Intracerebral haemorrhage in patients taking different types of oral anticoagulants: a pooled individual patient data analysis from two national stroke registries

BACKGROUND

We investigated outcomes in patients with intracerebral haemorrhage (ICH) according to prior anticoagulation treatment with Vitamin K antagonists (VKAs), direct oral anticoagulants (DOACs) or no anticoagulation.

METHODS

This is an individual patient data study combining two prospective national stroke registries from Switzerland and Norway (2013-2019). We included all consecutive patients with ICH from both registries. The main outcomes were favourable functional outcome (modified Rankin Scale 0-2) and mortality at 3 months.

RESULTS

Among 11 349 patients with ICH (mean age 73.6 years; 47.6% women), 1491 (13.1%) were taking VKAs and 1205 (10.6%) DOACs (95.2% factor Xa inhibitors). The median percentage of patients on prior anticoagulation was 23.7 (IQR 22.6-25.1) with VKAs decreasing (from 18.3% to 7.6%) and DOACs increasing (from 3.0% to 18.0%) over time. Prior VKA therapy (n=209 (22.3%); adjusted ORs (aOR), 0.64; 95% CI, 0.49 to 0.84) and prior DOAC therapy (n=184 (25.7%); aOR, 0.64; 95% CI, 0.47 to 0.87) were independently associated with lower odds of favourable outcome compared with patients without anticoagulation (n=2037 (38.8%)). Prior VKA therapy (n=720 (49.4%); aOR, 1.71; 95% CI, 1.41 to 2.08) and prior DOAC therapy (n=460 (39.7%); aOR, 1.28; 95% CI, 1.02 to 1.60) were independently associated with higher odds of mortality compared with patients without anticoagulation (n=2512 (30.2%)).

CONCLUSIONS

The spectrum of anticoagulation-associated ICH changed over time. Compared with patients without prior anticoagulation, prior VKA treatment and prior DOAC treatment were independently associated with lower odds of favourable outcome and higher odds of mortality at 3 months. Specific reversal agents unavailable during the study period might improve outcomes of DOAC-associated ICH in the future.

Antithrombotic treatment after intracerebral hemorrhage: Surveys among stroke physicians in Scandinavia and the United Kingdom

Background and Aims

It is unclear whether patients with previous intracerebral hemorrhage (ICH) should receive antithrombotic treatment to prevent ischemic events. We assessed stroke physicians' opinions about this, and their views on randomizing patients in trials assessing this question.

Methods

We conducted three web-based surveys among stroke physicians in Scandinavia and the United Kingdom.

Results

Eighty-nine of 205 stroke physicians (43%) responded to the Scandinavian survey, 161 of 180 (89%) to the UK antiplatelet survey, and 153 of 289 (53%) to the UK anticoagulant survey. In Scandinavia, 19 (21%) stroke physicians were uncertain about antiplatelet treatment after ICH for ischemic stroke or transient ischemic attack (TIA) and 21 (24%) for prior myocardial infarction. In the United Kingdom, 116 (77%) were uncertain for ischemic stroke or TIA and 115 (717%) for ischemic heart disease. In Scandinavia, 32 (36%) were uncertain about anticoagulant treatment after ICH for atrial fibrillation, and 26 (29%) for recurrent deep vein thrombosis or pulmonary embolism. In the United Kingdom, 145 (95%) were uncertain about anticoagulants after ICH in at least some cases. In both regions combined, 191 of 250 (76%) would consider randomizing ICH survivors in a trial of starting versus avoiding antiplatelets, and 176 of 242 (73%) in a trial of starting versus avoiding anticoagulants.

Conclusion

Considerable proportions of stroke physicians in Scandinavia and the United Kingdom were uncertain about antithrombotic treatment after ICH. A clear majority would consider randomizing patients in trials assessing this question. These findings support the need for such trials.

STudy of Antithrombotic Treatment after IntraCerebral Haemorrhage: Protocol for a randomised controlled trial

Background and aims

Many patients with prior intracerebral haemorrhage have indications for antithrombotic treatment with antiplatelet or anticoagulant drugs for prevention of ischaemic events, but it is uncertain whether such treatment is beneficial after intracerebral haemorrhage. STudy of Antithrombotic Treatment after IntraCerebral Haemorrhage will assess (i) the effects of long-term antithrombotic treatment on the risk of recurrent intracerebral haemorrhage and occlusive vascular events after intracerebral haemorrhage and (ii) whether imaging findings, like cerebral microbleeds, modify these effects.

Methods

STudy of Antithrombotic Treatment after IntraCerebral Haemorrhage is a multicentre, randomised controlled, open trial of starting versus avoiding antithrombotic treatment after non-traumatic intracerebral haemorrhage, in patients with an indication for antithrombotic treatment. Participants with vascular disease as an indication for antiplatelet treatment are randomly allocated to antiplatelet treatment or no antithrombotic treatment. Participants with atrial fibrillation as an indication for anticoagulant treatment are randomly allocated to anticoagulant treatment or no anticoagulant treatment. Cerebral CT or MRI is performed before randomisation. Duration of follow-up is at least two years. The primary outcome is recurrent intracerebral haemorrhage. Secondary outcomes include occlusive vascular events and death. Assessment of clinical outcomes is performed blinded to treatment allocation. Target recruitment is 500 participants.

Trial status: Recruitment to STudy of Antithrombotic Treatment after IntraCerebral Haemorrhage is on-going. On 30 April 2020, 44 participants had been enrolled in 31 participating hospitals. An individual patient–data meta-analysis is planned with similar randomised trials.

Antithrombotic treatment after stroke due to intracerebral haemorrhage

BACKGROUND

Survivors of stroke due to intracerebral haemorrhage (ICH) are at risk of thromboembolism. Antithrombotic (antiplatelet or anticoagulant) treatments may lower the risk of thromboembolism after ICH, but they may increase the risks of bleeding.

OBJECTIVES

To determine the overall effectiveness and safety of antithrombotic drugs for people with ICH.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (24 March 2017). We also searched the Cochrane Central Register of Controlled Trials (CENTRAL: the Cochrane Library 2017, Issue 3), MEDLINE Ovid (from 1948 to March 2017), Embase Ovid (from 1980 to March 2017), and online registries of clinical trials (8 March 2017). We also screened the reference lists of included trials for additional, potentially relevant studies.

SELECTION CRITERIA

We selected all randomised controlled trials (RCTs) of any antithrombotic treatment after ICH.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data. We converted categorical estimates of effect to the risk ratio (RR) or odds ratio (OR), as appropriate. We divided our analyses into short- and long-term treatment, and used fixed-effect modelling for meta-analyses. Three review authors independently assessed the included RCTs for risks of bias and we created a 'Summary of findings' table using GRADE.

MAIN RESULTS

We included two RCTs with a total of 121 participants. Both RCTs were of short-term parenteral anticoagulation early after ICH: one tested heparin and the other enoxaparin. The risk of bias in the included RCTs was generally unclear or low, with the exception of blinding of participants and personnel, which was not done. The included RCTs did not report our chosen primary outcome (a composite outcome of all serious vascular events including ischaemic stroke, myocardial infarction, other major ischaemic event, ICH, major extracerebral haemorrhage, and vascular death). Parenteral anticoagulation did not cause a statistically significant difference in case fatality (RR 1.25, 95% confidence interval (CI) 0.38 to 4.07 in one RCT involving 46 participants, low-quality evidence), ICH, or major extracerebral haemorrhage (no detected events in one RCT involving 75 participants, low-quality evidence), growth of ICH (RR 1.64, 95% CI 0.51 to 5.29 in two RCTs involving 121 participants, low-quality evidence), deep vein thrombosis (RR 0.99, 95% CI 0.49 to 1.96 in two RCTs involving 121 participants, low quality evidence), or major ischaemic events (RR 0.54, 95% CI 0.23 to 1.28 in two RCTs involving 121 participants, low quality evidence).

AUTHORS' CONCLUSIONS

There is insufficient evidence from RCTs to support or discourage the use of antithrombotic treatment after ICH. RCTs comparing starting versus avoiding antiplatelet or anticoagulant drugs after ICH appear justified and are needed in clinical practice.

Blinded trials taken to the test: an analysis of randomized clinical trials that report tests for the success of blinding

BACKGROUND

Blinding can reduce bias in randomized clinical trials, but blinding procedures may be unsuccessful. Our aim was to assess how often randomized clinical trials test the success of blinding, the methods involved and how often blinding is reported as being successful.

METHODS

We analysed a random sample of blinded randomized clinical trials indexed in the The Cochrane Central Register of Controlled Trials and published in 2001. We identified 1599 blinded trials, and noted if they had conducted any test for the success of blinding. We also selected 200 trials randomly that did not report any such test, and sent a questionnaire to the corresponding authors asking them if they had conducted any tests.

RESULTS

Thirty-one out of 1599 trials (2%) reported tests for the success of blinding. Test methods varied, and reporting was generally incomplete. Blinding was considered successful in 14 out of the 31 trials (45%) and unclear in 10 (32%). Of the seven trials (23%) reporting unsuccessful blinding the risk of a biased trial result was either not addressed or was discounted in six cases. We received 130 questionnaires from trial authors (65%) of which 15 (12%) informed that they had conducted, but not published, tests.

CONCLUSIONS

Blinding is rarely tested. Test methods vary, and the reporting of tests, and test results, is incomplete. There is a considerable methodological uncertainty how best to assess blinding, and an urgent need for improved methodology and improved reporting.

Comparison of descriptions of allocation concealment in trial protocols and the published reports: cohort study

OBJECTIVES

To compare how allocation concealment is described in publications of randomised clinical trials and corresponding protocols, and to estimate how often trial publications with unclear allocation concealment have adequate concealment according to the protocol.

DESIGN

Cohort study of 102 sets of trial protocols and corresponding publications.

SETTING

Protocols of randomised trials approved by the scientific and ethical committees for Copenhagen and Frederiksberg, 1994 and 1995.

MAIN OUTCOME MEASURES

Frequency of adequate, unclear, and inadequate allocation concealment and sequence generation in trial publications compared with protocols, and the proportion of protocols where methods were reported to be adequate but descriptions were unclear in the trial publications.

RESULTS

96 of the 102 trials had unclear allocation concealment according to the trial publication. According to the protocols, 15 of these 96 trials had adequate allocation concealment (16%, 95% confidence interval 9% to 24%), 80 had unclear concealment (83%, 74% to 90%), and one had inadequate concealment. When retrospectively defined loose criteria for concealment were applied, 83 of the 102 trial publications had unclear concealment. According to their protocol, 33 of these 83 trials had adequate allocation concealment (40%, 29% to 51%), 49 had unclear concealment (59%, 48% to 70%), and one had inadequate concealment.

CONCLUSIONS

Most randomised clinical trials have unclear allocation concealment on the basis of the trial publication alone. Most of these trials also have unclear allocation concealment according to their protocol.