Thromb Haemostasis
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In contrast to short thrombelastography (s-TEG) which utilises adenosine diphosphate (ADP) alone, the VerifyNow P2Y12 assay (VN-P2Y12) additionally uses prostaglandin E1 (PGE1) as agonist to assess response to P2Y12 inhibitors. Based upon previous observations, we hypothesised that VN-P2Y12 overestimates the therapeutic effects of clopidogrel. Simultaneous assay with s-TEG and VN-P2Y12 was performed in 43 healthy volunteers and 170 patients either on or off clopidogrel. ⋯ Furthermore, adding PGE1 to ADP in s-TEG potentiated the anti-aggregatory effects of clopidogrel compared with ADP alone. In conclusion, VN-P2Y12 overestimates the functional effects of clopidogrel in some individuals, possibly because it utilises PGE1 in addition to ADP. This could have implications for the ability of VN-P2Y12 to stratify patients as "responders" or "non-responders" to clopidogrel.
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Atrial fibrillation (AF) causes a third of all strokes, but often goes undetected before stroke. Identification of unknown AF in the community and subsequent anti-thrombotic treatment could reduce stroke burden. We investigated community screening for unknown AF using an iPhone electrocardiogram (iECG) in pharmacies, and determined the cost-effectiveness of this strategy. ⋯ Screening with iECG in pharmacies with an automated algorithm is both feasible and cost-effective. The high and largely preventable stroke/thromboembolism risk of those with newly identified AF highlights the likely benefits of community AF screening. Guideline recommendation of community iECG AF screening should be considered.
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Comparative Study
Consistency of thromboelastometry analysis under scrutiny: results of a systematic evaluation within and between analysers.
While the use of thromboelastometry analysis (ROTEM®) in evaluation of haemostasis is rapidly increasing, important validity parameters of testing remain inadequately examined. We aimed to study systematically the consistency of thromboelastometry parameters within individual tests regarding measurements between different analysers, between different channels of the same analyser, between morning and afternoon measurements (circadian variation), and if measured four weeks apart. Citrated whole blood samples from 40 healthy volunteers were analysed with two analysers in parallel. ⋯ On average, comparisons of MCF, ML and LI30 measurements tended to be better, but none of the tests assessed outperformed another. In conclusion, systematic investigation reveals large differences in the results of some thromboelastometry parameters and lack of consistency. Clinicians and scientists should take these inconsistencies into account and focus on parameters with a higher homogeneity such as MCF.
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Large Phase 3 clinical trials for stroke prevention in atrial fibrillation (AF) have compared non-vitamin K antagonist oral anticoagulants (NOACs) against warfarin, with the edoxaban trial only recently reported. In the absence of head to head trials directly comparing these NOACs against each other, we compared the efficacy and safety of edoxaban to other agents by an indirect comparison analysis. We performed an indirect comparison analysis of edoxaban (2 dose strategies) against apixaban (1 dose), dabigatran etexilate (2 doses) and rivaroxaban (1 dose), for their relative efficacy and safety against each other. ⋯ Dabigatran 150 mg bid and rivaroxaban were associated with lower stroke/SE and ischaemic stroke, but higher bleeding rates. In the present analysis, we have provided for the first time, comparisons of efficacy and safety of edoxaban against other NOACs. Notwithstanding the significant limitations of an indirect comparison analysis, some differential effects are evident with the NOACs for stroke prevention, allowing us to allow the prescriber a 'choice' to be able to fit the drug to the patient clinical profile (and vice versa).