218 research outputs found

    Implications of the antiplatelet therapy gap left with discontinuation of prasugrel in Canada

    Get PDF
    Background The current Canadian Cardiovascular Society antiplatelet therapy guidelines recommend the use of ticagrelor or prasugrel over clopidogrel as first-line platelet P2Y12 receptor antagonists for treatment of moderate- to high-risk acute coronary syndromes. Recently, Effient (prasugrel [Eli Lilly Canada Inc, Toronto, Canada]) was discontinued by its distributor in Canada. Methods Five members of the Canadian Cardiovascular Society antiplatelet therapy 2018 guidelines committee undertook an independent, evidence-based review to outline patients for whom prasugrel should be the optimal P2Y12 agent and discuss alternative strategies to consider without prasugrel. Results Several clinical scenarios where prasugrel should be indicated are identified and discussed. Considerations to be undertaken for alternative therapies are summarized, including a review of national and international guidelines for de-escalation of P2Y12 receptor antagonists. Conclusions The discontinuation of prasugrel poses a challenge for clinicians. Clinicians must consider key factors in determining the best alternate therapy.Introduction Dans ses lignes directrices actuelles sur la thĂ©rapie antiplaquettaire, la SociĂ©tĂ© canadienne de cardiologie recommande l’utilisation du ticagrĂ©lor ou du prasugrel plutĂŽt que l’utilisation du clopidogrel comme antagonistes des rĂ©cepteurs plaquettaires P2Y12 de premiĂšre intention dans le traitement des patients qui prĂ©sentent un risque modĂ©rĂ© Ă  Ă©levĂ© de syndromes coronariens aigus. Depuis peu, le distributeur a cessĂ© la distribution d’Effient (prasugrel) au Canada. MĂ©thodes Cinq membres du comitĂ© des lignes directrices 2018 sur la thĂ©rapie antiplaquettaire de la SociĂ©tĂ© canadienne de cardiologie ont entrepris une revue indĂ©pendante fondĂ©e sur les donnĂ©es probantes pour dresser le profil des patients pour lesquels le prasugrel devrait ĂȘtre la meilleure option parmi les antagonistes des rĂ©cepteurs P2Y12 et se pencher sur les traitements alternatifs en l'absence de prasugrel. RĂ©sultats Plusieurs scĂ©narios cliniques oĂč le prasugrel devrait ĂȘtre indiquĂ© sont recensĂ©s et abordĂ©s. Les rĂ©flexions sur les solutions de rechange au traitement, notamment une revue des lignes directrices nationales et internationales en matiĂšre de dĂ©sescalade des antagonistes des rĂ©cepteurs P2Y12, sont prĂ©sentĂ©es. Conclusions La cessation de la distribution du prasugrel pose problĂšme aux cliniciens. Les cliniciens doivent tenir compte des facteurs clĂ©s pour dĂ©terminer le meilleur traitement de remplacement

    Head‐to‐Head comparison of consensus‐recommended platelet function tests to assess P2Y12 Inhibition : insights for multi‐center trials

    Get PDF
    The vasodilator‐associated stimulated phosphoprotein (VASP) phosphorylation level is a highly specific method to assess P2Y12 receptor inhibition. Traditionally, VASP phosphorylation is analyzed by flow cytometry, which is laborious and restricted to specialized laboratories. Recently, a simple ELISA kit has been commercialized. The primary objective of this study was to compare the performance of VASP assessment by ELISA and flow cytometry in relation to functional platelet aggregation testing by MultiplateÂź whole‐blood aggregometry. Blood from 24 healthy volunteers was incubated with increasing concentration of a P2Y12 receptor inhibitor (AR‐C 66096). Platelet function testing was carried out simultaneously by MultiplateÂź aggregometry and by VASP assessment through ELISA and flow cytometry. As expected, increasing concentrations of the P2Y12 receptor inhibitor induced a proportional inhibition of platelet aggregation and P2Y12 receptor activation across the modalities. Platelet reactivity index values of both ELISA‐ and flow cytometry‐ based VASP assessment methods correlated strongly (r = 0.87, p < 0.0001) and showed minimal bias (1.05%). Correlation with MultiplateÂź was slightly higher for the flow cytometry‐based VASP assay (r = 0.79, p < 0.0001) than for the ELISA‐based assay (r = 0.69, p < 0.0001). Intraclass correlation (ICC) was moderate for all the assays tested (ICC between 0.62 and 0.84). However, categorization into low, optimal, or high platelet reactivity based on these assays was strongly concordant (Îș between 0.86 and 0.92). In conclusion, the consensus‐recommended assays with their standardized cut‐offs should not be used interchangeably in multi‐center clinical studies but, rather, they should be standardized throughout sites

    Recognition of Transmembrane Protein 39A as a Tumor-Specific Marker in Brain Tumor

    Get PDF
    Transmembrane protein 39A (TMEM39A) belongs to the TMEM39 family. TMEM39A gene is a susceptibility locus for multiple sclerosis. In addition, TMEM39A seems to be implicated in systemic lupus erythematosus. However, any possible involvement of TMEM39A in cancer remains largely unknown. In the present report, we provide evidence that TMEM39A may play a role in brain tumors. Western blotting using an anti-TMEM39A antibody indicated that TMEM39A was overexpressed in glioblastoma cell lines, including U87-MG and U251-MG. Deep-sequencing transcriptomic profiling of U87-MG and U251-MG cells revealed that TMEM39A transcripts were upregulated in such cells compared with those of the cerebral cortex. Confocal microscopic analysis of U251-MG cells stained with anti-TMEM39A antibody showed that TMEM39A was located in dot-like structures lying close to the nucleus. TMEM39A probably located to mitochondria or to endosomes. Immunohistochemical analysis of glioma tissue specimens indicated that TMEM39A was markedly upregulated in such samples. Bioinformatic analysis of the Rembrandt knowledge base also supported upregulation of TMEM39A mRNA levels in glioma patients. Together, the results afford strong evidence that TMEM39A is upregulated in glioma cell lines and glioma tissue specimens. Therefore, TMEM39A may serve as a novel diagnostic marker of, and a therapeutic target for, gliomas and other cancers

    Platelet quiescence in patients with acute coronary syndrome undergoing coronary artery bypass graft surgery

    Get PDF
    BACKGROUND: The optimal antiplatelet strategy for patients with acute coronary syndromes who require coronary artery bypass surgery remains unclear. While a more potent antiplatelet regimen will predispose to perioperative bleeding, it is hypothesized that through “platelet quiescence,” ischemic protection conferred by such therapy may provide a net clinical benefit. METHODS AND RESULTS: We compared patients undergoing coronary artery bypass surgery who were treated with a more potent antiplatelet inhibition strategy with those with a less potent inhibition through a meta-analysis. The primary outcome was all-cause mortality after bypass surgery. The analysis identified 4 studies in which the antiplatelet regimen was randomized and 6 studies that were nonrandomized. Combining all studies, there was an overall higher mortality with weaker strategies compared with more potent strategies (odds ratio, 1.38; 95% CI, 1.03–1.85; P=0.03). CONCLUSIONS: Our findings support the concept of platelet quiescence, in reducing mortality for patients with acute coronary syndrome requiring coronary artery bypass surgery. This suggests the routine up-front use of potent antiplatelet regimens in acute coronary syndrome, irrespective of likelihood of coronary artery bypass graft

    Lack of benefits for prevention of cardiovascular disease with aspirin therapy in type 2 diabetic patients - a longitudinal observational study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The risk-benefit ratio of aspirin therapy in prevention of cardiovascular disease (CVD) remains contentious, especially in type 2 diabetes. This study examined the benefit and harm of low-dose aspirin (daily dose < 300 mg) in patients with type 2 diabetes.</p> <p>Methods</p> <p>This is a longitudinal observational study with primary and secondary prevention cohorts based on history of CVD at enrolment. We compared the occurrence of primary composite (non-fatal myocardial infarction or stroke and vascular death) and secondary endpoints (upper GI bleeding and haemorrhagic stroke) between aspirin users and non-users between January 1995 and July 2005.</p> <p>Results</p> <p>Of the 6,454 patients (mean follow-up: median [IQR]: 4.7 [4.4] years), usage of aspirin was 18% (n = 1,034) in the primary prevention cohort (n = 5731) and 81% (n = 585) in the secondary prevention cohort (n = 723). After adjustment for covariates, in the primary prevention cohort, aspirin use was associated with a hazard-ratio of 2.07 (95% CI: 1.66, 2.59, p < 0.001) for primary endpoint. There was no difference in CVD event rate in the secondary prevention cohort. Overall, aspirin use was associated with a hazard-ratio of 2.2 (1.53, 3.15, p < 0.001) of GI bleeding and 1.71 (1.00, 2.95, p = 0.051) of haemorrhagic stroke. The absolute risk of aspirin-related GI bleeding was 10.7 events per 1,000 person-years of treatment.</p> <p>Conclusion</p> <p>In Chinese type 2 diabetic patients, low dose aspirin was associated with a paradoxical increase in CVD risk in primary prevention and did not confer benefits in secondary prevention. In addition, the risk of GI bleeding in aspirin users was rather high.</p

    International Expert Consensus on Switching Platelet P2Y(12) Receptor-Inhibiting Therapies

    Get PDF
    Dual antiplatelet therapy with aspirin and a P2Y(12) inhibitor is the treatment of choice for the prevention of atherothrombotic events in patients with acute coronary syndromes and for those undergoing percutaneous coronary interventions. The availability of different oral P2Y(12) inhibitors (clopidogrel, prasugrel, ticagrelor) has enabled physicians to contemplate switching among therapies because of specific clinical scenarios. The recent introduction of an intravenous P2Y(12) inhibitor (cangrelor) further adds to the multitude of modalities and settings in which switching therapies may occur. In clinical practice, it is not uncommon to switch P2Y(12) inhibitor, and switching may be attributed to a variety of factors. However, concerns about the safety of switching between these agents have emerged. Practice guidelines have not fully elaborated on how to switch therapies, leaving clinicians with limited guidance on when and how to switch therapies when needed. This prompted the development of this expert consensus document by key leaders from North America and Europe with expertise in basic, translational, and clinical sciences in the field of antiplatelet therapy. This expert consensus provides an overview of the pharmacology of P2Y(12) inhibitors, different modalities and definitions of switching, and available literature and recommendations for switching between P2Y(12) inhibitors
    • 

    corecore