Platelet Aggregation and Recruitment with Aspirin-Clopidogrel Therapy

Abstract

Background: Aspirin-clopidogrel combination therapy inhibits platelet aggregation. The effect on platelet recruitment is unknown. Methods: Thirty chronic ischemic stroke patients taking aspirin alone followed by aspirin-clopidogrel combined therapy had platelet reactivity tests performed over 3 months: ex vivo platelet aggregation, platelet recruitment and urinary 11-dehydro-thromboxane B₂ (11-dhTxB₂)excretion. Statistical analysis of variance compared platelet aggregation and recruitment between aspirin alone and aspirin-clopidogrel, and longitudinal regression analysis estimated platelet recruitment over time. Nonlinear mapping defined variable connections in each patient. Results: Statistically significant differences were found between aspirin alone and aspirin-clopidogrel for (1) adenosine-diphosphate- and collagen-induced platelet aggregation and maximum inhibition of platelet recruitment and (2) increasing inhibition of platelet recruitment over time. Urinary 11-dhTxB₂ excretion did not predict platelet aggregation response. Nonlinear mapping showed patient-unique variable interconnections. Conclusions: Platelet inhibition with aspirin-clopidogrel may increase over time, and future studies should focus on this finding in the context of vascular complications.

Effect of clopidogrel treatment on stress-induced platelet activation and myocardial ischemia in aspirin-treated patients with stable coronary artery disease

“…This may be due to already low thromboxane generation in healthy subjects in contrast to patients with manifest vascular disease where thromboxane generation is increased [4,55]. However, Helgasson et al had similar negative findings as ours in a study in 30 chronic ischemic stroke patients treated with aspirin and clopidogrel [226]. It has recently been proposed that aspirin may provide little additional protection against athero-thrombotic events in presence of strong P2Y 12 receptor blockade [227], but this is speculative since no large study has investigated the effect of adding aspirin or placebo to clopidogrel treatment in patients with CAD.…”

Aspirin plus Clopidogrel as Secondary Prevention after Stroke or Transient Ischemic Attack: A Systematic Review and Meta-Analysis

“…1) [10,12,13,14,15,22,23,24]. A total of 18 studies were excluded: four were excluded because they were not RCTs [25,26,27,28], three were excluded because the comparator was not aspirin or clopidogrel alone [29,30,31], seven were excluded for lack of specific data [9,32,33,34,35,36,37], two were excluded since the trials were ongoing [38,39], and two were excluded due to redundancy [40,41]: the original study reported both primary and secondary prevention, and the subsequent report [14] focused on results in patients with previous TIA or ischemic stroke. The baseline characteristics of included studies are summarized in table 1.…”

The single individual in medicine: how to escape from the probability theory trap

“…PST carries out this type of projection by means of an evolutionary algorithm called GenD [ 3 ], specifically defined to achieve this aim. Pilot experiences in medicine are already available and seem quite encouraging [ 4 , 5 ].…”