RESUMO
VerifyNow (VN) test is a less laborious method to assess pharmacodynamics (PD) compared to light transmittance aggregometry (LTA). VN assay has not been used to study the immediate PD effects of acetylsalicylic acid (ASA). Ten healthy volunteers were randomly assigned to a single 162 or 650 mg dose of chewed and swallowed ASA. Pharmacodynamic and pharmacokinetic measurements were performed at baseline and serially up to 60 min after ASA administration. Onset by VN was 20 ± 7 min with 162 mg and 13 ± 7 min with 650 mg ASA (p = .07). Onset by 1 mM AA-induced PA was 13 ± 12 min with 162 mg and 7 ± 3 min with 650 mg ASA (p=NS). VN correlated with AA-induced PA (r = 0.80, p < .001) and serum TxB2 levels (r = 0.76, p < .001). 95% inhibition of serum TxB2 was achieved at 38 ± 22 min and 22 ± 8 min with the 162 and 650 mg ASA, respectively (p = .08). The onset and extent of the antiplatelet effect of 650 mg ASA is numerically faster and greater than the 162 mg dose. VN identifies the onset, extent, and dose response to ASA therapy. The ease of using VN should facilitate multicenter PD investigations of ASA.
Aspirin (acetylsalicylic acid) is an important drug widely used to prevent adverse ischemic events in patients with cardiovascular disease. Platelet aggregation and thromboxane B2 levels in blood samples by complex laboratory methods are used to assess platelet response to aspirin. VerifyNow assay is a simple laboratory test that has not been used to assess the immediate effect of aspirin. In this study, conducted in 10 healthy volunteers, we compared the immediate platelet response to aspirin by serially assessing platelet aggregation by aggregometry and VerifyNow assay, and thromboxane B2 levels. We also measured plasma levels of acetylsalicylic acid and salicylic acid. Our study demonstrated that the VerifyNow Aspirin test identifies the onset, extent, and dose-response to aspirin therapy. The ease of using the VerifyNow test should facilitate multicenter pharmacodynamic investigations of aspirin.
Assuntos
Aspirina , Inibidores da Agregação Plaquetária , Humanos , Aspirina/farmacologia , Aspirina/uso terapêutico , Inibidores da Agregação Plaquetária/uso terapêutico , Inibidores da Agregação Plaquetária/farmacocinética , Agregação PlaquetáriaRESUMO
Aspirin (ASA) remains the most common antiplatelet agent used in children. VerifyNow Aspirin Test® (VN) assesses platelet response to ASA, with therapeutic effect defined by the manufacturer as ≤ 549 aspirin reaction units (ARU). Single-center, observational, analysis of 195 children (< 18 years-old) who underwent first VN between 2015 and 2020. Primary outcome was proportion of patients with ASA biochemical resistance (> 549 ARU). Secondary outcomes included incidence of new clinical thrombotic and bleeding events during ≤ 6 months from VN in those who received ASA monotherapy (n = 113). Median age was 1.8 years. Common indications for ASA included cardiac anomalies or dysfunction (74.8%) and ischemic stroke (22.6%). Median ASA dose before VN was 4.6 mg/kg/day. Mean VN was 471 ARU. ASA biochemical resistance was detected in 14.4% (n = 28). Of 113 patients receiving ASA monotherapy, 14 (12.4%) had a thrombotic event and 2 (1.8%) had a bleeding event. Mean VN was significantly higher at initial testing in patients experiencing thrombotic event compared to those without thrombosis (516 vs 465 ARU, [95% CI: 9.8, 92.2], p = 0.02). Multivariable analysis identified initial VN ASA result ≥ 500 ARU at initial testing as the only significant independent risk factor for thrombosis (p < 0.01). VN testing identifies ASA biochemical resistance in 14.4% of children. VN ASA ≥ 500 ARU rather than ≥ 550 ARU at initial testing was independently associated with increased odds of thrombosis. Designated cut-off of 550 ARU for detecting platelet dysfunction by ASA may need reconsideration in children.
Assuntos
Aspirina , Trombose , Adolescente , Criança , Humanos , Lactente , Aspirina/efeitos adversos , Incidência , Inibidores da Agregação Plaquetária/efeitos adversos , Fatores de Risco , Trombose/prevenção & controle , Trombose/tratamento farmacológicoRESUMO
OBJECTIVES: To assess the prevalence and the association between aspirin resistance in critical limb ischemia patients using the VerifyNow® bed-side platelet test, and occurrence of cardiovascular morbidity and/or death at one year. MATERIALS AND METHODS: National multicenter prospective observational study related to COPART II centers. From 2010 through 2014, 64 subjects hospitalized for critical limb ischemia and already treated by aspirin before the VerifyNow® test were included. A VerifyNow® test>550 ARU was defined as aspirin resistance. Critical limb ischemia was defined according to the TASC I criteria. The primary outcome was a composite including death, acute coronary syndrome, stroke and major amputation during the one-year follow-up period. RESULTS: In all, 9/64 patients were aspirin resistant, the status was confirmed in one case. The prevalence of aspirin resistance was 14.06%. There was no significant difference between aspirin resistant and aspirin non-resistant groups in terms of cardiovascular history and glycemia status. Neither was there significant difference between the two groups in terms of survival. CONCLUSION: Aspirin resistance was not predictive of poorer survival in critical limb ischemia patients. However, our population was limited. Considering that a clear definition of aspirin resistance and standardized diagnostic tests are lacking, complementary studies might be useful.