Effectiveness of antiplatelet therapy in atherosclerotic disease: comparing the ASA low-response prevalence in CVD, CAD and PAD

Abstract

Although acetylsalicylic acid (ASA, aspirin) reduces the risk of ischemic events in patients with atherosclerosis, a substantial number of incidents continue to occur. As only limited data exist we evaluated the antiplatelet effectiveness of ASA in patients with different manifestations of atherosclerosis as in cerebrovascular, coronary artery and peripheral arterial disease (CVD, CAD, PAD). For the evaluation of the antiplatelet effectiveness of ASA we used whole blood aggregometry (Chrono-log Model 590). The patients in the different subgroups received ASA 100, 200 or 500 mg daily. We analysed 737 consecutive patients: 47.5 % with CVD, 33.6 % with CAD, and 18.9 % with PAD. We identified 28.0 % of the CVD, 18.1 % of the CAD and 21.6 % of the PAD patients to be ASA low-responder (ALR). Comparing subgroups treated with 100 mg ASA, 36.4 % were ALR in the CVD group as were 13.1 % of the CAD and 21.6 % of the PAD patients. Multivariate regression analysis revealed an odds ratio for being ALR of 4.50 (95 % confidence interval (CI) 1.70-11.9) when 100 mg and of 2.97 (95 % CI 1.58-5.60) when 200 mg ASA was taken compared to a dose of 500 mg. Despite the proven benefits of antiplatelet therapy in the secondary prevention of atherosclerotic disease, current antiplatelet management is suboptimal as up to 36 % of patients failed to achieve an adequate platelet inhibitory effect. Our findings may explain, at least in part, the high rates of cardiovascular events observed in the course of atherothrombotic disease and support the need to improve antiplatelet therapy.

Effectiveness of Platelet Function Analysis-Guided Aspirin and/or Clopidogrel Therapy in Preventing Secondary Stroke: A Systematic Review and Meta-Analysis

“…These inconsistencies are probably caused by differences in the characteristics of the original studies. Firstly, the predictive value of HTPR for clinical outcomes may be complicated because of multiple etiologies [42], as the roles of the platelet reactivity may be different in different vascular diseases (cardiovascular versus cerebrovascular), [43] or even different subtypes of ischemic stroke. [44][45][46] The stroke subtype was identified only in the study by Yi et al, but not in the study by Depta et al The sample was more homogeneous in the study by Yi et al, as only two subtypes were included: atherothrombotic or small artery disease.…”

Platelet function testing in transient ischaemic attack and ischaemic stroke: A comprehensive systematic review of the literature

“…However, as this study was not designed to assess clinical outcomes in patients with HTPR, one cannot conclude that one should use higher dose IV rather than oral aspirin in acute stroke. The same authors reported the results of another cross-sectional whole blood impedance aggregometry study in 737 patients with CVD, IHD or peripheral vascular disease (PVD) on 100-200 mg of oral aspirin or 500 mg of IV aspirin daily [47]. Aspirin doses ranged between 100 and 500 mg daily in the CVD subgroup [47].…”

“…The same authors reported the results of another cross-sectional whole blood impedance aggregometry study in 737 patients with CVD, IHD or peripheral vascular disease (PVD) on 100-200 mg of oral aspirin or 500 mg of IV aspirin daily [47]. Aspirin doses ranged between 100 and 500 mg daily in the CVD subgroup [47]. The prevalence of aspirin-HTPR was 28% in patients with CVD, 18% in those with IHD and 22% in those with PAD.…”

Safety and Efficacy of Prasugrel in Elderly/Low Body Weight Japanese Patients with Ischemic Stroke: Randomized PRASTRO-II

“…Guidelines for management of stroke recommend antiplatelet therapy for secondary prevention of noncardioembolic ischemic stroke, and accordingly, several antiplatelet agents including clopidogrel and aspirin are currently in use [1][2][3]. However, there are poor responders to aspirin and clopidogrel [4][5][6], who have high risk of major adverse cardiovascular events [7][8][9][10]. Approximately 19% of Japanese patients are CYP2C19 poor metabolizers (PM) who can only attain a low concentration of the active metabolite of clopidogrel [11].…”