Cerebral Microbleeds and the Effect of Intensive Blood Pressure Reduction on Hematoma Expansion and Functional Outcomes: A Secondary Analysis of the ATACH-2 Randomized Clinical Trial

Exploring the Impact of Cerebral Microbleeds on Stroke Management

Stroke constitutes a major cause of functional disability and mortality, with increasing prevalence. Thus, the timely and accurate prognosis of stroke outcomes based on clinical or radiological markers is vital for both physicians and stroke survivors. Among radiological markers, cerebral microbleeds (CMBs) constitute markers of blood leakage from pathologically fragile small vessels. In the present review, we evaluated whether CMBs affect ischemic and hemorrhagic stroke outcomes and explored the fundamental question of whether CMBs may shift the risk-benefit balance away from reperfusion therapy or antithrombotic use in acute ischemic stroke patients. A literature review of two databases (MEDLINE and Scopus) was conducted to identify all the relevant studies published between 1 January 2012 and 9 November 2022. Only full-text articles published in the English language were included. Forty-one articles were traced and included in the present review. Our findings highlight the utility of CMB assessments, not only in the prognostication of hemorrhagic complications of reperfusion therapy, but also in forecasting hemorrhagic and ischemic stroke patients' functional outcomes, thus indicating that a biomarker-based approach may aid in the provision of counseling for patients and families, improve the selection of more appropriate medical therapies, and contribute to a more accurate choice of patients for reperfusion therapy.

Radiomics for prediction of intracerebral hemorrhage outcomes: A retrospective multicenter study

BACKGROUND

Accurate risk stratification of patients with intracerebral hemorrhage (ICH) could help refine adjuvant therapy selection and better understand the clinical course. We aimed to evaluate the value of radiomics features from hematomal and perihematomal edema areas for prognosis prediction and to develop a model combining clinical and radiomic features for accurate outcome prediction of patients with ICH.

METHODS

This multicenter study enrolled patients with ICH from January 2016 to November 2021. Their outcomes at 3 months were recorded based on the modified Rankin Scale (good, 0-3; poor, 4-6). Independent clinical and radiomic risk factors for poor outcome were identified through multivariate logistic regression analysis, and predictive models were developed. Model performance and clinical utility were evaluated in both internal and external cohorts.

RESULTS

Among the 1098 ICH patients evaluated (mean age, 60 ± 13 years), 703 (64 %) had poor outcomes. Age, hemorrhage volume and location, and Glasgow Coma Scale (GCS) were independently associated with outcomes. The area under the receiver operating characteristic curve (AUC) of the clinical model was 0.881 in the external validation cohort. Addition of the Rad-score (combined hematoma and perihematomal edema area) improved predictive accuracy and model performance (AUC, 0.893), net reclassification improvement, 0.140 (P < 0.001), and integrated discrimination improvement, 0.050 (P < 0.001).

CONCLUSIONS

The radiomics features of hematomal and perihematomal edema area have additional value in prognostic prediction; moreover, addition of radiomic features significantly improves model accuracy.

Development and Validation of a Clinical-Based Signature to Predict the 90-Day Functional Outcome for Spontaneous Intracerebral Hemorrhage

We aimed to develop and validate an objective and easy-to-use model for identifying patients with spontaneous intracerebral hemorrhage (ICH) who have a poor 90-day prognosis. This three-center retrospective study included a large cohort of 1,122 patients with ICH who presented within 6 h of symptom onset [training cohort, n = 835; internal validation cohort, n = 201; external validation cohort (center 2 and 3), n = 86]. We collected the patients’ baseline clinical, radiological, and laboratory data as well as the 90-day functional outcomes. Independent risk factors for prognosis were identified through univariate analysis and multivariate logistic regression analysis. A nomogram was developed to visualize the model results while a calibration curve was used to verify whether the predictive performance was satisfactorily consistent with the ideal curve. Finally, we used decision curves to assess the clinical utility of the model. At 90 days, 714 (63.6%) patients had a poor prognosis. Factors associated with prognosis included age, midline shift, intraventricular hemorrhage (IVH), subarachnoid hemorrhage (SAH), hypodensities, ICH volume, perihematomal edema (PHE) volume, temperature, systolic blood pressure, Glasgow Coma Scale (GCS) score, white blood cell (WBC), neutrophil, and neutrophil-lymphocyte ratio (NLR) (p < 0.05). Moreover, age, ICH volume, and GCS were identified as independent risk factors for prognosis. For identifying patients with poor prognosis, the model showed an area under the receiver operating characteristic curve of 0.874, 0.822, and 0.868 in the training cohort, internal validation, and external validation cohorts, respectively. The calibration curve revealed that the nomogram showed satisfactory calibration in the training and validation cohorts. Decision curve analysis showed the clinical utility of the nomogram. Taken together, the nomogram developed in this study could facilitate the individualized outcome prediction in patients with ICH.

Blood Pressure Management After Intracerebral and Subarachnoid Hemorrhage: The Knowns and Known Unknowns

Blood pressure (BP) elevations often complicate the management of intracerebral hemorrhage and aneurysmal subarachnoid hemorrhage, the most serious forms of acute stroke. Despite consensus on potential benefits of BP lowering in the acute phase of intracerebral hemorrhage, controversies persist over the timing, mechanisms, and approaches to treatment. BP control is even more complex for subarachnoid hemorrhage, where there are rationales for both BP lowering and elevation in reducing the risks of rebleeding and delayed cerebral ischemia, respectively. Efforts to disentangle the evidence has involved detailed exploration of individual patient data from clinical trials through meta-analysis to determine strength and direction of BP change in relation to key outcomes in intracerebral hemorrhage, and which likely also apply to subarachnoid hemorrhage. A wealth of hemodynamic data provides insights into pathophysiological interrelationships of BP and cerebral blood flow. This focused update provides an overview of current evidence, knowledge gaps, and emerging concepts on systemic hemodynamics, cerebral autoregulation and perfusion, to facilitate clinical practice recommendations and future research.

Cerebral Microbleeds and Acute Hematoma Characteristics in the ATACH-2 and MISTIE III Trials

BACKGROUND AND OBJECTIVES

To study the relationship between the presence of cerebral microbleeds (CMBs) and acute hematoma characteristics among patients with primary intracerebral hemorrhage (ICH).

METHODS

We pooled individual patient data from the Antihypertensive Treatment of Acute Cerebral Hemorrhage 2 (ATACH-2) trial and the Minimally Invasive Surgery Plus Alteplase for Intracerebral Hemorrhage Evacuation phase 3 (MISTIE III) trial. We included individuals with a brain MRI scan. Exposure was the presence of a CMB. The coprimary outcomes were admission ICH volume and hematoma expansion. Mixed-effects linear and logistic regression models were used, with demographics and comorbid conditions considered fixed effects and the study cohort treated as a random effect. Additional analyses assessed the relationship between CMB topography and number and hematoma characteristics.

RESULTS

Of the 1,499 patients with ICH enrolled in the parent trials, 466 (31.1%) were included in this analysis, and 231 (49.6%) patients had CMBs. In adjusted models, presence of CMBs was associated with smaller ICH volume (β = -0.26, 95% confidence interval [CI] -0.44 to -0.08) and lower odds of hematoma expansion (odds ratio 0.65, 95% CI 0.40-0.95; p = 0.04). The strength of association between CMBs and hematoma characteristics increased with increasing number of CMBs. The location of the CMBs and the severity of leukoaraiosis did not modify these results.

DISCUSSION

In a pooled cohort of patients with ICH, our results are consistent with the hypothesis that more severe underlying small vessel disease, as represented by CMBs, leads to smaller baseline hematoma volumes and reduced hematoma expansion. Underlying cerebral small vessel disease may be of prognostic significance after ICH.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT01176565 and NCT01827046.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that the presence of microbleeds on MRI is associated with a smaller ICH volume at presentation and a lower rate of hematoma expansion on follow-up imaging.

Intensive Blood Pressure Lowering and DWI Lesions in Intracerebral Hemorrhage: Exploratory Analysis of the ATACH-2 Randomized Trial

BACKGROUND

With the increasing use of magnetic resonance imaging in the assessment of acute intracerebral hemorrhage, diffusion-weighted imaging hyperintense lesions have been recognized to occur at sites remote to the hematoma in up to 40% of patients. We investigated whether blood pressure reduction was associated with diffusion-weighted imaging hyperintense lesions in acute intracerebral hemorrhage and whether such lesions are associated with worse clinical outcomes by analyzing imaging data from a randomized trial.

METHODS

We performed exploratory subgroup analyses in an open-label randomized trial that investigated acute blood pressure lowering in 1000 patients with intracerebral hemorrhage between May 2011 and September 2015. Eligible participants were assigned to an intensive systolic blood pressure target of 110-139 mm Hg versus 140-179 mm Hg with the use of intravenous nicardipine. Of these, 171 patients had requisite magnetic resonance imaging sequences for inclusion in these subgroup analyses. The primary outcome was the presence of diffusion-weighted imaging hyperintense lesions. Secondary outcomes included death or disability and serious adverse event at 90 days.

RESULTS

Diffusion-weighted imaging hyperintense lesions were present in 25% of patients (mean age 62 years). Hematoma volume > 30 cm³ was an adjusted predictor (adjusted relative risk 2.41, 95% confidence interval 1.00-5.80) of lesion presence. Lesions occurred in 25% of intensively treated patients and 24% of standard treatment patients (relative risk 1.01, 95% confidence interval 0.71-1.43, p = 0.97). Patients with diffusion-weighted imaging hyperintense lesions had similar frequencies of death or disability at 90 days, compared with patients without lesions.

CONCLUSIONS

Randomized assignment to intensive acute blood pressure lowering did not result in a greater frequency of diffusion-weighted imaging hyperintense lesion. Alternative mechanisms of diffusion-weighted imaging hyperintense lesion formation other than hemodynamic fluctuations need to be explored. Clinical trial registration ClinicalTrials.gov (Ref. NCT01176565; https://clinicaltrials.gov/ct2/show/NCT01176565 ).

Microbleeds and the Effect of Anticoagulation in Patients With Embolic Stroke of Undetermined Source: An Exploratory Analysis of the NAVIGATE ESUS Randomized Clinical Trial

Importance

The reported associations of cerebral microbleeds with recurrent stroke and intracerebral hemorrhage have raised concerns regarding antithrombotic treatment in patients with a history of stroke and microbleeds on magnetic resonance imaging.

Objective

To characterize microbleeds in embolic strokes of undetermined source (ESUS) and report interactions between microbleeds and the effects of random assignment to anticoagulant vs antiplatelet therapy.

Design, Setting, and Participants

Subgroup analyses of the New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial vs Aspirin to Prevent Embolism in ESUS (NAVIGATE ESUS) international, double-blind, randomized, event-driven phase 3 clinical trial. Participants were enrolled between December 2014 and September 2017 and followed up for a median of 11 months. The study setting included 459 stroke recruitment centers in 31 countries. Patients aged 50 years or older who had neuroimaging-confirmed ESUS between 7 days and 6 months before screening were eligible. Of these 7213 NAVIGATE ESUS participants, 3699 (51%) had information on cerebral microbleeds reported on their baseline clinical magnetic resonance imaging and were eligible for these analyses. Patients with a prior history of symptomatic intracerebral hemorrhage were excluded from the NAVIGATE ESUS trial.

Interventions

Rivaroxaban, 15 mg, compared with aspirin, 100 mg, daily.

Main Outcomes and Measures

The primary outcome was recurrent stroke. Secondary outcomes were ischemic stroke, intracerebral hemorrhage, and all-cause mortality.

Results

Microbleeds were present in 395 of 3699 participants (11%). Of patients with cerebral microbleeds, mean (SD) age was 69.5 (9.4) years, 241 were men (61%), and 201 were White (51%). Advancing age (odds ratio [OR] per year, 1.03; 95% CI, 1.01-1.04), East Asian race/ethnicity (OR, 1.57; 95% CI, 1.04-2.37), hypertension (OR, 2.20; 95% CI, 1.54-3.15), multiterritorial infarcts (OR, 1.95; 95% CI, 1.42-2.67), chronic infarcts (OR, 1.78; 95% CI, 1.42-2.23), and occult intracerebral hemorrhage (OR, 5.23; 95% CI, 2.76-9.90) were independently associated with microbleeds. The presence of microbleeds was associated with a 1.5-fold increased risk of recurrent stroke (hazard ratio [HR], 1.5; 95% CI, 1.0-2.3), a 4-fold risk of intracerebral hemorrhage (HR, 4.2; 95% CI, 1.3-13.9), a 2-fold risk of all-cause mortality (HR, 2.1; 95% CI, 1.1-4.3), and strictly lobar microbleeds with an approximately 2.5-fold risk of ischemic stroke (HR, 2.3; 95% CI, 1.3-4.3). There were no interactions between microbleeds and treatment assignments for recurrent stroke, ischemic stroke, or all-cause mortality. The HR of intracerebral hemorrhage on rivaroxaban was similar between persons with microbleeds (HR, 3.1; 95% CI, 0.3-30.0) and persons without microbleeds (HR, 3.0; 95% CI, 0.6-14.7; interaction P = .97).

Conclusions and Relevance

Microbleeds mark an increased risk of recurrent stroke, ischemic stroke, intracerebral hemorrhage, and mortality in ESUS but do not appear to influence effects of rivaroxaban on clinical outcomes.

Trial Registration

ClinicalTrials.gov Identifier: NCT02313909.

Vascular Risk Factors, Imaging, and Outcomes in Transient Ischemic Attack/Ischemic Stroke Patients with Neuroimaging Evidence of Probable/Possible Cerebral Amyloid Angiopathy

Background

In TIA/ischemic stroke patients, the clinical significance of lobar microbleeds potentially indicating cerebral amyloid angiopathy (CAA) is unknown. We assessed vascular risk factors and outcomes, including cognition, in TIA/ischemic stroke patients with neuroimaging evidence of probable/possible CAA.

Methods

This prospective cohort was conducted from August 2015 and January 2018 at 40 centers. 2625 participants were collected. Eligible participants were aged at least 55 years. Montreal Cognitive Assessment (MoCA) score is less than or equal to 26. A total of 1620 patients were included. 1604 (99.0%) and 1582 (97.7%) participants are followed up at 3 and 12 months. The primary outcomes were death or disability (mRS score, 3-6) and Montreal Cognitive Assessment (MoCA) at 3 months and 12 months. Demographic and vascular risk factors were measured at baseline (smoking, alcohol, diabetes, atrial fibrillation, hypertension, hypercholesterolemia, coronary artery disease, ischemic stroke, and transient ischemic attack). Blood samples were collected within 24 hours of admission. MRI was recommended for all patients. MoCA score was evaluated at baseline and follow-up.

Results

In total, 291/1620 patients with ischemic stroke/TIA (32.7% female and mean age, 67.8 years) had neuroimaging evidence of probable/possible CAA. Higher age, history of hypertension, atrial fibrillation, ischemic stroke, alcohol, and high glucose at the admission were more common in the patients. Mean MoCA changed from 21.4 at 3 months (SD 5.2) to 22.3 at 12 months (SD 4.7), difference 0.3 (SD 3.8). At the 3-month and 12-month follow-up, there were significant differences in age, education level, and sex among different cognitive groups. Higher age, lower education (less than high school), and female sex were the predictors of changing in MoCA score from 3 months to 12 months. Moreover, age (more than 66 years) and education (less than high school) are strongly associated with MoCA at 3- and 12-month follow-up. 30 of 286 (10.5%) and 37 of 281 (13.2%) patients had poor outcome of death or disability (modified Rankin Scale score, 3-6) at follow-up 3 and 12 months. Cortical superficial siderosis (cSS) was associated with higher mRS at follow-up. cSS status, cSS count 1-2, cSS strictly lobar, and strictly deep might be the risks of outcomes in adjusted analyses.

Conclusion

This study suggested that an increasing number of vascular risk factors and imaging markers were significantly associated with outcomes of TIA/ischemic stroke patients with CAA pattern. Male, young patients with high education should get better cognitive recovery.

Neuroimaging of Acute Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) accounts for 10% to 20% of all strokes worldwide and is associated with high morbidity and mortality. Neuroimaging is clinically important for the rapid diagnosis of ICH and underlying etiologies, but also for identification of ICH expansion, often as-sociated with an increased risk for poor outcome. In this context, rapid assessment of early hema-toma expansion risk is both an opportunity for therapeutic intervention and a potential hazard for hematoma evacuation surgery. In this review, we provide an overview of the current literature surrounding the use of multimodal neuroimaging of ICH for etiological diagnosis, prediction of early hematoma expansion, and prognostication of neurological outcome. Specifically, we discuss standard imaging using computed tomography, the value of different vascular imaging modalities to identify underlying causes and present recent advances in magnetic resonance imaging and computed tomography perfusion.

Plasma D-dimer predicts poor outcome and mortality after spontaneous intracerebral hemorrhage

BACKGROUND

The elevation of plasma D-dimer levels may predict a higher risk of thrombosis and play a role in the pathological process of patients after spontaneous intracerebral hemorrhage (ICH). However, its function in predicting the prognosis of ICH has not been verified on large cases.

PATIENTS AND METHODS

Retrospective cohort study of 1,332 consecutive patients with spontaneous ICH at an academic medical center was conducted. Functional outcome at three months after ICH was dichotomized using the modified Rankin Scale (0-2 versus 3-6). D-dimer level in blood was analyzed within 1 hr of admission. An ICH outcome score combining D-dimer level for evaluating poor functional outcome and mortality was tested.

RESULTS

The proportion of patients with poor functional outcome and mortality at three months was significantly higher in patients with elevated D-dimer level (p < .001). Multivariable analysis demonstrated that elevated D-dimer level was an independent predictor of poor functional outcome (odds ratio 1.486, 95% confidence interval 1.086-2.060, p = .014) and mortality (odds ratio 2.015, 95% confidence interval 1.186-3.423, p = .01). An increasing ICH outcome score combining D-dimer level was associated with increased poor functional outcome and mortality.

CONCLUSIONS

Elevated plasma D-dimer level after spontaneous ICH is associated with poor functional outcome and mortality. The study suggests that elevated D-dimer level has a predictive value for outcome and mortality in patients with spontaneous ICH.

White Matter Hyperintensities and Blood Pressure Lowering in Acute Intracerebral Hemorrhage: A Secondary Analysis of the ATACH-2 Trial

BACKGROUND

It is not clear whether subsets of patients with intracerebral hemorrhage (ICH) benefit from intensive blood pressure (BP) lowering. We evaluated whether white matter hyperintensities (WMH) burden influences response to this therapy.

METHODS

Retrospective secondary analysis of the Antihypertensive Treatment of Acute Cerebral Hemorrhage 2 trial. Patients were randomized to intensive (systolic BP target: 110-139 mmHg) versus standard (systolic BP target: 140-179 mmHg) BP treatment with intravenous nicardipine within 4.5 h from onset between May 2011 and September 2015. WMH were rated on magnetic resonance images (fluid-attenuated inversion recovery sequences), defining moderate-severe WMH as total Fazekas scale score ≥ 3 (range 0-6). The main outcome was death or major disability at 90 days (modified Rankin scale ≥ 3). The secondary outcome was ICH expansion, defined as hematoma growth > 33% from baseline to follow-up CT scan. Predictors of the outcomes of interest were explored with multivariable logistic regression.

RESULTS

A total of 195/1000 patients had MRI images available for analysis, of whom 161 (82.6%) had moderate-severe WMH. When compared to patients with none-mild WMH, those with moderate-severe WMH did not have an increased risk of death or major disability (adjusted relative risk: 1.83, 95% CI 0.71-4.69) or ICH expansion (adjusted relative risk: 1.14, 95% CI 0.38-3.37). WMH burden did not modify the effect of intensive BP treatment on outcome (all p for interaction ≥ 0.2).

CONCLUSION

The majority of acute ICH patients have moderate-severe WMH, but advanced small vessel disease burden marked by WMH does not influence ICH-related outcomes or response to intensive BP reduction.

Role of Cerebral Microbleeds for Intracerebral Haemorrhage and Dementia

PURPOSE OF REVIEW

Cerebral microbleeds (CMB)-small round or ovoid lesions detected in hyposignal on blood-sensitive MRI sequences-are promising radiological biomarkers of cerebral small vessel disease. Their relations with ischaemic or haemorragic stroke and their potential contribution to dementia have been extensively addressed. This article reviews recent research on the clinical significance of CMB that remains to be determined.

RECENT FINDINGS

The presence, burden and location of CMB allow to obtain a more accurate estimate of intracerebral haemorrhage and ischaemic stroke risk. Most studies evaluating the association between CMB and dementia are hampered by methodological limitations and show conflicting results. CMB mainly reflect the severity of the underlying small vessel disease and should not be interpreted independently of the others neuroimaging biomarkers or the clinical setting. Future large prospective longitudinal studies and randomized controlled trials in various settings are required to determine whether specific therapies are beneficial in case of incidental findings.

[Atypical intracerebral hemorrhage-etiology and acute management]

Acute management as well as establishing the etiology of an intracerebral hemorrhage is still a challenge for clinicians. The location of the intracerebral hemorrhage alone should not be used to determine the cause because atypically located hemorrhages can be caused by long-standing arterial hypertension and typically located hemorrhages can occur due to non-hypertensive causes. Besides discussing the classification of intracerebral hemorrhages, this article focuses on a diagnostic algorithm as well as the presentation of potential (rarer) causes of non-traumatic intracerebral hemorrhages. Furthermore, the acute treatment of intracerebral hemorrhage with respect to recent data on blood pressure management as well as the management of bleeding under oral anticoagulant treatment are described.

A Follow-up Study of Cerebral Microbleeds in Patients Who Received Stents for Symptomatic Cerebral Artery Stenosis

BACKGROUND

The aims of this study were to explore (i) the dynamic changes in cerebral microbleeds (CMBs) in patients with symptomatic cerebral artery stenosis who received endovascular stent-assisted angioplasty and (ii) the risk factors associated with the new incidence of CMBs as well as whether CMBs increased the risk of vascular events in these patients.

METHODS

Clinical information and magnetic resonance images were collected on admission and 3 months after endovascular stent-assisted angioplasty. Based on susceptibility-weighted imaging, the patients were divided into groups with or without newly developed CMBs, and between-group differences in risk factors were compared. We also compared whether CMBs increased the risk of vascular events among those patients.

RESULTS

Seventy-three patients completed the relevant follow-up examinations. After an average follow-up period of 109 days, 7 (9.6%) patients showed new CMBs. A univariate analysis showed that the number of lacunar infarcts and the increase in systolic blood pressure were higher in patients with new CMBs than in those without new CMBs, and these differences were significant (P = 0.034, P = 0.001). Increased systolic blood pressure was an independent risk factor for developing new CMBs (P = 0.017).

CONCLUSIONS

CMBs may be a continuously progressing cerebral small-vessel disease. The newly developed CMBs in patients with intracranial and/or extracranial stents were associated with increased systolic blood pressure but not with the number of baseline CMBs.