Cerebral Microbleeds in Ischemic Stroke Patients on Warfarin Treatment

Cerebral Microbleeds and Antiplatelet Therapy in Mongolian and Han Patients with Ischemic Cerebrovascular Disease

Objective

To analyze the differences in cerebral microbleeds (CMBs) and their correlation with intracerebral hemorrhage (ICH) in Mongolian and Han Chinese patients with ischemic cerebrovascular disease.

Methods

A total of 160 patients with ischemic cerebrovascular disease who took aspirin or clopidogrel for over one year were retrospectively analyzed, including 80 Mongolian and 80 han patients. The incidence, number, and distribution of CMBs were compared between groups. Logistic regression was used to identify risk factors for the occurrence of cerebral hemorrhage.

Results

The detection rate of CMBs was significantly lower in Mongolian patients compared to Han patients (P = 0.040). Mongolian patients had a higher distribution of CMBs in the deep or infratentorial regions (66.6% vs 58.1%), while Han patients had a higher lobar distribution (P = 0.007). Prolonged antiplatelet therapy (over 3 years) was a risk factor for CMB development in both groups and was also linked to an increased risk of ICH. Patients with a higher number of CMBs had a greater likelihood of experiencing ICH.

Conclusion

Mongolian patients had a lower likelihood of developing CMBs than Han patients, but with a higher deep or infratentorial distribution. The presence of CMBs, especially with long-term antiplatelet therapy, is a significant predictor of ICH. No significant difference in ICH risk was found between ethnic groups. Close monitoring of patients with CMBs during prolonged antiplatelet therapy is crucial to reduce hemorrhagic events.

Cerebral microbleeds in acute ischemic stroke after intravenous thrombolysis and their impact on short term outcome of stroke

OBJECTIVES

Strong evidence suggests the occurrence of cerebral microbleeds (CMBs) in 5-13% of stroke patients within the first week after stroke onset. The aim of this work was to study risk factors associated with occurrence of CMBs in patients with stroke who received intravenous thrombolysis, and to clarify their impact on the clinical outcome.

METHODS

This prospective observational study was conducted on 61 acute ischemic stroke patients eligible for treatment with recombinant tissue plasminogen activator (rt-PA). Assessment of stroke-related neurologic deficit was done using National Institute of Health Stroke Scale (NIHSS). Assessment of stroke related disability after 3 months from stroke onset was done using Modified Rankin Scale (mRS). CMBs were detected by T2*-weighed gradient-recalled echo (T2*-GRE) and susceptibility-weighted imaging (SWI) magnetic resonance imaging (MRI) sequences.

RESULTS

There was a statistically significant impact of age, mean arterial pressure (MAP) at stroke onset, history of hypertension (HTN), and white matter changes assessed by Fazekas scale on the occurrence of CMBs in the included stroke patients (P-value= 0.002, <0.001, <0.001, 0.008 respectively). There was no statistically significant difference between patients with favorable and those with unfavorable outcome regarding the total number of CMBs (P-value =0.542). There was also no statistically significant difference between patients who developed complications from rt-PA and those who didn't develop regarding the total number of CMBs (P-value =0.186).

CONCLUSION

Cerebral microbleeds are more likely to occur in older stroke patients and in those who had high MAP at stroke onset, history of HTN, and white matter changes.

Prevalence and Impact of Cerebral Microbleeds on Clinical and Safety Outcomes in Acute Ischaemic Stroke Patients Receiving Reperfusion Therapy: A Systematic Review and Meta-Analysis

BACKGROUND

Cerebral microbleeds (CMBs), a notable neuroimaging finding often associated with cerebral microangiopathy, demonstrate a heightened prevalence in patients diagnosed with acute ischemic stroke (AIS), which is in turn linked to less favourable clinical prognoses. Nevertheless, the exact prevalence of CMBs and their influence on post-reperfusion therapy outcomes remain inadequately elucidated.

MATERIALS AND METHODS

Through systematic searches of PubMed, Embase and Cochrane databases, studies were identified adhering to specific inclusion criteria: (a) AIS patients, (b) age ≥ 18 years, (c) CMBs at baseline, (d) availability of comparative data between CMB-positive and CMB-negative groups, along with relevant post-reperfusion therapy outcomes. The data extracted were analysed using forest plots of odds ratios, and random-effects modelling was applied to investigate the association between CMBs and symptomatic intracerebral haemorrhage (sICH), haemorrhagic transformation (HT), 90-day functional outcomes, and 90-day mortality post-reperfusion therapy.

RESULTS

In a total cohort of 9776 AIS patients who underwent reperfusion therapy, 1709 had CMBs, with a pooled prevalence of 19% (ES 0.19; 95% CI: 0.16, 0.23, p < 0.001). CMBs significantly increased the odds of sICH (OR 2.57; 95% CI: 1.72; 3.83; p < 0.0001), HT (OR 1.53; 95% CI: 1.25; 1.88; p < 0.0001), as well as poor functional outcomes at 90 days (OR 1.59; 95% CI: 1.34; 1.89; p < 0.0001) and 90-day mortality (OR 1.65; 95% CI: 1.27; 2.16; p < 0.0001), relative to those without CMBs, in AIS patients undergoing reperfusion therapy (encompassing intravenous thrombolysis [IVT], endovascular thrombectomy [EVT], either IVT or EVT, and bridging therapy). Variations in the level of association can be observed among different subgroups of reperfusion therapy.

CONCLUSIONS

This meta-analysis underscores a significant association between CMBs and adverse postprocedural safety outcomes encompassing sICH, HT, poor functional outcome, and increased mortality in AIS patients undergoing reperfusion therapy. The notable prevalence of CMBs in both the overall AIS population and those undergoing reperfusion therapy emphasizes their importance in post-stroke prognostication.

Warfarin-induced isolated spontaneous subarachnoid hemorrhage: Rare case report

Introduction and importance

Subarachnoid hemorrhage (SAH) is mostly associated with head trauma. Non-traumatic subarachnoid hemorrhage is mostly due to vascular abnormalities: either hemorrhage from ruptured aneurysm or bleeding from arteriovenous malformation. Aneurysmal hemorrhage is the biggest cause in non-traumatic cases. Warfarin is associated with cerebral intraparenchymal hemorrhage, but it is rarely associated with SAH.

Case presentation

Here, we report the case of a 45-year-old male patient who was admitted to the neurology ward of our hospital due to acute ischemic stroke. The patient was treated with a vitamin K antagonist (warfarin). However, on the third day, his condition deteriorated (his GCS regressed from 11/15 to 5/15). His pupils were anisocoric. Brain CT showed extensive subarachnoid hemorrhage without intraparenchymal involvement. Cerebral magnetic resonance angiography ruled out aneurysmal rupture. The patient was intubated and transferred to the intensive care unit. Due to his poor condition, neurosurgical intervention could not be done. The patient was managed conservatively, but the patient passed away 4 days later in the intensive care unit.

Clinical discussion

Non-traumatic SAH is mostly caused by aneurysmal rupture. Warfarin increases the risk of intracranial hemorrhage and mostly causes intraparenchymal hemorrhage. Isolated warfarin-related SAH without parenchymal involvement is a rare event. Here we present a young male patient with an isolated warfarin-induced SAH.

Conclusion

Warfarin is rarely associated with isolated subarachnoid hemorrhage. This case highlights a young male patient with spontaneous SAH after warfarin therapy for acute ischemic stroke. Aneurysmal rupture and trauma should be excluded before a diagnosis of warfarin-induced SAH is made.

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.

Restarting Oral Anticoagulation in Patients With Atrial Fibrillation After an Intracranial Hemorrhage

Atrial fibrillation is the most common sustained cardiac arrhythmia in the general population. In western countries with aging populations, atrial fibrillation poses a significant health concern, as it is associated with a high risk of thromboembolism, stroke, congestive heart failure, and myocardial infarction. Thrombi are generated in the left atrial appendage, and subsequent embolism into the cerebral circulation is a major cause of ischemic stroke. Therefore, patients have a lifetime risk of stroke, and those at high risk, defined as a CHA2DS2-VASc2 (congestive heart failure, hypertension, age >75 years, diabetes mellitus, stroke/transient ischemic attack/thromboembolism, vascular disease, age 65-74 yrs, sex category) ≥2, are usually placed on oral anticoagulants. Unfortunately, long-term anticoagulation poses bleeding risks, of which intracranial hemorrhage (ICH) is the most feared and deadly complication.In patients who survive an ICH, the question of oral anticoagulation resumption arises. It is a therapeutic dilemma in which clinicians must decide how to manage the risk of thromboembolism versus recurrent hemorrhage. Although there is a substantial amount of retrospective data on the topic of resumption of anticoagulation, there are, at this time, no randomized controlled trials addressing the issue. We therefore sought to address ICH risk and management, summarize high quality existing evidence on restarting oral anticoagulation, and suggest an approach to clinical decision-making.

Cerebral microbleeds in patients with ischemic cerebrovascular disease taking aspirin or clopidogrel

Cerebral microbleeds (CMBs) may be markers of intracerebral bleeding risk in patients receiving antithrombotic drugs. This study aimed to analyze CMBs and white matter hyperintensities (WMHs) in patients taking aspirin or clopidogrel.This retrospective study included patients with ischemic cardiovascular disease administered 75 mg/day aspirin (n = 150) or clopidogrel (n = 150, matched for age and gender) for >1 year (Affiliated Hospital of Inner Mongolia Medical University, China, from July, 2010 to July, 2015). Patients underwent T2-weighted imaging, T1-weighted imaging, diffusion-weighted imaging (DWI) and enhanced T2*-weighted angiography (ESWAN) imaging (3.0-Tesla scanner). Baseline vascular risk factors for CMBs and macroscopic bleeding (MB) were evaluated using univariate and multivariate analyses.The aspirin and clopidogrel groups did not differ significantly in baseline characteristics or prevalences of CMBs or MB. The odds of MB were higher in patients with CMBs than in patients without CMBs in both the aspirin (odds ratio, 95% confidence interval: 4.09, 1.93-8.68; P < .001) and clopidogrel (6.42, 2.83-14.57; P < .001) groups. The odds of WMHs were also higher in patients with CMBs in both the aspirin (3.28, 1.60-6.71; P = .001) and clopidogrel (4.09, 1.91-8.75; P < .001) groups. Patients receiving treatment for >5 years showed elevated risk of CMBs in the aspirin (0.17; 0.09-0.36; P < .001) and clopidogrel (0.15, 0.07-0.33; P < .001) groups as well as higher odds of MB in the aspirin (0.34, 0.16-0.71; P = .004) and clopidogrel (0.37, 0.17-0.80; P = .010) groups.The WMHs and MB were associated with CMBs in patients taking aspirin or clopidogrel for >1 year, and long-term use increased the risks of CMB and bleeding.

Prior Antithrombotic Therapy Is Associated With Cerebral Microbleeds in Ischemic Stroke Patients With Atrial Fibrillation and/or Rheumatic Heart Disease

Background and purpose: Cerebral microbleeds (CMBs) could contribute to an increased risk of intracerebral hemorrhage in patients with antithrombotic therapy (antiplatelets or anticoagulants). Antithrombotic agents are commonly prescribed to the patients with atrial fibrillation (AF) and/or rheumatic heart disease (RHD) for preventing ischemic stroke. However, the impact of antithrombotic therapy on CMBs remained controversial. We aimed to explore the association between the prevalence of CMBs and prior antithrombotic therapy in ischemic stroke patients with AF and/or RHD.

Materials and Methods: Ischemic stroke patients with AF and/or RHD within 7 days of onset from two hospitals were enrolled. Clinical information, prior use of antiplatelets or anticoagulation, presence and location of CMBs on susceptibility weighted imaging were recorded. We investigated the association of antithrombotic use with the presence or location of CMBs using multivariable logistic regression.

Results: A total of 160 patients (68 males; median age, 71 years) were included. CMBs were observed in 90 (56.3%) patients, of whom 37 were with strictly lobar CMBs and 53 were with deep or infratentorial CMBs. There was a significant difference in antiplatelet use between patients with and without CMBs (33.3 vs. 11.4%, P = 0.001), but not found in anticoagulants. Prior use of antiplatelets was independently associated with the presence of CMBs (OR 3.075, 95% CI 1.175–8.045, P = 0.022) and especially strictly lobar CMBs (OR 2.635, 95% CI 1.050–6.612, P = 0.039) in multivariate analysis.

Conclusions: The present study suggests that CMBs are common in ischemic stroke patients with AF and/or RHD and prior antiplatelet use may relate to the presence of CMBs predominantly in the strictly lobar region. Whether anticoagulants could cause CMBs need to be determined in future longitudinal studies.

Prevalence of Cerebral Microbleeds in Patients With Continuous-Flow Left Ventricular Assist Devices

BACKGROUND

The prevalence of cerebral microbleeds (CMBs) in gradient echo T2*-weighted brain MRI has a positive correlation with hemorrhagic stroke incidence. However, the prevalence of CMBs in patients with left ventricular assist devices (LVADs) has not been evaluated. We evaluated the prevalence of CMBs and the relationship with hemorrhagic stroke incidence in patients with LVADs.

METHOD AND RESULTS

We analyzed results from brain MRI in prospective examinations of 35 consecutive patients who had undergone LVAD explantation for heart transplantation or recovery since 2011. The number and distribution of CMBs were counted, then the relationship between baseline characteristics and adverse events during LVAD support were analyzed. The mean age was 37.7±12.4 years and the mean LVAD duration was 2.43±1.08 years. Thirty-four (97%) patients had at least one CMB. Nine (26%) developed hemorrhagic stroke during LVAD support, and patients with hemorrhagic stroke had a significantly greater number of CMBs compared with patients without hemorrhagic stroke (5 [interquartile range (IQR), 4-7] versus 9 [IQR, 5-23]; odds ratio 1.14 [95% Confidence Interval (CI), 1.02-1.32], P=0.05). There was no significant relationship between age, LVAD support duration, or systolic blood pressure during LVAD. However, patients who had at least one episode of bacteremia (9 [IQR, 4-16] versus 5 [IQR, 3-7], P=0.06) and pump pocket infection (14 [IQR, 4-27] versus 5 [IQR, 3-7], P=0.08) showed a trend toward a greater number of CMBs than patients without bacteremia.

CONCLUSIONS

Thirty-four (97%) patients with continuous-flow LVAD had at least one CMB, and the number of CMBs were more prevalent in patients with hemorrhagic stroke and in patients with LVAD-related infection.

Use of coumarin anticoagulants and cerebral microbleeds in the general population

BACKGROUND AND PURPOSE

It remains undetermined whether the use of coumarin anticoagulants associates with cerebral microbleeds in the general population. We investigated whether (1) coumarin use relates to higher prevalence and incidence of microbleeds, (2) microbleeds are more frequent in people with higher maximum international normalized ratios (INRs), and (3) among coumarin users, variability in INR associates with microbleed presence.

METHODS

From the population-based Rotterdam Study, 4945 participants aged ≥45 years were included in the cross-sectional analysis, and 3069 participants had follow-up brain MRI. Information on coumarin use was obtained from automated pharmacy records. Coumarin users were monitored, and INR values were measured in consecutive visits. Presence and location of microbleeds were rated on brain MRI. We investigated the association of coumarin use with microbleeds using multivariable logistic regression.

RESULTS

Overall, 8.6% had used coumarin anticoagulants before the first MRI and 5.9% before follow-up MRI. The prevalence of microbleeds was 19.4%, and the incidence was 6.9% during a mean follow-up of 3.9 years (SD, 0.5). Compared with never users, coumarin users had a higher prevalence of deep or infratentorial microbleeds and a higher incidence of any microbleeds, although statistical significance was not reached in the latter. A higher maximum INR was associated with deep or infratentorial microbleeds. Among coumarin users, a greater variability in INR was associated with a higher prevalence of microbleeds.

CONCLUSIONS

Coumarin use is associated with microbleeds. Associations were strongest for people with greater variability in INR.

Intracranial Hemorrhage Among Patients With Atrial Fibrillation Anticoagulated With Warfarin or Rivaroxaban

Background and Purpose—

Intracranial hemorrhage (ICH) is a life-threatening complication of anticoagulation.

Methods—

We investigated the rate, outcomes, and predictors of ICH in 14 264 patients with atrial fibrillation from Rivaroxaban Once Daily, Oral, Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF). Cox proportional hazards modeling was used.

Results—

During 1.94 years (median) of follow-up, 172 patients (1.2%) experienced 175 ICH events at a rate of 0.67% per year. The significant, independent predictors of ICH were race (Asian: hazard ratio, 2.02; 95% CI, 1.39–2.94; black: hazard ratio, 3.25; 95% CI, 1.43–7.41), age (1.35; 1.13–1.63 per 10-year increase), reduced serum albumin (1.39; 1.12–1.73 per 0.5 g/dL decrease), reduced platelet count below 210×10 9 /L (1.08; 1.02–1.13 per 10×10 9 /L decrease), previous stroke or transient ischemic attack (1.42; 1.02–1.96), and increased diastolic blood pressure (1.17; 1.01–1.36 per 10 mm Hg increase). Predictors of a reduced risk of ICH were randomization to rivaroxaban (0.60; 0.44–0.82) and history of congestive heart failure (0.65; 0.47–0.89). The ability of the model to discriminate individuals with and without ICH was good ( C -index, 0.69; 95% CI, 0.64–0.73).

Conclusions—

Among patients with atrial fibrillation treated with anticoagulation, the risk of ICH was higher among Asians, blacks, the elderly, and in those with previous stroke or transient ischemic attack, increased diastolic blood pressure, and reduced platelet count or serum albumin at baseline. The risk of ICH was significantly lower in patients with heart failure and in those who were randomized to rivaroxaban instead of warfarin. The external validity of these findings requires testing in other atrial fibrillation populations.

Antithrombotic therapy for stroke prevention in non-valvular atrial fibrillation

The world faces an epidemic of atrial fibrillation and atrial fibrillation-related stroke. An individual's risk of atrial fibrillation-related stroke can be estimated with the CHADS(2) or CHA(2)DS(2)VASc scores, and reduced by two-thirds with effective anticoagulation. Vitamin K antagonists, such as warfarin, are underused and often poorly managed. The direct thrombin inhibitor dabigatran etexilate and factor Xa inhibitors rivaroxaban and apixaban are new oral anticoagulants that are at least as efficacious and safe as warfarin. Their advantages are predictable anticoagulant effects, low propensity for drug interactions, and lower rates of intracranial haemorrhage than with warfarin. A disadvantage is the continuing need to develop and validate rapidly effective antidotes for major bleeding and standardised tests that accurately measure plasma concentrations and anticoagulant effects, together with the disadvantage of possible higher rates of gastrointestinal haemorrhage and greater expense than with warfarin. The new oral anticoagulants should increase the number of patients with atrial fibrillation at risk of stroke who are optimally anticoagulated, and reduce the burden of atrial fibrillation-related stroke.

Cerebral microbleeds: a new dilemma in stroke medicine

Cerebral microbleeds (CMBs) are an increasingly common neuroimaging finding in the context of ageing, cerebrovascular disease and dementia, with potentially important clinical relevance. Perhaps the most pressing clinical question is whether CMBs are associated with a clinically important increase in the risk of intracerebral haemorrhage (ICH), the most feared complication in patients treated with thrombolytic or antithrombotic (antiplatelet and anticoagulant) drugs. This review will summarize the evidence available regarding CMBs as an indicator of future ICH risk in stroke medicine clinical practice.

Acute subdural hematoma following halo pin tightening in a patient with bilateral vertebral artery dissection

We report the first case of acute subdural hematoma (SDH) developing after tightening the halo of an osteoporotic 61-year-old woman on warfarin therapy for bilateral traumatic vertebral artery dissection. We discuss literature relevant to this case with an emphasis on identifying warning signs, including recurrent pin loosening, especially in patients with compromised bone structure and high risk of bleeding. Our 61-year-old patient presented to neurosurgery clinic for a 2-month follow-up of a type-III odontoid fracture sustained in a motor vehicle accident. The patient had repeatedly loosened halo pins, and shortly after the pins were tightened, the patient had a syncopal event and struck her head. An emergent computed tomography scan revealed acute SDH requiring emergent craniotomy and evacuation. SDH following pin penetration in a patient with bilateral vertebral artery dissection, osteoporosis, and anticoagulation has not been reported as a complication of the use of the halo vest for stabilization of the cervical spine. The risk of this serious complication can be minimized by giving special consideration to patients with comorbidities and by repositioning problematic pins. This case demonstrates the importance of special attention to bone strength, bleeding risk, and recurrent minor complaints with use of the halo vest.

Cerebral microbleeds on magnetic resonance imaging and anticoagulant-associated intracerebral hemorrhage risk

The increasing use of antithrombotic drugs in an aging population [including anticoagulants to prevent future ischemic stroke in individuals with atrial fibrillation (AF)] has been associated with a dramatic increase in the incidence of intracerebral hemorrhage (ICH) in users of antithrombotic drugs. Several lines of evidence suggest that cerebral small vessel disease (particularly sporadic cerebral amyloid angiopathy) is a risk factor for this rare but devastating complication of these commonly used treatments. Cerebral microbleeds (CMBs) have emerged as a key MRI marker of small vessel disease and a potentially powerful marker of future ICH risk, but adequately powered, high quality prospective studies of CMBs and ICH risk on anticoagulation are not available. Further data are urgently needed to determine how neuroimaging and other biomarkers may contribute to individualized risk prediction to make anticoagulation as safe and effective as possible. In this review we discuss the available evidence on cerebral small vessel disease and CMBs in the context of antithrombotic treatments, especially regarding their role as a predictor of future ICH risk after ischemic stroke, where risk-benefit judgments can be a major challenge for physicians. We will focus on patients with AF because these are frequently treated with anticoagulation. We briefly describe the rationale and design of a new prospective observational inception cohort study (Clinical Relevance of Microbleeds in Stroke; CROMIS-2) which investigates the value of MRI markers of small vessel disease (including CMBs) and genetic factors in assessing the risk of oral anticoagulation-associated ICH.

No significant association of aspirin use with cerebral microbleeds in the asymptomatic elderly

BACKGROUND AND PURPOSE

Cerebral microbleeds (CMBs) may predict future risk for intracerebral hemorrhage (ICH). ICH is one of the most important complications of aspirin use. The association between aspirin use and CMBs is still controversial. In this context, we sought to investigate whether aspirin use is associated with CMBs in subjects without previous history of stroke.

METHODS

Asymptomatic elderly subjects (n=1452; age ≥ 65 years) who visited for routine health check-ups were included in this study. CMBs were evaluated through T2*-weighted gradient-recalled echo MRI. Information about aspirin or warfarin use was obtained using a structured questionnaire.

RESULTS

A total of 138 subjects (9.5%) were found to have CMBs. In the group of aspirin use, 43 subjects (11.2%) had CMBs; among them 9 (2.3%) had strictly lobar microbleeds and 34 (8.9%) had deep or infratentorial microbleeds. Compared with the non-use group, the risk for CMBs did not increase in the group of aspirin use (adjusted odds ratio, 1.10; 95% confidence interval, 0.73-1.66). For the group of aspirin use above 5 years, the proportion of CMBs (11.1%) did not increase compared with the group of short-term use (≤ 5 years, 9.5%, p=0.99) and non-use group (8.9%, p=0.66).

CONCLUSIONS

We found that the prevalence of CMBs did not increase in the group of aspirin use, and the presence of CMBs was not associated with the duration of aspirin use in asymptomatic elderly subjects without a history of stroke or transient ischemic attack.

Mixed cerebrovascular disease and the future of stroke prevention

Stroke prevention efforts typically focus on either ischemic or hemorrhagic stroke. This approach is overly simplistic due to the frequent coexistence of ischemic and hemorrhagic cerebrovascular disease. This coexistence, termed “mixed cerebrovascular disease”, offers a conceptual framework that appears useful for stroke prevention strategies. Mixed cerebrovascular disease incorporates clinical and subclinical syndromes, including ischemic stroke, subclinical infarct, white matter disease of aging (leukoaraiosis), intracerebral hemorrhage, and cerebral microbleeds. Reliance on mixed cerebrovascular disease as a diagnostic entity may assist in stratifying risk of hemorrhagic stroke associated with platelet therapy and anticoagulants. Animal models of hemorrhagic cerebrovascular disease, particularly models of cerebral amyloid angiopathy and hypertension, offer novel means for identifying underlying mechanisms and developing focused therapy. Phosphodiesterase (PDE) inhibitors represent a class of agents that, by targeting both platelets and vessel wall, provide the kind of dual actions necessary for stroke prevention, given the spectrum of disorders that characterizes mixed cerebrovascular disease.

Aspirin treatment increases the risk of cerebral microbleeds

BACKGROUND

The objective of the study was to determine the frequency of cerebral microbleeds (CMBs) by using phasesensitive imaging in patients with previous transient ischemic attack (TIA) or stroke who were receiving aspirin treatment.

METHODS

We retrospectively analyzed 300 outpatients with ischemic cerebrovascular disease: 150 had been receiving aspirin treatment for >1 year (patients), and 150 controls had not previously received aspirin. Cerebral microbleeds were defined by a trained observer (blinded to clinical details) according to results of T2-weighted, T1-weighted, diffusion-weighted, and phase-sensitive magnetic resonance imaging (MRI). Numerous vascular risk factors including white matter hyperintensity (WMH), duration of aspirin treatment, age, hypertension or diabetes mellitus were investigated for a possible association with the presence of CMBs in the two groups.

RESULTS

The frequency of CMBs (60/150 (40%) vs 18/150 (12%); odds ratio 4.899, p <0.0001) and intracerebral hemorrhage (ICH)(42/150 (28%) vs 2/150 (1%); odds ratio 28.778, p <0.0001) were significantly higher in the patients than in the controls. Among patients, those using aspirin for >5 years(42/68 (62%) showed a higher frequency of CMBs than those receiving aspirin for ≤ 5 years(18/82 (22%); odds ratio 5.744, p<0.0001). WMH (p=0.020/0.030, 0.007/0.000) age (p=0.007/0.000) and hypertension (p=0.000/0.033), in patients and controls respectively, were each associated with CMBs.

CONCLUSIONS

There was a clear impact of aspirin treatment on CMBs associated with intracerebral hemorrhage in Chinese patients. The frequency of CMBs and hemorrhagic complications was higher in patients treated with long-term aspirin.

Cerebral microbleeds: detection, mechanisms and clinical challenges

In the last decade or so, cerebral microbleeds (CMBs) – tiny perivascular hemorrhages seen as small, well-demarcated, hypointense, rounded lesions on MRI sequences that are sensitive to magnetic susceptibility – have generated increasing interest among neurologists and clinical stroke researchers. As MRI techniques become more sophisticated, CMBs are increasingly detected in various patient populations (including all types of stroke, Alzheimer’s disease and vascular cognitive impairment) and healthy community-dwelling older people. Their presence raises many clinical dilemmas and intriguing pathophysiological questions. CMBs are emerging as an important new manifestation and diagnostic marker of cerebral small-vessel disease. They are a potential predictor of future intracerebral hemorrhage risk, a possible contributor to cognitive impairment and dementia and a potential key link between vascular and degenerative pathologies. In this article, we discuss the available pathological, neuroimaging and clinical studies in the field, and we provide a modern overview of the clinical and pathophysiological implications of CMBs in different disease settings.

Antithrombotic drug use, cerebral microbleeds, and intracerebral hemorrhage: a systematic review of published and unpublished studies

BACKGROUND AND PURPOSE

Cerebral microbleeds (MB) are potential risk factors for intracerebral hemorrhage (ICH), but it is unclear if they are a contraindication to using antithrombotic drugs. Insights could be gained by pooling data on MB frequency stratified by antithrombotic use in cohorts with ICH and ischemic stroke (IS)/transient ischemic attack (TIA).

METHODS

We performed a systematic review of published and unpublished data from cohorts with stroke or TIA to compare the presence of MB in: (1) antithrombotic users vs nonantithrombotic users with ICH; (2) antithrombotic users vs nonusers with IS/TIA; and (3) ICH vs ischemic events stratified by antithrombotic use. We also analyzed published and unpublished follow-up data to determine the risk of ICH in antithrombotic users with MB.

RESULTS

In a pooled analysis of 1460 ICH and 3817 IS/TIA, MB were more frequent in ICH vs IS/TIA in all treatment groups, but the excess increased from 2.8 (odds ratio; range, 2.3-3.5) in nonantithrombotic users to 5.7 (range, 3.4-9.7) in antiplatelet users and 8.0 (range, 3.5-17.8) in warfarin users (P difference=0.01). There was also an excess of MB in warfarin users vs nonusers with ICH (OR, 2.7; 95% CI, 1.6-4.4; P<0.001) but none in warfarin users with IS/TIA (OR, 1.3; 95% CI, 0.9-1.7; P=0.33; P difference=0.01). There was a smaller excess of MB in antiplatelet users vs nonusers with ICH (OR, 1.7; 95% CI, 1.3-2.3; P<0.001), but findings were similar for antiplatelet users with IS/TIA (OR, 1.4; 95% CI, 1.2-1.7; P<0.001; P difference=0.25). In pooled follow-up data for 768 antithrombotic users, presence of MB at baseline was associated with a substantially increased risk of subsequent ICH (OR, 12.1; 95% CI, 3.4-42.5; P<0.001).

CONCLUSIONS

The excess of MB in warfarin users with ICH compared to other groups suggests that MB increase the risk of warfarin-associated ICH. Limited prospective data corroborate these findings, but larger prospective studies are urgently required.