic agents on platelet function.
    • To compare in vitro and in vivo antiplatelet effects of these agents.

    Main Methods:

    • Studied 81 patients with prior MI and different cardiac arrhythmias.
    • Assessed platelet aggregability in patients with frequent ventricular extrasystoles (VE) and high-grade VE (Lown grades 4a, 4b) versus controls.
    • Administered and evaluated the effects of allapinine, ethacizine, obsidan, and cordarone on platelet activity.

    Main Results:

    • Platelet aggregability was 32-39% higher in patients with frequent and high-grade VE compared to controls and those with supraventricular or rare VE.
    • Ethacizine and cordarone significantly inhibited platelet functional activity.
    • Allapinine and obsidan showed insignificant effects on platelet aggregability.
    • No correlation was found between the antiarrhythmic efficacy and antiaggregatory properties of the drugs.
    • In vitro and in vivo results regarding drug effects on platelet aggregability were discordant.

    Conclusions:

    • Frequent and high-grade ventricular extrasystoles in MI patients are associated with increased platelet aggregability.
    • Ethacizine and cordarone demonstrate significant antiplatelet activity.
    • The antiarrhythmic and antiplatelet effects of these drugs are not directly correlated.
    • Discordance between in vitro and in vivo assessments of antiplatelet effects highlights the complexity of drug evaluation in this context.

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