| 1. |
- Becker, Richard C., et al.
(författare)
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Chromogenic laboratory assays to measure the factor Xa-inhibiting properties of apixaban-an oral, direct and selective factor Xa inhibitor
- 2011
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Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 32:2, s. 183-187
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Tidskriftsartikel (refereegranskat)abstract
- An ability to readily determine an anticoagulant effect with an emerging class of direct, active site, oral factor Xa inhibitors is viewed by the medical community as attractive and by some as an absolute requirement for their use in clinical practice. We performed a pharmacokinetic and pharmacodynamic substudy in APPRAISE-1-a study of apixaban in patients with acute coronary syndrome(ACS). A total of 1691 patients had blood sampled for apixaban plasma concentrations using mass spectrometry/high performance liquid chromatography and anti-Xa activity using a chromogenic assay employing either low molecular weight heparin or apixaban as reference standards. Anti-Xa activity, determined by either anti-Xa-LMWH (r = 0.9671; P < 0.0001) or anti-Xa-apixaban (r = 0.9669; P < 0.0001) correlated strongly and in a linear fashion with apixaban plasma concentrations. The correlations for each method were equally strong at low (< 100 ng/ml) (r = 0.86, P < 0.0001; r = 0.85, P < 0.0001), intermediate(100-200 ng/ml) (r = 0.73, P < 0.0001; r = 0.69, P < 0.0001) and high (> 200 ng/ml) (r = 0.91, P < 0.0001; r = 0.91, P < 0.0001) plasma concentrations of apixaban, respectively. Our pharmacokinetic and pharmacodynamic substudy suggests that an apixaban-mediated anticoagulant effect can be detected even at very low plasma concentrations using a standard laboratory chromogenic anti-Xa assay with either LMWH or apixaban calibrators. While establishing parameters for safety and efficacy will require further investigation, an ability to discern the presence of a drug effect may provide clinically useful information.
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| 2. |
- Lopes, Renato D., et al.
(författare)
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Highlights from the III International Symposium of Thrombosis and Anticoagulation (ISTA), October 14-16, 2010, Sao Paulo, Brazil
- 2011
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Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 32:2, s. 242-266
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Tidskriftsartikel (refereegranskat)abstract
- To discuss and share knowledge around advances in the care of patients with thrombotic disorders, the Third International Symposium of Thrombosis and Anticoagulation was held in So Paulo, Brazil, from October 14-16, 2010. This scientific program was developed by clinicians for clinicians, and was promoted by four major clinical research institutes: the Brazilian Clinical Research Institute, the Duke Clinical Research Institute of the Duke University School of Medicine, the Canadian VIGOUR Centre, and the Uppsala Clinical Research Center. Comprising 3 days of academic presentations and open discussion, the symposium had as its primary goal to educate, motivate, and inspire internists, cardiologists, hematologists, and other physicians by convening national and international visionaries, thought-leaders, and dedicated clinician-scientists. This paper summarizes the symposium proceedings.
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| 3. |
- Lowenstern, Angela, et al.
(författare)
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Platelet-related biomarkers and their response to inhibition with aspirin and p2y12-receptor antagonists in patients with acute coronary syndrome
- 2017
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Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 44:2, s. 145-153
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Tidskriftsartikel (refereegranskat)abstract
- The PLATelet inhibition and patient Outcomes (PLATO) trial showed that treatment with ticagrelor reduced the rate of death due to vascular causes, myocardial infarction and stroke when compared to clopidogrel in patients with ST-elevation or non-ST-elevation acute coronary syndrome (ACS). While the comparative benefit of ticagrelor over clopidogrel increased over time, event rates accrued in both groups during the study period. The purpose of our biomarker-based exploratory analysis was to determine whether long-term platelet inhibition may be associated with platelet adaptation. A sample of 4000 participants from the PLATO trial also consented to participate in a prospectively designed biomarker substudy. Blood samples were procured at baseline, immediately prior to hospital discharge and at 1 and 6 months. Markers of platelet activity, including platelet count, serum CD40-ligand and soluble P-selectin were analyzed. Mean levels were compared at discharge, 1 and 6 months following study drug initiation-first for all patients and subsequently stratified by treatment group. A linear mixed model was used to estimate the short-term change rate (baseline to 1 month) and long-term change rate (1-6 months) for each biomarker. A Cox proportional hazards model was used to calculate hazard ratios for each change in biomarker over the two time periods examined: baseline to 1 month and 1 to 6 months. Prior to randomized treatment (baseline), sCD40 ligand and sP-selectin levels were elevated above the normal range of the assay (0.39 and 33.5 A μg/L, respectively). The mean level of each biomarker was significantly different at 1 month compared to baseline (p < 0.0001). When stratified by treatment group, at 1 month patients treated with ticagrelor had a larger increase in platelet count compared to those treated with clopidogrel (p < 0.0001). Similarly, when comparing biomarker levels for all patients at 6 months with those at 1 month, each differed significantly (p < 0.05). There was no significant difference between treatment groups during this time period. The rate of change for both platelet count and sP-selectin were significantly different between baseline and 1 month when compared to the 1 to 6-month time period (p < 0.0001). When comparing treatment groups, the rate of increase in platelets from baseline to 1 month was greater for patients treated with ticagrelor (p < 0.0001). This was no longer observed in the 1 to 6-month interval. Using a Cox proportional hazard model, the increase in platelet count from 1 to 6 months was associated with ischemic-thrombotic events, while sCD40 ligand decrease from 1 to 6 months was associated with hemorrhagic events. There were no differences between treatment groups for the associations with clinical endpoints. Dynamic changes in platelet count, sCD-40 ligand and sP-selectin occur over time among patients with ACS. Platelet-directed therapy with a P2Y12 receptor inhibitor in combination with aspirin modestly impacts the expression of these biomarkers. Platelet count and sCD40 ligand may offer modest overall predictive value for future ischemic-thrombotic or hemorrhagic clinical events, respectively. The existence of a platelet adaptome and its overall clinical significance among patients at risk for thrombotic events will require a more in-depth and platelet-biology specific investigation.
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| 4. |
- Åkerblom, Axel, 1977-, et al.
(författare)
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Prevalence and relevance of abnormal glucose metabolism in acute coronary syndromes : insights from the PLATelet inhibition and patient Outcomes (PLATO) trial
- 2019
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Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer. - 0929-5305 .- 1573-742X. ; 48:4, s. 563-569
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Tidskriftsartikel (refereegranskat)abstract
- Diabetes mellitus (DM) and abnormal glucose metabolism are associated with cardiovascular (CV) disease. We investigated the prevalence and prognostic importance of dysglycaemia in patients with acute coronary syndromes (ACS) in the PLATelet inhibition and patient Outcomes (PLATO) trial. Diabetes was defined as known diabetes or HbA1c >= 6.5% or non-fasting glucose >= 11.1 mmol/L on admission, prediabetes as HbA1c >= 5.7% but < 6.5%, and no diabetes as HbA1c < 5.7%. The primary endpoint was the composite of CV death, spontaneous myocardial infarction type 1 (sMI) or stroke at 12 months. Multivariable Cox regression models, adjusting for baseline characteristics, and biomarkers NT-proBNP and troponin I, were used to explore the association between glycaemia and outcome. On admission, 16,007 (86.1%) patients had HbA1c and/or glucose levels available and were subdivided into DM 38.5% (6160) (1501 patients had no previous DM diagnosis), prediabetes 38.8% (6210), and no DM 22.7% (3637). Kaplan Meier event rates at 12 months for CV death, sMI or stroke per subgroups were 14.5% (832), 9.0% (522), and 8.5% (293), respectively with multivariable adjusted HRs, versus no diabetes, for diabetes: 1.71 (1.50-1.95) and for prediabetes 1.03 (0.90-1.19). Corresponding event rates for CV death were 6.9% (391), 3.4% (195) and 3.0% (102), respectively, with adjusted HRs for patients with DM of: 1.92 (1.42-2.60) and for prediabetes 1.02 (0.79-1.32). Abnormal glucose metabolism is common in ACS patients, but only patients with definite DM have an increased CV risk, indicating that prediabetes is not immediately associated with worse CV outcomes.
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