Lordkipanidze, M. et al. A comparison of six major platelet function tests to determine the prevalence of aspirin resistance in patients with stable coronary artery disease. Eur. Heart J. 28, 1702-1708

Faculty of Pharmacy, Université de Montréal, Montréal, Québec, Canada.
European Heart Journal (Impact Factor: 15.2). 08/2007; 28(14):1702-8. DOI: 10.1093/eurheartj/ehm226
Source: PubMed


We sought to compare the results obtained from six major platelet function tests in the assessment of the prevalence of aspirin resistance in patients with stable coronary artery disease.
201 patients with stable coronary artery disease receiving daily aspirin therapy (> or =80 mg) were recruited. Platelet aggregation was measured by: (i) light transmission aggregometry (LTA) after stimulation with 1.6 mM of arachidonic acid (AA), (ii) LTA after adenosine diphosphate (ADP) (5, 10, and 20 microM) stimulation, (iii) whole blood aggregometry, (iv) PFA-100, (v) VerifyNow Aspirin; urinary 11-dehydro-thromboxane B(2) concentrations were also measured. Eight patients (4%, 95% CI 0.01-0.07) were deemed resistant to aspirin by LTA and AA. The prevalence of aspirin resistance varied according to the assay used: 10.3-51.7% for LTA using ADP as the agonist, 18.0% for whole blood aggregometry, 59.5% for PFA-100, 6.7% for VerifyNow Aspirin, and finally, 22.9% by measuring urinary 11-dehydro-thromboxane B(2) concentrations. Results from these tests showed poor correlation and agreement between themselves.
Platelet function tests are not equally effective in measuring aspirin's antiplatelet effect and correlate poorly amongst themselves. The clinical usefulness of the different assays to classify correctly patients as aspirin resistant remains undetermined.

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Available from: Marie Lordkipanidzé, Jun 02, 2014
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    • "The global burden of cardiovascular disease in developing countries is over 60% and in.1 Since the accumulation of platelets is highly effective on causing cardiovascular diseases, the inhibition of this phenomenon can play an important role in preventing cardiovascular diseases.2 Despite recent developments in new platelet medications in the past decades, aspirin is still one of the most commonly used medication for preventing cardiovascular diseases worldwide.3-7 The clinical effectiveness of aspirin in preventing cardiovascular events has been well proven. "
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    ABSTRACT: Background The rate of cardiovascular diseases in developing countries is approximately 60% and it is still has an increasing trend. The clinical effectiveness of aspirin in preventing cardiovascular events has been well proven. Although aspirin is an effective and inexpensive drug, its consumption is not equally beneficial for all patients. Many factors can be affective on the efficacy of antiplatelet drugs such as aspirin. Methods This study was carried out on 260 patients who had stable angina pectoris and coronary artery disease was approved by coronary angiography. Based on opium addiction, the patients were divided into two groups. Opium addiction was diagnosed base on Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) criteria. The mid-stream morning urinary sample were collected for measuring the urinary 11-dehydroxy thromboxane B2 level (UTXB2). Urinary level of UTXB2 was considered as an aspirin resistance index. Findings The mean age of patients was 57.3 ± 8.9; and 44.6% of them were females. The aspirin resistance rate was 41.5%. Significant difference in aspirin resistance was observed between the opium addicts and non-addicts. (51.5% vs. 31.5%) (P = 0.001). The effects of confounding variables such as diabetes, hypertension, and hyperlipidemia were eliminated by regression logistic multivariable analysis. Conclusion The prevalence of aspirin resistance in patients with stable angina pectoris was 41.5%. The prevalence of aspirin resistance in patients with stable angina pectoris who had opium addiction was significantly higher them non-addicts.
    03/2014; 6(1-2):7-13.
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    • "Considering the strong evidence in favor of aspirin use, this prevalence is particularly noteworthy. Although several studies demonstrate a low prevalence of aspirin-resistance (0–2.8%),[18],[19] most studies report a relatively high rate (5.5%–33%) of aspirin resistance in patients with cardiovascular disease.[16],[17],[20]–[22] "
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    ABSTRACT: To assess the prevalence of and related risk factors for aspirin resistance in elderly patients with coronary artery disease (CAD). Two hundred and forty-six elderly patients (75.9 ± 7.4 years) with CAD who received daily aspirin therapy (≥ 75 mg) over one month were recruited. The effect of aspirin was assessed using light transmission aggregometry (LTA) and thrombelastography platelet mapping assay (TEG). Aspirin resistance was defined as ≥ 20% arachidonic acid (AA)-induced aggregation and ≥ 70% adenosine diphosphate (ADP)-induced aggregation in the LTA assay. An aspirin semi-responder was defined as meeting one (but not both) of the criteria described above. Based on the results of TEG, aspirin resistance was defined as ≥ 50% aggregation induced by AA. As determined by LTA, 23 (9.3%) of the elderly CAD patients were resistant to aspirin therapy; 91 (37.0%) were semi-responders. As determined by TEG, 61 patients (24.8%) were aspirin resistant. Of the 61 patients who were aspirin resistant by TEG, 19 were aspirin resistant according to LTA results. Twenty-four of 91 semi-responders by LTA were aspirin resistant by TEG. Multivariate logistic regression analysis revealed that elevated fasting serum glucose level (Odds ratio: 1.517; 95% CI: 1.176-1.957; P = 0.001) was a significant risk factor for aspirin resistance as determined by TEG. A significant number of elderly patients with CAD are resistant to aspirin therapy. Fasting blood glucose level is closely associated with aspirin resistance in elderly CAD patients.
    Journal of Geriatric Cardiology 03/2013; 10(1):21-7. DOI:10.3969/j.issn.1671-5411.2013.01.005 · 1.40 Impact Factor
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    • "There is no official guideline recommending one assay above another, and platelet function testing is not recommended for routine clinical testing in patients requiring aspirin therapy [13]. As a result, many of the available platelet function assays have been used in a research capacity, and part of the uncertainty surrounding the definition and clinical relevance of aspirin resistance is due to the non-interchangeable nature of these assays [14]. As a consequence, there is a need to address basic questions on the prognostic and diagnostic utility and cost-effectiveness of platelet function testing in the context of aspirin therapy before testing can be recommended in clinical practice. "
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    ABSTRACT: Background The benefits of aspirin as an anti-platelet agent are well established; however, there has been much debate about the lack of uniformity in the efficacy of aspirin to inhibit platelet function. In some patients, aspirin fails to inhibit platelets even where compliance has been verified, a phenomenon which has been termed “aspirin resistance”. These patients may in turn be at a higher risk of future vascular events. The proportion of “resistant” patients identified depends on the type of platelet function test. Therefore, the aim of this systematic review is to determine which, if any, platelet function test has utility in terms of identifying patients with a high risk of vascular events. The review has been registered with PROSPERO (CRD42012002151). Methods Relevant studies will be sought from bibliographic databases. Trials registers will be searched for ongoing studies. Reference lists will be checked and subject experts contacted. There will be no date or language restrictions. Standard reviewing methodology to minimise bias will be employed. Any prospective studies in patients on aspirin therapy and assessing platelet function in relation to relevant clinical outcomes will be included, as will studies reporting prognostic models. Risk of bias assessment will be based on the Quality Assessment of Diagnostic Accuracy Studies guidelines, and suitable criteria for assessing quality of prognostic studies. Data on test accuracy measures, relative risks, odds or hazard ratios will be extracted and meta-analysed, where possible, using a random-effects model to account for between-study heterogeneity. Where appropriate, the causes of heterogeneity will be explored through meta-regression and sub-group or sensitivity analyses. If platelet function testing is demonstrated to have diagnostic/predictive utility in a specific population, the potential for a cost-effectiveness analysis will be considered and, if possible, an economic model constructed. This will be supported by a systematic review of existing economic evaluation studies. Discussion The results of the review could indicate if platelet function test(s) could lead to a reliable prediction of the risk of clinically important events in a defined population, and thus support investigations into adjustments to therapy in order to compensate for a predicted poor response to standard aspirin.
    Systematic Reviews 02/2013; 2(1):16. DOI:10.1186/2046-4053-2-16
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