Risk of intracerebral haemorrhage in Chinese patients with atrial fibrillation on warfarin with cerebral microbleeds: the IPAAC-Warfarin study

Risk of intracranial hemorrhage in patients using anticoagulant therapy for atrial fibrillation after cerebral microbleeds combined with acute ischemic stroke: a meta-analysis

Objective

To evaluate intracerebral hemorrhage (ICH) risk in patients with ischemic stroke (IS) and cerebral microbleeds (CMBs) undergoing anticoagulation therapy for non-valvular atrial fibrillation (AF).

Methods

We conducted a comprehensive search across multiple databases, including Embase, PubMed, Cochrane, UpToDate, Scopus, WOS, and SinoMed. The search covered observational literature published from each database inception until February 1, 2023. We analyzed the prevalence of CMBs during the follow-up period, compared future ICH risk between patients with and without baseline CMBs (CMBs presence/absence, ≧5 CMBs), and examined factors influencing ICH occurrence in patients with CMBs. Also studied recurrent stroke during anticoagulation therapy, the risk of future ICH when white matter hyperintensity (WMH) and CMBs coexist, and the effects of anticoagulants vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) on future ICH.

Results

We included 7 articles involving 5,134 participants. The incidence of CMBs was 24%; baseline CMBs were associated with an increased ICH risk compared to patients without CMBs. ICH-risk was more significant in patients with baseline ≥5 CMBs. After anticoagulant therapy, ICH risk was higher than that of recurrent IS. The risk of future ICH was significantly increased with anticoagulant VKAs compared with NOAC.

Conclusion

Anticoagulant therapy for ischemic stroke patients with non-valvular AF and CMBs increases future ICH risk. Discontinuing anticoagulation due to ICH risk should be avoided. NOACs are safe and effective for patients with CMBs and IS.

Combined effect of cortical superficial siderosis and cerebral microbleed on short-term and long-term outcomes after intracerebral haemorrhage

BACKGROUND AND PURPOSE

Cortical superficial siderosis (cSS) and cerebral microbleed (CMB) have distinct effects on intracerebral haemorrhage (ICH). We aim to investigate the combined effect of cSS and CMB on outcomes after ICH.

METHODS

Based on a single-centre stroke registry database, patients with spontaneous ICH who had CT scan within 48 hours after ictus and MRI subsequently were identified. Eligible patients were divided into four groups (cSS-CMB-, cSS-CMB+, cSS+CMB-, cSS+CMB+) according to cSS and CMB on susceptibility-weighted image of MRI. Primary outcomes were haematoma volume on admission and unfavourable outcome defined as modified Rankin Scale scores ≥3 at 3 months. Secondary outcomes were all-cause death, recurrence of stroke and ICH during follow-up (median follow-up 2.0 years, IQR 1.0-3.0 years).

RESULTS

A total of 673 patients were identified from 1044 patients with spontaneous ICH. 131 (19.5%) had cSS and 468 (69.5%) had CMB. Patients with cSS+CMB+ had the highest rate of poor outcome at 3 months, as well as all-cause death, recurrent stroke and ICH during follow-up. In cSS- patients, CMB was associated with smaller haematoma (β -0.13; 95% CI -0.22 to -0.03; p=0.009), but it still increased risks of recurrent ICH (OR 4.6; 95% CI 1.3 to 15.6; p=0.015) and stroke (OR 2.0; 95% CI 1.0 to 4.0; p=0.049). These effects of CMB became unremarkable in the context of cSS+.

CONCLUSIONS

Patients with different combinations of cSS and CMB have distinct patterns of short-term and long-term outcomes. Although CMB is related to restrained haematoma, it does not improve long-term outcomes.

TRIAL REGISTRATION NUMBER

NCT04803292.

Impact of Cerebral Microbleeds in Stroke Patients with Atrial Fibrillation

OBJECTIVES

Cerebral microbleeds are associated with the risks of ischemic stroke and intracranial hemorrhage, causing clinical dilemmas for antithrombotic treatment decisions. We aimed to evaluate the risks of intracranial hemorrhage and ischemic stroke associated with microbleeds in patients with atrial fibrillation treated with vitamin K antagonists, direct oral anticoagulants, antiplatelets, and combination therapy (i.e. concurrent oral anticoagulant and antiplatelet).

METHODS

We included patients with documented atrial fibrillation from the pooled individual patient data analysis by the Microbleeds International Collaborative Network. Risks of subsequent intracranial hemorrhage and ischemic stroke were compared between patients with and without microbleeds, stratified by antithrombotic use.

RESULTS

A total of 7,839 patients were included. The presence of microbleeds was associated with an increased relative risk of intracranial hemorrhage (adjusted hazard ratio [aHR] = 2.74, 95% confidence interval = 1.76-4.26) and ischemic stroke (aHR = 1.29, 95% confidence interval = 1.04-1.59). For the entire cohort, the absolute incidence of ischemic stroke was higher than intracranial hemorrhage regardless of microbleed burden. However, for the subgroup of patients taking combination of anticoagulant and antiplatelet therapy, the absolute risk of intracranial hemorrhage exceeded that of ischemic stroke in those with 2 to 4 microbleeds (25 vs 12 per 1,000 patient-years) and ≥ 11 microbleeds (94 vs 48 per 1,000 patient-years).

INTERPRETATION

Patients with atrial fibrillation and high burden of microbleeds receiving combination therapy have a tendency of higher rate of intracranial hemorrhage than ischemic stroke, with potential for net harm. Further studies are needed to help optimize stroke preventive strategies in this high-risk group. ANN NEUROL 2023;94:61-74.

Role of cerebral microbleeds in acute ischemic stroke and atrial fibrillation

Cerebral microbleeds (CMBs) are commonly detected in the brains of patients with acute ischemic stroke (AIS). With the development of neuroimaging, clinicians are paying more attention to the presence of CMBs. CMBs were found to significantly increase the risk of intracranial hemorrhagic transformation and hemorrhage in patients with AIS, especially in patients with concurrent atrial fibrillation (AF). Additionally, the presence of CMBs is thought to be a symbol of a high risk of recurrent ischemic stroke (IS). A few researchers have found that the presence of CMBs has no significant effect on the prognosis of patients with AIS. Therefore, the current views on the role of CMBs in the prognoses of patients with IS are controversial. The use of anticoagulants and other drugs has also become a dilemma due to the special influence of CMBs on the prognosis of these patients. Due to the large number of patients with AF and CMBs, many studies have been conducted on the effects of CMBs on these patients and subsequent pharmacological treatments. However, at present, there are no relevant guidelines to guide the secondary preventive treatment of patients with stroke, CMBs, and AF. In this paper, we summarized the role of CMBs in AIS combined with AF and relevant preventive measures against the recurrence of stroke and the occurrence of intracerebral hemorrhage to help clarify the specifics of drug therapies for this group of patients.

Epidemiology of cerebral microbleeds and risk of adverse outcomes in atrial fibrillation: a systematic review and meta-analysis

AIMS

The aim of this study is to perform a systematic review and meta-analysis on the epidemiology of cerebral microbleeds (CMBs) and the risk of intracranial haemorrhage (ICH) and ischaemic stroke (IS) in patients with atrial fibrillation (AF).

METHODS AND RESULTS

PubMed and EMBASE databases were systematically searched from inception to 6 March 2021. All studies reporting the prevalence of CMBs and incidence of ICH and IS in AF patients with and without CMBs were included. Meta-analysis was conducted using random-effect models; odds ratios (ORs), 95% confidence intervals (CIs), and prediction intervals (PIs) were calculated for each outcome. Subgroup analyses were performed according to the number and localization of CMBs. A total of 562 studies were retrieved, with 17 studies finally included in the meta-analysis. Prevalence of CMBs in AF population was estimated at 28.3% (95% CI: 23.8-33.4%). Individuals with CMBs showed a higher risk of ICH (OR: 3.04, 95% CI: 1.83-5.06, 95% PI 1.23-7.49) and IS (OR: 1.78, 95% CI: 1.26-2.49, 95% PI 1.10-2.87). Patients with ≥5 CMBs showed a higher risk of ICH. Metaregression showed how higher of prevalence of diabetes mellitus in AF cohort is associated with higher prevalence of CMBs.

CONCLUSIONS

Cerebral microbleeds are common in patients with AF, found in almost one out of four subjects. Cerebral microbleeds were associated with both haemorrhagic and thromboembolic events in AF patients. Moreover, the risk of ICH increased consistently with the burden of CMBs. Cerebral microbleeds may represent an important overlooked risk factor for both ICH and IS in adults with AF.

New cerebral microbleeds in AF patients on non-vitamin K oral anticoagulants or warfarin: One-year follow-up

Anticoagulant treatment increases the risk of intracerebral hemorrhage (ICH), but whether the treatment, more specifically non-vitamin K oral anticoagulants (NOACs), increases the risk of cerebral microbleeds (CMBs) remains uncertain. We performed this study to investigate the development of new CMBs due to NOACs or warfarin treatment in patients with atrial fibrillation (AF).We prospectively recruited AF patients before anticoagulation from June 2016 to June 2018. We performed susceptibility-weighted imaging (SWI) examinations on all enrolled AF patients and re-examined SWI 1 year later. We compared demographic features and new CMBs between the NOACs group and the warfarin group. Univariate analysis of clinical factors was performed according to the development of new CMBs; and age, a HAS-B(L)ED score, warfarin use, and the presence of baseline CMBs were then selected for inclusion in the multivariate logistic regression model.A total of 72 AF patients were recruited, 29 of whom were assigned to the NOACs group and 43 to the warfarin group. Finally, 1 patient in the NOACs group (3.4%) and 9 patients (20.9%) in the warfarin group developed new CMBs after 1 year follow-up (P = .08). Univariate analysis showed that age, a HAS-B(L)ED score ≥4, the presence of baseline CMBs were associated with the development of new CMBs (P < .05). And multivariate regression analysis showed baseline CMBs (P = .03, odds ratio = 6.37, 95% confidence interval 1.15-35.36) was independently related to the increase in new CMBs.AF patients treated with NOACs may have a decreased trend in the development of new CMBs compared with those treated with warfarin. Baseline CMBs increased the frequency of new CMBs during anticoagulant treatment. The development of new CMBs in AF patients with anticoagulation requires further longitudinal studies with longer follow-up in larger samples.

Microbleeds and Outcome in Patients With Acute Ischemic Stroke and Atrial Fibrillation Taking Anticoagulants

Background and Purpose:

We investigated the impact of the presence, burden, and location of cerebral microbleeds (CMBs) on the risk of major adverse cerebrovascular and cardiovascular events (MACCE) in patients with acute ischemic stroke and atrial fibrillation treated with oral anticoagulants (OACs). We also examined whether the clinical effect of CMBs differs according to the type of OACs.

Methods:

A total of 1742 patients with acute ischemic stroke and atrial fibrillation treated with OACs were enrolled in this cohort study. The primary composite outcome was the occurrence of MACCE (a composite of stroke, acute myocardial infarction, or vascular death) over a 2-year period according to CMB status.

Results:

CMB presence was significantly associated with the risk of future MACCE (hazard ratio, 1.89 [95% CI, 1.23–2.88]; P =0.003) after adjustment for confounders in patients with acute ischemic stroke and atrial fibrillation taking OACs. Patients with exactly 1 CMB had a similar rate of MACCE compared with those without CMBs ( P =0.461). However, patients with multiple CMBs (≥2), particularly high burden CMBs (≥5), had a significantly higher proportion of MACCE. Both CMB-positive groups with lobar and deep CMB had more frequent MACCE than the CMB-negative group, and the rate of MACCE was not different according to CMB location. In patients treated with warfarin, CMB was significantly associated with a risk of MACCE ( P =0.002), but not in patients treated with direct OACs ( P =0.517).

Conclusions:

The study results indicate that the risk of future MACCE increased with increasing CMB burden in patients with AIS and atrial fibrillation taking OACs, while the anatomic location of CMBs did not influence the risk of future MACCE. This risk seemed to be more apparent in patients taking warfarin.

Oral anticoagulant use and the development of new cerebral microbleeds in cardioembolic stroke patients with atrial fibrillation

OBJECTIVE

Cerebral microbleeds (CMBs) are a magnetic resonance imaging (MRI) marker for cerebral small vessel disease. Existing CMBs and those that newly develop are associated with the risks of stroke incidence and recurrence. The purpose of the present study was to investigate the association of oral anticoagulant (OAC) use and the development of new CMBs in cardioembolic stroke patients with atrial fibrillation.

SUBJECTS AND METHODS

We prospectively followed cardioembolic stroke patients with atrial fibrillation who had been hospitalized in the stroke center of our hospital, had been prescribed anticoagulants at discharge, and underwent repeated brain MRI with an interval of at least one year from the baseline MRI. Assessing the presence, number and location of CMBs using T2*-weighted gradient-recalled echo MRI, we used logistic regression models to investigate the associations between OAC use and the incidence of new CMBs. We also examined associations of subsequent stroke with OACs and CMBs during the follow-up.

RESULTS

A total of 81 patients, consisting of 45 patients receiving direct oral anticoagulants (DOACs) and 36 patients receiving warfarin (WF), were analyzed in the present study. Baseline CMBs were observed in 19/81 patients (23.5%) and new CMBs in 18/81 patients (22.2%) on follow-up MRI (median interval, 34 months). Of the 31 new CMBs, 25 (80.6%) developed in the lobar location and 6 (19.4%) in the deep or infratentorial location. New CMBs occurred in 4 patients (10.0%) taking DOACs　alone, in 10 patients (35.7%) taking WF alone, in 3 patients (37.5%) taking WF plus antiplatelet agents and in 1 patient (20.0%) taking DOAC plus antiplatelet agent. Regarding location, the new CMBs were the lobar type in 7 of the 10 patients taking WF alone, as well as in 3 of the 4 patients taking DOACs alone. In multivariate analysis, the presence of CMBs at baseline and WF use (vs. DOAC use) were associated with new CMBs (CMB presence at baseline: OR 4.16, 95% CI 1.19-14.44; WF use: OR 3.38, 95% CI 1.02-11.42). The presence of ≥ 2 CMBs at baseline was related to a higher risk of subsequent stroke (OR 7.25, 95% CI 1.01-52.35, P = 0.048).

CONCLUSION

Our findings suggest that DOAC compared with WF use at discharge is associated with a lower incidence of new CMBs in cardioembolic stroke patients with atrial fibrillation. Further prospective studies in the clinical setting are needed to confirm our exploratory data.

Intracerebral haemorrhage, microbleeds and antithrombotic drugs

Antithrombotic therapy is a cornerstone for secondary prevention of ischaemic events, cerebral and extra-cerebral. A number of clinical questions remain unanswered concerning the impact of antithrombotic drugs on the risk of first-ever and recurrent macro or micro cerebral haemorrhages, raising the clinical dilemma on the risk/benefit balance of giving antiplatelets and anticoagulants in patients with potential high risk of brain bleeds. High field magnetic resonance imaging (MRI) blood-weighted sequences, including susceptibility weighted imaging (SWI), have expanded the spectrum of these clinical questions, because of their increasing sensitivity in detecting radiological markers of small vessel disease. This review will summarise the literature, focusing on four main clinical questions: how do cerebral microbleeds impact the risk of cerebrovascular events in healthy patients, in patients with previous ischaemic stroke or transient ischaemic attack, and in patients with intracerebral haemorrhage? Is the risk/benefit balance of oral anticoagulants shifted by the presence of microbleeds in patients with atrial fibrillation after recent ischaemic stroke or transient ischaemic attack? Should we restart antiplatelet drugs after symptomatic intracerebral haemorrhage or not? Are oral anticoagulants allowed in patients with a history of atrial fibrillation and previous intracerebral haemorrhage?

Use of anticoagulant therapy and cerebral microbleeds: a systematic review and meta-analysis

BACKGROUND

Anticoagulant therapy increases the risk that cerebral microbleeds (CMBs) progress to intracerebral hemorrhage, but whether the therapy increases risk of CMB occurrence is unclear. We performed a systematic review and meta-analysis to investigate the potential association between anticoagulant use and CMB occurrence in stroke and stroke-free individuals.

METHODS

We searched observational studies in PubMed, Ovid EMBASE, and Cochrane Library from their inception until September 2019. We calculated the pooled odds ratio (OR) and 95% confidence interval (CI) for the prevalence and incidence of CMBs in anticoagulant users relative to non-anticoagulant users.

RESULTS

Forty-seven studies with 25,245 participants were included. The pooled analysis showed that anticoagulant use was associated with CMB prevalence (OR 1.54, 95% CI 1.26-1.88). The association was observed in subgroups stratified by type of participants: stroke-free, OR 1.86, 95% CI 1.25-2.77; ischemic stroke/transient ischemic attack, OR 1.33, 95% CI 1.06-1.67; and intracerebral hemorrhage, OR 2.26, 95% CI 1.06-4.83. Anticoagulant use was associated with increased prevalence of strictly lobar CMBs (OR 1.68, 95% CI 1.22-2.32) but not deep/infratentorial CMBs. Warfarin was associated with increased CMB prevalence (OR 1.64, 95% CI 1.23-2.18), but novel oral anticoagulants were not. Anticoagulant users showed higher incidence of CMBs during long-term follow-up (OR 1.72, 95% CI 1.22-2.44).

CONCLUSION

Anticoagulant use is associated with higher prevalence and incidence of CMBs. This association appears to depend on location of CMBs and type of anticoagulants. More longitudinal investigations with adjustment for confounders are required to establish the causality.

Cerebral microbleeds and stroke risk after ischaemic stroke or transient ischaemic attack: a pooled analysis of individual patient data from cohort studies

BACKGROUND

Cerebral microbleeds are a neuroimaging biomarker of stroke risk. A crucial clinical question is whether cerebral microbleeds indicate patients with recent ischaemic stroke or transient ischaemic attack in whom the rate of future intracranial haemorrhage is likely to exceed that of recurrent ischaemic stroke when treated with antithrombotic drugs. We therefore aimed to establish whether a large burden of cerebral microbleeds or particular anatomical patterns of cerebral microbleeds can identify ischaemic stroke or transient ischaemic attack patients at higher absolute risk of intracranial haemorrhage than ischaemic stroke.

METHODS

We did a pooled analysis of individual patient data from cohort studies in adults with recent ischaemic stroke or transient ischaemic attack. Cohorts were eligible for inclusion if they prospectively recruited adult participants with ischaemic stroke or transient ischaemic attack; included at least 50 participants; collected data on stroke events over at least 3 months follow-up; used an appropriate MRI sequence that is sensitive to magnetic susceptibility; and documented the number and anatomical distribution of cerebral microbleeds reliably using consensus criteria and validated scales. Our prespecified primary outcomes were a composite of any symptomatic intracranial haemorrhage or ischaemic stroke, symptomatic intracranial haemorrhage, and symptomatic ischaemic stroke. We registered this study with the PROSPERO international prospective register of systematic reviews, number CRD42016036602.

FINDINGS

Between Jan 1, 1996, and Dec 1, 2018, we identified 344 studies. After exclusions for ineligibility or declined requests for inclusion, 20 322 patients from 38 cohorts (over 35 225 patient-years of follow-up; median 1·34 years [IQR 0·19-2·44]) were included in our analyses. The adjusted hazard ratio [aHR] comparing patients with cerebral microbleeds to those without was 1·35 (95% CI 1·20-1·50) for the composite outcome of intracranial haemorrhage and ischaemic stroke; 2·45 (1·82-3·29) for intracranial haemorrhage and 1·23 (1·08-1·40) for ischaemic stroke. The aHR increased with increasing cerebral microbleed burden for intracranial haemorrhage but this effect was less marked for ischaemic stroke (for five or more cerebral microbleeds, aHR 4·55 [95% CI 3·08-6·72] for intracranial haemorrhage vs 1·47 [1·19-1·80] for ischaemic stroke; for ten or more cerebral microbleeds, aHR 5·52 [3·36-9·05] vs 1·43 [1·07-1·91]; and for ≥20 cerebral microbleeds, aHR 8·61 [4·69-15·81] vs 1·86 [1·23-1·82]). However, irrespective of cerebral microbleed anatomical distribution or burden, the rate of ischaemic stroke exceeded that of intracranial haemorrhage (for ten or more cerebral microbleeds, 64 ischaemic strokes [95% CI 48-84] per 1000 patient-years vs 27 intracranial haemorrhages [17-41] per 1000 patient-years; and for ≥20 cerebral microbleeds, 73 ischaemic strokes [46-108] per 1000 patient-years vs 39 intracranial haemorrhages [21-67] per 1000 patient-years).

INTERPRETATION

In patients with recent ischaemic stroke or transient ischaemic attack, cerebral microbleeds are associated with a greater relative hazard (aHR) for subsequent intracranial haemorrhage than for ischaemic stroke, but the absolute risk of ischaemic stroke is higher than that of intracranial haemorrhage, regardless of cerebral microbleed presence, antomical distribution, or burden.

FUNDING

British Heart Foundation and UK Stroke Association.