Oral anticoagulant treatment: risk factors involved in 500 intracranial hemorrhages

The role of anticoagulants, antiplatelet agents, and their reversal strategies in the management of intracerebral hemorrhage

New anticoagulant and antiplatelet medications have been approved and are prescribed with increased frequency. Intracranial hemorrhage is associated with the use of these medications. Therefore, neurosurgeons need to be aware of these new medications, how they are different from their predecessors, and the strategies for the urgent reversal of their effects. Utilization of intraluminal stents by endovascular neurosurgeons has resulted in the need to have a thorough understanding of antiplatelet agents. Increased use of dabigatran, rivaroxaban, and apixaban as oral anticoagulants for the treatment of atrial fibrillation and acute deep venous thrombosis has increased despite the lack of known antidotes to these medications.

PATCH: platelet transfusion in cerebral haemorrhage: study protocol for a multicentre, randomised, controlled trial

Background

Patients suffering from intracerebral haemorrhage have a poor prognosis, especially if they are using antiplatelet therapy. Currently, no effective acute treatment option for intracerebral haemorrhage exists. Limiting the early growth of intracerebral haemorrhage volume which continues the first hours after admission seems a promising strategy. Because intracerebral haemorrhage patients who are on antiplatelet therapy have been shown to be particularly at risk of early haematoma growth, platelet transfusion may have a beneficial effect.

Methods/Design

The primary objective is to investigate whether platelet transfusion improves outcome in intracerebral haemorrhage patients who are on antiplatelet treatment. The PATCH study is a prospective, randomised, multi-centre study with open treatment and blind endpoint evaluation. Patients will be randomised to receive platelet transfusion within six hours or standard care. The primary endpoint is functional health after three months. The main secondary endpoints are safety of platelet transfusion and the occurrence of haematoma growth. To detect an absolute poor outcome reduction of 20%, a total of 190 patients will be included.

Discussion

To our knowledge this is the first randomised controlled trial of platelet transfusion for an acute haemorrhagic disease.

Trial registration

The Netherlands National Trial Register (NTR1303)

Prevention and treatment of venous thromboembolism in older people

The incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE), collectively called venous thromboembolism (VTE), increases with age and has been reported to be higher in males. The annual incidence rates per 1000 for DVT and PE are 1.3 and 1.8, respectively, for people aged between 65 and 69 years, rising to 2.8 and 3.1, respectively, in those aged between 85 and 89 years. Older people are about eight times more likely to develop VTE in hospitals, nursing homes or other chronic care facilities than younger adults. About 1.7% develop PE within one year of treatment for DVT, whilst the one year recurrence rate for PE was 8.0%. About 3% of patients with DVT and 21% of those with PE die in hospital. One year mortality with DVT is 21% and that with PE is 39%.

Frequency of adverse events in patients with poor anticoagulation: a meta-analysis

BACKGROUND

Patients taking anticoagulants orally over the long term have international normalized ratios (INRs) outside the individual therapeutic range more than one-third of the time. Improved anticoagulation control will reduce hemorrhagic and thromboembolic event rates. To gauge the potential effect of improved anticoagulation control, we undertook to determine the proportion of anticoagulant-associated events that occur when INRs are outside the therapeutic range.

METHODS

We conducted a meta-analysis of all studies that assigned hemorrhagic and thromboembolic events in patients taking anticoagulants to discrete INR ranges. We identified studies using the MEDLINE (1966-2006) and EMBASE (1980-2006) databases. We included studies reported in English if the majority of patients taking oral anticoagulants had an INR range with a lower limit between 1.8 and 2 and an upper limit between 3 and 3.5, and their INR at the time of the hemorrhagic or thromboembolic event was recorded.

RESULTS

The final analysis included results from 45 studies (23 that reported both hemorrhages and thromboemboli; 14 that reported hemorrhages only; and 8, thromboemboli only) involving a median of 208 patients (limits of interquartile range [25th-75th percentile] 131-523 subjects; total n = 71 065). Of these studies, 64% were conducted at community practices; the remainder, at anticoagulation clinics. About 69% of the studies were classed as having moderate or high quality. Overall, 44% (95% confidence interval [CI] 39%-49%) of hemorrhages occurred when INRs were above the therapeutic range, and 48% (95% CI 41%-55%) of thromboemboli took place when below it. The mean proportion of events that occurred while the patient's INR was outside the therapeutic range was greater for studies with a short mean follow-up (< 1 yr). Between-study heterogeneity was significant (p < 0.001).

INTERPRETATION

Improved anticoagulation control could decrease the likelihood of almost half of all anticoagulant-associated adverse events.