Thromb Haemostasis
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Residual venous obstruction (RVO) could improve the stratification of the risk of recurrence after unprovoked deep vein thrombosis (DVT), but results from clinical studies and study-level meta-analyses are conflicting. It was the objective of this analysis to determine if RVO is a valid predictor of recurrent venous thromboembolism (VTE) in patients with a first unprovoked DVT who had received at least three months of anticoagulant therapy. Individual patient data were obtained from the datasets of original studies, after a systematic search of electronic databases (Medline, Embase, Cochrane Library), supplemented by manual reviewing of the reference lists and contacting content experts. ⋯ The association was stronger if RVO was detected early, i.e. at three months after DVT (HR = 2.17; 95% CI: 1.11-4.25), but non-significant if detected later, i.e. >6 months (HR = 1.19; 95% CI: 0.87-1.61). In conclusion, after a first unprovoked DVT, RVO is a weak overall predictor of recurrent VTE. The association is stronger if RVO is detected at an earlier time (3 months) after thrombosis.
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The recently published, largest trial with cangrelor, the Cangrelor versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition (CHAMPION)-PHOENIX, suggested that the experimental agent significantly reduced the rate of stent thrombosis (ST) and myocardial infarction (MI) during PCI at 48 hours (h) and 30 days. However, the declared impressive cangrelor vascular non-fatal benefit was contradicted by identical deaths at 48 h, and a trend toward excess mortality at 30 days. We analysed the mismatch between outcomes in the CHAMPION-PHOENIX trial. ⋯ The dissociation between vascular mortality and non-fatal vascular ischaemic occlusions, unless compensated by some other unreported cause(s) of death, should be explored and explained. Unadjudicated 30-day outcomes, and all ST types should be fully disclosed. The ongoing FDA cangrelor review should focus on appropriate event count and/or possible mismatch between site-reported and extra adjudicated events in the CHAMPION-PHOENIX trial.
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Multicenter Study
Persistent enhanced platelet activation in patients with acute myocardial infarction and coronary microvascular obstruction: clinical implications.
About 30% of patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing recanalisation of the infarct-related coronary artery do not achieve valid myocardial reperfusion (no-reflow phenomenon or coronary microvascular obstruction [MVO]). The mechanisms of MVO are incompletely understood. In this study we investigated the role platelet activation in the pathogenesis of coronary MVO in STEMI patients. ⋯ Platelet receptor expression, platelet receptor conformational change for fibrinogen binding availability and MPA formation were increased in STEMI patients with MVO compared to both STEMI patients with MR and stable CAD patients, both on admission and at one-month follow-up (p<0.05 for all). Among STEMI patients, platelet activation is greater in those who display coronary MVO, compared to those with MR, after successful PCI, both on admission and one month after STEMI, suggesting that enhanced platelet activation might be involved in the pathogenesis of MVO. The persistence of enhanced platelet activation despite double classical anti-platelet therapy suggests that new anti-platelet strategies should be considered in patients with coronary MVO.
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Intracranial haemorrhage (ICH), which affects up to 1% of patients on oral anticoagulation per year, is the most feared and devastating complication of this treatment. After such an event, it is unclear whether anticoagulant therapy should be resumed. Such a decision hinges upon the assessment of the competing risks of haematoma growth or recurrent ICH and thromboembolic events. ⋯ Patients with deep hemispheric ICH and a baseline risk of ischemic stroke >6.5% per year, that corresponds to CHADS2≥ 4 or CHA2DS2-VASc ≥ 5, may receive net benefit from restarting anticoagulation. To date, a reasonable recommendation regarding time to resumption of anticoagulation therapy would be after 10 weeks. Available data regarding the role of magnetic resonance imaging in assessing the risks of both ICH and warfarin-related ICH do not support the use of this test for excluding anticoagulation in patients with atrial fibrillation.
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Circulating microparticles play a pro-inflammatory and procoagulant detrimental role in the vascular dysfunction of septic shock. It was the objective of this study to investigate mechanisms by which a pharmacological modulation of microparticles could affect vascular dysfunction in a rat model of septic shock. Septic or sham rats were treated by activated protein C (aPC) and resuscitated during 4 hours. ⋯ In inoculated naïve recipients, microparticles from aPC-treated septic rats prompted reduced NF-κB and cyclooxygenase-2 arterial activation, blunted the generation of pro-inflammatory iNOS and secondarily increased platelet and endothelial microparticles. In conclusion, in this septic shock model, increased circulating levels of procoagulant microparticles led to negative haemodynamic outcomes. Pharmacological treatment by aPC modified the cell origin and levels of circulating microparticles, thereby limiting vascular inflammation and favouring haemodynamic improvement.