Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

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Subject: search.filters.subject.Anticoagulants

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    An informatics consult approach for generating clinical evidence for treatment decisions
    (BioMed Central Ltd, 2021-12) Lai AG; Chang WH; Parisinos CA; Katsoulis M; Blackburn RM; Shah AD; Nguyen V; Denaxas S; Davey Smith G; Gaunt TR; Nirantharakumar K; Cox MP; Forde D; Asselbergs FW; Harris S; Richardson S; Sofat R; Dobson RJB; Hingorani A; Patel R; Sterne J; Banerjee A; Denniston AK; Ball S; Sebire NJ; Shah NH; Foster GR; Williams B; Hemingway H
    BACKGROUND: An Informatics Consult has been proposed in which clinicians request novel evidence from large scale health data resources, tailored to the treatment of a specific patient. However, the availability of such consultations is lacking. We seek to provide an Informatics Consult for a situation where a treatment indication and contraindication coexist in the same patient, i.e., anti-coagulation use for stroke prevention in a patient with both atrial fibrillation (AF) and liver cirrhosis. METHODS: We examined four sources of evidence for the effect of warfarin on stroke risk or all-cause mortality from: (1) randomised controlled trials (RCTs), (2) meta-analysis of prior observational studies, (3) trial emulation (using population electronic health records (N = 3,854,710) and (4) genetic evidence (Mendelian randomisation). We developed prototype forms to request an Informatics Consult and return of results in electronic health record systems. RESULTS: We found 0 RCT reports and 0 trials recruiting for patients with AF and cirrhosis. We found broad concordance across the three new sources of evidence we generated. Meta-analysis of prior observational studies showed that warfarin use was associated with lower stroke risk (hazard ratio [HR] = 0.71, CI 0.39-1.29). In a target trial emulation, warfarin was associated with lower all-cause mortality (HR = 0.61, CI 0.49-0.76) and ischaemic stroke (HR = 0.27, CI 0.08-0.91). Mendelian randomisation served as a drug target validation where we found that lower levels of vitamin K1 (warfarin is a vitamin K1 antagonist) are associated with lower stroke risk. A pilot survey with an independent sample of 34 clinicians revealed that 85% of clinicians found information on prognosis useful and that 79% thought that they should have access to the Informatics Consult as a service within their healthcare systems. We identified candidate steps for automation to scale evidence generation and to accelerate the return of results. CONCLUSION: We performed a proof-of-concept Informatics Consult for evidence generation, which may inform treatment decisions in situations where there is dearth of randomised trials. Patients are surprised to know that their clinicians are currently not able to learn in clinic from data on 'patients like me'. We identify the key challenges in offering such an Informatics Consult as a service.
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    Effects of a single subcutaneous dose of enoxaparin on veterinary viscoelastic coagulation monitor variables in healthy cats: Double blind, placebo controlled cross-over trial
    (Wiley Open Access, 10/12/2022) Yozova I; Kent M; Jandrey K
    BACKGROUND: Cats placed on anticoagulant medication require frequent monitoring. The veterinary viscoelastic coagulation monitor (VCM-Vet) could provide a convenient and cost-effective monitoring, enabling therapeutic decision making. HYPOTHESIS/OBJECTIVES: Enoxaparin will lead to changes in VCM-Vet variables and these will correlate with antiXa activity. ANIMALS: Twenty-one healthy cats. METHODS: Cats were randomized to receive either enoxaparin (1 mg/kg) subcutaneously or 0.9% NaCl (equal volume) and crossed over with a 7-day washout period. The investigators were blinded to group allocation until data analysis. Jugular blood samples were drawn at time 0, and 2, 4, and 8 hours after injection for VCM-Vet analysis within 2 min of collection. Citrated plasma was frozen at -80°C for antiXa activity analysis. A Generalized Linear Model was completed to assess changes between baseline measurements and all time points. RESULTS: Significant differences between the enoxaparin-treated cats and controls at for T0h and T2h were found and presented as mean ± SD for clotting time (enoxaparin, 593.4 ± 78.0 s; control, 448.5 ± 50.3 s, P < .001), clot formation time (enoxaparin, 183.1 ± 41.7 s; control, 155.4 ± 28.0 s, P = .001), and alpha angle (enoxaparin, 52.4 ± 6.1°; control, 56.9 ± 3.7 s, P = .003). AntiXa activity was significantly different between T0 and all other timepoints for the enoxaparin group (P < .001). There was no correlation between changes in clotting time and antiXa activity. CONCLUSIONS AND CLINICAL IMPORTANCE: The VCM-Vet detects a difference at 2 hours after single-dose enoxaparin administration and it can be useful for anticoagulant therapy monitoring in cats.