| 1. |
- Becker, Richard C., et al.
(författare)
-
Chromogenic laboratory assays to measure the factor Xa-inhibiting properties of apixaban-an oral, direct and selective factor Xa inhibitor
- 2011
-
Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 32:2, s. 183-187
-
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.
|
|
| 2. |
- Damman, Peter, et al.
(författare)
-
P2Y12 platelet inhibition in clinical practice
- 2012
-
Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 33:2, s. 143-153
-
Tidskriftsartikel (refereegranskat)abstract
- Platelet adhesion, activation and aggregation play a pivotal role in atherothrombosis. Intracoronary atherothrombosis is the most common cause of the development of acute coronary syndrome (ACS), and plays a central role in complications occurring around percutaneous coronary intervention (PCI) including recurrent ACS, procedure-related myocardial infarction or stent thrombosis. Inhibition of platelet aggregation by medical treatment impairs formation and progression of thrombotic processes and is therefore of great importance in the prevention of complications after an ACS or around PCI. An essential part in the platelet activation process is the interaction of adenosine diphosphate (ADP) with the platelet P2Y12 receptor. The P2Y12 receptor is the predominant receptor involved in the ADP-stimulated activation of the glycoprotein IIb/IIIa receptor. Activation of the glycoprotein IIb/IIIa receptor results in enhanced platelet degranulation and thromboxane production, and prolonged platelet aggregation. The objectives of this review are to discuss the pharmacological limitations of the P2Y12 inhibitor clopidogrel, and describe the novel alternative P2Y12 inhibitors prasugrel and ticagrelor and the clinical implications of the introduction of these new medicines.
|
|
| 3. |
- Gharacholou, S. Michael, et al.
(författare)
-
Antithrombotic therapy in acute coronary syndromes : guidelines translated for the clinician
- 2010
-
Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 29:4, s. 516-528
-
Tidskriftsartikel (refereegranskat)abstract
- The use of anticoagulant and antiplatelet therapy during the management of acute coronary syndromes (ACS) has been associated with improvements in short- and long-term clinical outcomes, regardless of whether patients are managed conservatively or with acute coronary revascularization. Translating the existing evidence for selection of the most appropriate antithrombotic strategy has been summarized in available guideline recommendations. Given the breadth of antithrombotic recommendations across existing U.S. and European guidelines, synthesis of these recommendations for practicing clinicians who treat patients with ACS are increasingly desired. Providing a summary of the similarities across guidelines while noting the areas where divergence exists becomes an important facet in translating optimal antithrombotic management in ACS for the treating clinician. This review highlights the important aspects of clinical practice guidelines that practicing physicians should consider when selecting antithrombotic therapies to reduce ischemic risk while minimizing hemorrhagic risk across all ACS subtypes.
|
|
| 4. |
- Guimaraes, Patricia O., et al.
(författare)
-
International normalized ratio control and subsequent clinical outcomes in patients with atrial fibrillation using warfarin
- 2019
-
Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 48:1, s. 27-34
-
Tidskriftsartikel (refereegranskat)abstract
- We explored associations between INR measures and clinical outcomes in patients with AF using warfarin, and whether INR history predicted future INR measurements. We included patients in ARISTOTLE who were randomized to and received warfarin. Among patients who had events, we included those with ≥ 3 INR values in the 180 days prior to the event, with the most recent ≤ 60 days prior to the event, who were on warfarin at the time of event (n = 545). Non-event patients were included in the control group if they had ≥ 180 days of warfarin exposure with ≥ 3 INR measurements (n = 7259). The median (25th, 75th) number of INR values per patient was 29 (21, 38) over a median follow-up of 1.8 years. A total of 87% had at least one INR value < 1.5; 49% had at least one value > 4.0. The last INRs before events (median 14 [24, 7] days) were < 3.0 for at least 75% of patients with major bleeding and > 2.0 for half of patients with ischemic stroke. Historic time in therapeutic range (TTR) was weakly associated with future TTR (R2 = 0.212). Historic TTR ≥ 80% had limited predictive ability to discriminate future TTR ≥ 80% (C index 0.61). In patients with AF receiving warfarin, most bleeding events may not have been preventable despite careful INR control. Our findings suggest that INRs collected through routine management are not sufficiently predictive to provide reassurance about future time in therapeutic range or to prevent subsequent outcomes, and might be over-interpreted in clinical practice.
|
|
| 5. |
- Hamilos, Michalis, et al.
(författare)
-
Relationship between peripheral arterial reactive hyperemia and residual platelet reactivity after 600 mg clopidogrel
- 2011
-
Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 32:1, s. 64-71
-
Tidskriftsartikel (refereegranskat)abstract
- Clopidogrel reduces long-term ischemic events in patients with acute coronary syndrome or stable angina (SA) undergoing percutaneous coronary intervention (PCI). Endothelial function improvement has been proposed, among other factors, for this beneficial effect of clopidogrel, but whether this might be associated to its anti-platelet action remains unclear. We tested the hypothesis that clopidogrel improvement of peripheral vascular endothelial function might be associated with inhibition of platelet aggregation. Endothelial function was evaluated before and at least 12 h after 600 mg clopidogrel in 43 SA pts undergoing elective PCI by: (a) reactive hyperemia peripheral arterial tonometry (measuring the Endoscore); (b) circulating endothelial microparticles (EMPs). Response to clopidogrel was measured with point-of-care VerifyNow P2Y12 assay and expressed as platelet reaction unit (PRU) and percent platelet inhibition (%PI). High platelet reactivity after clopidogrel was defined as PRU ≥ 240. Endothelial function improved after clopidogrel in 20 pts. Changes in Endoscore (Δ Endoscore) were significantly correlated with both PRU (r = -0.61, P < 0.001) and %PI (r = 0.57, P < 0.001). Endoscore significantly increased after clopidogrel in pts with PRU < 240 (0.38 ± 0.26 to 0.57 ± 0.33, P < 0.001), but did not in pts with PRU ≥ 240 (0.53 ± 0.31 to 0.40 ± 0.37, P = 0.12). EMPs were also significantly reduced in pts with PRU < 240 (222 [140-593] to 142 [83-371]/μl, P = 0.001), while no changes were observed in pts with PRU ≥ 240 (256 [178-531] to 388 [238-499]/μl, P = 0.55). In patients with stable coronary artery disease, a single 600 mg clopidogrel loading dose improves vascular endothelial function. This improvement is associated with optimal platelet inhibition and it is not observed in patients with post-clopidogrel high platelet reactivity.
|
|
| 6. |
- Helmersson-Karlqvist, Johanna, et al.
(författare)
-
Evaluation of the Alere D-dimer test for point of care testing
- 2014
-
Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 38:2, s. 250-252
-
Tidskriftsartikel (refereegranskat)abstract
- The primary care regularly sees patients that have symptoms that could be due to thromboembolic diseases. It would be valuable to be able to rule out deep venous thrombosis or pulmonary embolism using Wells score and a negative D-dimer testing already at the primary care unit. This requires a validated D-dimer assay suitable for primary care use. We compared D-dimer results obtained with the new point of care analyzer Alere Triage(®) and the central hospital laboratory STA-R Evolution analyzer from the same patient samples (n = 102). We also calculated the total coefficient of variation (CV) for the Alere method. The two methods showed a good linear correlation (R(2) = 0.977) and a slope of 0.975. CV for the Alere D-dimer method was well below 10 %. The study shows that the Alere D-dimer assay and the central laboratory standard assay show similar results. We suggest that the Alere D-dimer assay could be used in primary care in combination with Wells score to reduce referrals to the emergency unit.
|
|
| 7. |
- Jansson, Martin, et al.
(författare)
-
Reduced dose direct oral anticoagulants compared with warfarin with high time in therapeutic range in nonvalvular atrial fibrillation
- 2023
-
Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Nature. - 0929-5305 .- 1573-742X. ; 55:3, s. 415-425
-
Tidskriftsartikel (refereegranskat)abstract
- Direct oral anticoagulants (DOACs) used in nonvalvular atrial fibrillation (NVAF) are dose-reduced in elderly and patients with impaired renal function. Only reduced dose dabigatran is concluded as having similar stroke risk reduction and lower risk of major bleeding than warfarin in the pivotal studies. In clinical practice, reduced dose is prescribed more often than expected making this an important issue. The objective of this study was to compare effectiveness and safety between reduced dose DOACs and high TTR warfarin treatment (TTR ≥ 70%) in NVAF. A Swedish anticoagulation registry was used in identifying eligible patients from July 2011 to December 2017. The study cohort consisted of 40,564 patients with newly initiated DOAC (apixaban, dabigatran, or rivaroxaban) (11,083 patients) or warfarin treatment (29,481 patients) after exclusion of 374,135 patients due to not being warfarin or DOAC naïve, not being prescribed reduced dose, having previous mechanical heart valve (MHV), or being under 18 years old. The median durations of follow up were 365, 419, 432 and 473 days for apixaban, dabigatran, rivaroxaban and warfarin, respectively. Warfarin TTR identified from Auricula was 70.0%. Endpoints (stroke and major bleeding) and baseline characteristics were collected from hospital administrative registers using ICD-10 codes. Cohorts were compared using weighted adjusted Cox regression after full optimal matching based on propensity scores. DOACs are associated with lower risk of major bleeding (HR with 95% CI) 0.85 (0.78–0.93), intracranial bleeding HR 0.64 (0.51–0.80), hemorrhagic stroke HR 0.68 (0.50–0.92), gastrointestinal bleeding HR 0.81 (0.69–0.96) and all-cause stroke HR 0.87 (0.76–0.99), than warfarin. Apixaban and dabigatran are associated with lower risk of major bleeding, HR 0.70 (0.63–0.78) and HR 0.80 (0.69–0.94), and rivaroxaban is associated with lower risk of ischemic stroke, HR 0.73 (0.59–0.96), with higher major bleeding risk, HR 1.31 (1.15–1.48), compared to warfarin. Apixaban is associated with higher all-cause mortality compared to warfarin, HR 1.12 (1.03–1.21). DOACs are associated with lower risk of major bleeding and all-cause stroke, than high quality warfarin treatment, with exception of rivaroxaban that carried higher risk of major bleeding and lower risk of stroke or systemic embolism. In this large observational registry-based NVAF cohort, DOACs are preferred treatment in patients with indication for DOAC dose reduction, even in a high TTR setting.
|
|
| 8. |
- Lindh, Jonatan D, et al.
(författare)
-
Incidence and predictors of severe bleeding during warfarin treatment
- 2008
-
Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 25:2, s. 151-159
-
Tidskriftsartikel (refereegranskat)abstract
- Background Optimal warfarin prescription requires correct, individualized assessment of the warfarin-related bleeding risk, which randomised controlled trials may underestimate . Observational studies have reported a range of bleeding risks that differ 40-fold. This variation may be caused by time trends, variation in bleeding definition and study subject selection. We investigated the incidence of, and risk factors for severe bleeding in un-selected warfarin-treated patients from Sweden. Methods Between 2001 and 2005, 40 centres recruited warfarin-naive patients commencing warfarin therapy and followed them prospectively with continuous registration of clinical data. The primary outcome was severe bleeding, according to the WHO universal definition of severe adverse drug reactions. The influence of potential risk factors was investigated by means of a Cox proportional-hazards model. Result A total of 1523 patients contributed 1276 warfarin-exposed patient-years. The incidence of first-time severe bleeding was 2.3 per 100 patient-years (95% confidence interval 1.4 to 3.1). Male sex and use of drugs potentially interacting with warfarin were the only independent risk factors of severe bleeding, with hazard ratios of 2.8 and 2.3, respectively. Age, target International Normalized Ratio (INR), time spent outside target INR range, and warfarin dose requirement were not significantly associated with bleeding risk. Conclusions The risk of severe bleeding in a large naturalistic, prospective cohort of first-time warfarin users was lower than reported in some previous reports. Male gender was an independent predictor of severe bleeding as was the receipt of warfarin-interacting medications at the onset of anticoagulation therapy. Further studies are required to evaluate the effect these findings may have on the quality of current risk-benefit analysis involved in warfarin prescription.
|
|
| 9. |
- Lopes, Renato D., et al.
(författare)
-
Highlights from the III International Symposium of Thrombosis and Anticoagulation (ISTA), October 14-16, 2010, Sao Paulo, Brazil
- 2011
-
Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 32:2, s. 242-266
-
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.
|
|
| 10. |
- Lowenstern, Angela, et al.
(författare)
-
Platelet-related biomarkers and their response to inhibition with aspirin and p2y12-receptor antagonists in patients with acute coronary syndrome
- 2017
-
Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 44:2, s. 145-153
-
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.
|
|
