Aniara | Shaping the Future with Innovative Solutions

New in Coagulation

Monday, March 6, 2017

What's New in Coagulation - March 2017

Written By Donna Castellone, MS, MT (ASCP) SH | LinkedIn

Want to be in the know? Check out our monthly compilation of the latest studies, guidelines, and discussions in coagulation.

Please note - many linked teasers require registered account/subscription in order to view the full articles. Medscape registration is free of charge.

Lower NOAC Doses Used Despite Lack of Data

In a commentary on a publication, Dr. Goldhaber discusses the use of lower dose oral anticoagulants reserved for patients with chronic kidney disease. This was done by a retrospective review of 3 years of patients (n=>300) records who were receiving dabigatran, rivaroxaban and apixaban. Indications for lower doses were found in 50% of these patients. Lower doses are prescribed to minimize bleeding risks, however it is not known if there is an increase in thrombotic complications. Several patients had comorbidities and this cohort of patients were not part of a randomized controlled study. This is a sicker population that may be at a higher risk for bleeding? There is a need for observational studies to obtain information from these population of patients.

Buzz, Prospects Build for Heparin-Induced Thrombocytopenia Test

Instrument Laboratory is releasing the Hemosil, HIT ab(PF4-H) automated assay for HIT. HIT is caused by antibodies to PF4 and heparin with a 20% mortality rate, and 50% having another morbidity. It is not common, and it occurs in 0.2-2% of patients on heparin, however heparin is one of the most commonly used drugs so it is an adverse drug effect. When a patient has a platelet count that drops 50% or more within 5-14 days HIT is suspected. Serotonin release assay is the gold standard and used as the confirmatory test, with a specificity of almost 100%. ELISA testing is the most commonly performed test, with a sensitivity of 99% but a specificity of 30-70%. There is no rapid test with sufficient sensitivity. Upon suspicion of HIT, a patient should be removed from all sources of heparin however alternative therapy- most commonly argatroban at a cost of $1000/day. Having a rapid test, can improve clinical outcomes while decreasing anticoagulant costs.

New Pre-Eclasmpsia Evidence Confirms Aspirin Guideline

In women with a history of pre-eclampsia, a 30% reduction can be seen with daily low dose aspirin. This affects 5-8% of pregnancies. It's cause is unclear but can be triggered by a combination of factors including genetics, maternal comorbidities and immunologic and endothelial mediators. There is an overproduction of thromboxane which contributes to vasoconstriction and platelet aggregation resulting in placental ischemia. As a result, aspirin with is vasodilation activity is a viable solution. Results of a study demonstrated a 49% reduction in risk. The risk and the cost is very low. The study is retrospective, aspirin has not been found to be beneficial in two large randomized trials. However combining results in a meta analysis showed some benefit.

NOACs Now Seen as Go-to Anticoagulants for New-Onset Atrial Fibrillation

A study from the Journal of American College of Cardiology suggests that NOACS have become the treatment of choice over vitamin K antagonists. Since the use of NOACS, 79.9% of patients received oral anticoagulants in which 47.6% were NOACS, versus 32.3% of VKA and 11.3% aspirin. While prior to NOACS, 32.8% received VKA, 41.7% aspirin and 20.2% no therapy. Of note is that aspirin is still being used in AF, but is not appropriate stroke prevention therapy.

Rivaroxaban Benefity in CAD, PAD Stops Huge Randominzed Trial

The COMPASS trial was stopped more than a year prior to completion due to the findings of superiority for the daily antithrombotic regimen using rivaroxaban versus aspirin in CAD or PAD. The trial had randomized 27,402 patients at hundreds of sites around the world to receive the direct oral anticoagulant (DOAC) rivaroxaban at 2.5 mg twice daily plus aspirin at 100 mg/day, or rivaroxaban 5 mg twice daily without aspirin, or aspirin 100 mg/day without rivaroxaban. Aspirin is a mainstay in this disorder and the change in therapy would be a major shift in practice.


Net Clinical Benefit of Warfarin in Individuals With Atrial Fibrillation Across Stroke Risk and Across Primary and Secondary Care

Victoria Allan; Amitava Banerjee; Anoop Dinesh Shah; Riyaz Patel; Spiros Denaxas; Juan-Pablo Casas; Harry Hemingway

Heart. 2017;103(3):210-218.

Abstract and Introduction<

Objective: To investigate net clinical benefit (NCB) of warfarin in individuals with atrial fibrillation (AF) across stroke risk and across primary and secondary care.

Methods: We conducted a linked electronic health record cohort study of 70 206 individuals with initial record of diagnosis of AF in primary (n=29 568) or secondary care (n=40 638) in England (1998-2010). We defined stroke risk according to the CHA2DS2-VASc score, and followed individuals over a median 2.2 years for 7005 ischaemic strokes (IS) and for 906 haemorrhagic strokes (HS). We calculated incidence rates (IRs) and 95% CIs per 100 person-years (PYs) (IR (95% CI)/100 PY) of IS and HS, with and without use of warfarin, and the NCB (ie, number of IS avoided) per 100 PYs of warfarin use (NCB (95% CI)/100 PY).

Results: Compared with individuals with initial record of diagnosis in secondary care, those in primary care had lower scores of IS risk (CHA2DS2-VASc≤2: 30.8% vs 20.6%), and lower overall incidence of IS (IR (95% CI)/100 PY: 2.3 (2.2 to 2.4) vs 4.3 (4.2 to 4.4), p value=0.00); however among individuals with CHA2DS2-VASc=0, 1 or 2 there were no differences in IS rate between those with initial record of diagnosis in primary care or secondary care (IR (95% CI)/100 PY: 0.2 (0.1 to 0.3) vs 0.3 (0.2 to 0.5), p value=0.16), (IR (95% CI)/100 PY: 0.6 (0.4 to 0.7) vs 0.7 (0.6 to 0.9), p value=0.08) and (IR (95% CI)/100 PY: 1.1 (1.00 to 1.3) vs 1.4 (1.2 to 1.6), p value=0.05), respectively. For CHA2DS2-VASc=0, 1 and 2, IRs of IS with versus without warfarin were (IR (95% CI)/100 PY: 0.4 (0.2 to 0.8) vs 0.2 (0.1 to 0.3), p value=0.16), (IR (95% CI)/100 PY: 0.4 (0.3 to 0.7) vs 0.7 (0.6 to 0.8), p value=0.03) and (IR (95% CI)/100 PY: 0.8 (0.7 to 1.0) vs 1.4 (1.3 to 1.6), p value=0.00), respectively. We found a significant positive NCB of warfarin from CHA2DS2-VASc≥2 in men (NCB (95% CI)/100 PY: 0.5 (0.1 to 0.9)) and from CHA2DS2-VASc≥3 in women (NCB (95% CI)/100 PY: 1.5 (1.1 to 1.9)).

Conclustions: CHA2DS2-VASc accurately stratifies IS risk in individuals with AF across both primary and secondary care. However, the incidence rate of ischaemic stroke at CHA2DS2-VASc=1 are lower than previously reported, which may change the decision to start anticoagulation with warfarin in these individuals.

Fibrinogen in the Initial Resuscitation of Severe Trauma (FiiRST)

A Randomized Feasibility Trial

B. Nascimento; J. Callum1, H. Tien; H. Peng; S. Rizoli; P. Karanicolas; A. Alam; W. Xiong; R. Selby; A-M. Garzon; C. Colavecchia; R. Howald; A. Nathens; A. Beckett
Br J Anaesth. 2016;117(6):775-782.

Abstract and Introduction

Background: Decreased plasma fibrinogen concentration shortly after injury is associated with higher blood transfusion needs and mortality. In North America and the UK, cryoprecipitate transfusion is the standard-of-care for fibrinogen supplementation during acute haemorrhage, which often occurs late during trauma resuscitation. Alternatively, fibrinogen concentrate (FC) can be beneficial in trauma resuscitation. However, the feasibility of its early infusion, efficacy and safety remain undetermined. The objective of this trial was to evaluate the feasibility, effect on clinical and laboratory outcomes and complications of early infusion of FC in trauma.

Methods: Fifty hypotensive (systolic arterial pressure ≤100 mm Hg) adult patients requiring blood transfusion were randomly assigned to either 6 g of FC or placebo, between Oct 2014 and Nov 2015 at a tertiary trauma centre. The primary outcome, feasibility, was assessed by the proportion of patients receiving the intervention (FC or placebo) within one h of hospital arrival. Plasma fibrinogen concentration was measured, and 28-day mortality and incidence of thromboembolic events were assessed.

Results: Overall, 96% (43/45) [95% CI 86-99%] of patients received the intervention within one h; 95% and 96% in the FC and placebo groups, respectively (P=1.00). Plasma fibrinogen concentrations remained higher in the FC group up to 12 h after admission with the largest difference at three h (2.9 mg dL -1 vs. 1.8 mg dL -1; P<0.01). The 28-day mortality and thromboembolic complications were similar between groups.

Conclusions: Early infusion of FC is feasible and increases plasma fibrinogen concentration during trauma resuscitation. Larger trials are justified.

Thromboprophylaxis in Atrial Fibrillation and Association With Cognitive Decline

Systematic Review

Peter Moffitt; Deirdre A. Lane; Helen Park; Janice O'Connell; Terence J. Quinn
Age Ageing. 2016;45(6):767-775.

Abstract and Introduction<

Objective: Atrial fibrillation (AF) is associated with dementia. If AF-related cognitive decline is driven by cerebral embolic events, thromboprophylaxis may impact on this. This systematic review assessed the association between cognitive impairment and AF thromboprophylaxis.

Methods: Two independent reviewers searched CINAHL, EMBASE, MEDLINE, PsycINFO, Web of Science Core Collection and Cochrane Library from inception until 12 November 2014. Eligible studies compared AF thromboprophylaxis to control with an outcome measure of cognition or dementia. Where data allowed, meta-analyses describing between-group differences in cognitive test scores or rates of incident dementia were performed.

Results: Nineteen studies were eligible. For two prospective studies (one randomised controlled trial, RCT) comparing anticoagulation against antiplatelet therapy, change in Mini-Mental Score Examination (MMSE) score from baseline to last follow-up (maximal duration: 5.9 years) suggested a difference favouring anticoagulation (mean difference: 0.90, 95% CI: 0.29-1.51), in keeping with a trend seen in the single RCT (mean difference MMSE: 0.80, 95% CI: -0.07 to 1.67). Pooled odds ratio (OR) suggested no association with incident dementia, comparing anticoagulant to antiplatelet therapy (two studies, OR: 1.23, 95% CI: 0.80-1.91) or no treatment (three studies, OR: 0.89, 95% CI: 0.47-1.69).

Conclusion: our analyses show no definitive evidence of cognitive benefit or harm from anticoagulation. We demonstrated a potential benefit of anticoagulation in comparison to antiplatelet over time. Larger scale studies with longer follow-up are needed to determine the true cognitive impact of AF thromboprophylaxis.


This website contains information on products which is targeted to a wide range of audiences and could contain product details or information otherwise not accessible or valid in your country. Please be aware that we do not take any responsibility for accessing such information which may not comply with any legal process, regulation, registration or usage in the country of your origin.