New microbleeds after thrombolysis: contiguous thin-slice 3T MRI

Prevalence, Risk Factors, and Clinical Outcomes of New Cerebral Microbleeds After Intravenous Thrombolysis in Acute Ischemic Stroke: a Systematic Review and Meta-analysis

BACKGROUND

Cerebral microbleeds (CMBs) are common in the elderly population, and are associated with an increased risk of stroke and dementia. An acute ischemic stroke event can make CMBs develop rapidly. However, the progression of CMBs after intravenous thrombolysis is not well understood.

METHODS

Following a previously registered protocol, PubMed, Web of Science, and Embase databases were systematically searched to identify relevant literature up to August 2022. Cohort studies that reported new CMBs in patients with acute ischemic stroke undergoing intravenous thrombolysis were included. Random effects models were used to calculate the pooled estimates.

RESULTS

Seven studies with 1079 patients were included in the meta-analysis. The pooled new CMBs prevalence was 7.6% (95% CI 3.9-14.3%) and 63.6% new CMBs were located in the cerebral lobes. Compared with patients without new CMBs, those with new CMBs were older, had a higher proportion of hypertension, and had higher systolic blood pressure and baseline CMBs burden. The presence of new CMBs increased the likelihood of remote intracerebral hemorrhage (OR 28.75, 95% CI 8.58-96.38) and symptomatic intracerebral hemorrhage (OR 15.49, 95% CI 3.21-74.73) but was not related to functional outcomes or hemorrhagic transformation.

CONCLUSIONS

The prevalence of new CMBs after intravenous thrombolysis was approximately 7.6%. The presence of new CMBs is associated with remote and symptomatic intracerebral hemorrhage following intravenous thrombolysis. Considering the potential long-term adverse effects of CMBs progression, patients at a high risk of developing new CMBs should be identified based on potential risk factors.

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.

Low-density lipoprotein cholesterol, statin therapy, and cerebral microbleeds: The CIRCLE study

BACKGROUND

Current evidence suggests a potential association between cerebral microbleeds (CMBs), low-density lipoprotein cholesterol (LDL-C) levels, and statin use, but the exact relationship remains unclear. This study aims to prospectively examine these relationships in a stroke-free population.

METHODS

From January 2010 to January 2020, we enrolled stroke-free individuals with at least one cerebral small vessel disease imaging marker from the CIRCLE study (ClinicalTrials.gov ID: NCT03542734). Participants underwent baseline and 1-year follow-up susceptibility-weighted imaging (SWI), and baseline LDL-C testing. New CMBs were categorized as strictly lobar and deep CMBs based on location.

RESULTS

A total of 209 individuals were included. Baseline serum LDL-C levels were divided into quartiles: Q1 (≤1.76 mmol/L), Q2 (1.77-2.36 mmol/L), Q3 (2.37-2.93 mmol/L), and Q4 (>2.93 mmol/L). The incidence of new deep CMBs was 30.0%, 11.1%, 10.9%, 8.2% in Q1, Q2, Q3, Q4, respectively. Multivariate logistic model revealed that only LDL-C in Q1 was associated with increased incidence of new deep CMBs (OR = 4.256; 95% CI: 1.156-15.666; p = 0.029). In a subset of 169 participants without prior statin use, the use of atorvastatin was associated with reduced occurrence of new deep CMBs (OR = 0.181; 95% CI: 0.035-0.928; p = 0.040), while it was not found with rosuvastatin (OR = 0.808; 95% CI: 0.174-3.741; p = 0.785).

CONCLUSIONS

While lower LDL-C levels were associated with higher CMB development, statin therapy did not increase the risk of new CMBs. Atorvastatin even demonstrated a protective effect.

New Remote Cerebral Microbleeds on T2*-Weighted Echo Planar MRI After Intravenous Thrombolysis for Acute Ischemic Stroke

Background

The main and well-defined complication of intravenous administration of recombinant tissue plasminogen activator (tPA) in patients with acute ischemic stroke (AIS) is symptomatic intracranial hemorrhage (sICH). However, rtPA might also be connected with the formation of cerebral microbleeds (CMBs), located remotely from the ischemic lesions, that may remain clinically silent. This association might be important because the load of CMBs has been associated with cognitive impairment. We investigated whether administration of rtPA in AIS results in the appearance of new CMBs and if the initial load of CMBs is associated with hemorrhagic transformation.

Methods

A total of fifty-nine consecutive patients with AIS treated with rtPA underwent MRI including T2^*-weighted Echo Planar Imaging (T2^*-EPI) shortly before and 7–9 days after rtPA administration. We calculated the load of new CMBs located outside the MR diffusion restriction area in the follow-up imaging and assessed hemorrhagic transformation with ECASS-II scoring.

Results

A total of forty-nine patients were included for the final analysis. On initial T2^*-EPI-GRE, 37 baseline microbleeds (CMBs) were observed in 14 patients (28.6%). On follow-up T2^*-EPI-GRE amount of CMBs increased to a total number of 103. New CMBs were found in 5 (14.3%) of 35 patients without and in 9 (64.3%) of 14 with any baseline CMBs. Multiple logistic regression analysis indicated that presence of baseline CMBs (risk ratio [RR] 5.95, 95% CI 2.69–13.20, p < 0.001) and lower platelets level (risk ratio [RR] 0.992, 95% CI 0.986–0.998, p = 0.007) were independently associated with new CMBs. The baseline load of CMBs was not associated with the risk of hemorrhagic transformation.

Conclusion

In this study, new CMBs were found in nearly 30% of patients with AIS on the 7–9 days after rtPA treatment. Baseline CMBs correlated with a higher risk of new CMBs appearing after the rtPA treatment, independently of other factors. At the same time, in our sample, baseline CMBs did not correlate with an increased risk of hemorrhagic transformation. Since the associations between the CMBs load and cognitive impairment have already been proved, further studies are warranted to investigate possible associations between the thrombolytic treatment of patients with AIS, mainly those with baseline CMBs, and the risk of earlier cognitive decline.

Cerebral microbleeds development after stroke thrombolysis: A secondary analysis of the THAWS randomized clinical trial

BACKGROUND AND AIM

We determined to investigate the incidence and clinical impact of new cerebral microbleeds after intravenous thrombolysis in patients with acute stroke.

METHODS

The THAWS was a multicenter, randomized trial to study the efficacy and safety of intravenous thrombolysis with alteplase in patients with wake-up stroke or unknown onset stroke. Prescheduled T2*-weighted imaging assessed cerebral microbleeds at three time points: baseline, 22-36 h, and 7-14 days. Outcomes included new cerebral microbleeds development, modified Rankin Scale (mRS) ≥3 at 90 days, and change in the National Institutes of Health Stroke Scale (NIHSS) score from 24 h to 7 days.

RESULTS

Of all 131 patients randomized in the THAWS trial, 113 patients (mean 74.3 ± 12.6 years, 50 female, 62 allocated to intravenous thrombolysis) were available for analysis. Overall, 46 (41%) had baseline cerebral microbleeds (15 strictly lobar cerebral microbleeds, 14 mixed cerebral microbleeds, and 17 deep cerebral microbleeds). New cerebral microbleeds only emerged in the intravenous thrombolysis group (seven patients, 11%) within a median of 28.3 h, and did not additionally increase within a median of 7.35 days. In adjusted models, number of cerebral microbleeds (relative risk (RR) 1.30, 95% confidence interval (CI): 1.17-1.44), mixed distribution (RR 19.2, 95% CI: 3.94-93.7), and cerebral microbleeds burden ≥5 (RR 44.9, 95% CI: 5.78-349.8) were associated with new cerebral microbleeds. New cerebral microbleeds were associated with an increase in NIHSS score (p = 0.023). Treatment with alteplase in patients with baseline ≥5 cerebral microbleeds resulted in a numerical shift toward worse outcomes on ordinal mRS (median [IQR]; 4 [3-4] vs. 0 [0-3]), compared with those with <5 cerebral microbleeds (common odds ratio 17.1, 95% CI: 0.76-382.8). The association of baseline ≥5 cerebral microbleeds with ordinal mRS score differed according to the treatment group (p interaction = 0.042).

CONCLUSION

New cerebral microbleeds developed within 36 h in 11% of the patients after intravenous thrombolysis, and they were significantly associated with mixed-distribution and ≥5 cerebral microbleeds. New cerebral microbleeds development might impede neurological improvement. Furthermore, cerebral microbleeds burden might affect the effect of alteplase.

Predictors of new remote cerebral microbleeds after IV thrombolysis for ischemic stroke

OBJECTIVE

To assess the frequency, associated factors, and underlying vasculopathy of new remote cerebral microbleeds (CMB), as well as the risk of concomitant hemorrhagic complications related to new CMBs, after IV thrombolysis (IVT) in acute stroke patients.

METHODS

We conducted an observational study using data from our local thrombolysis registry. We included consecutive stroke patients with MRI (3T)-based IVT and a follow-up MRI the next day between 2008 and 2017 (n = 396). Only CMBs located outside of the ischemic lesions were considered. We also performed a meta-analysis on new CMBs after IVT that included 2 additional studies.

RESULTS

In our cohort, new remote CMBs occurred in 16/396 patients (4.0%) after IVT and the distribution was strictly lobar in 13/16 patients (81%). Patients with preexisting CMBs with a strictly lobar distribution were significantly more likely to have new CMBs after IVT (p = 0.014). In the random-effects meta-analysis (n = 741), the pooled cumulative frequency of new CMBs after IVT was 4.4%. A higher preexisting CMB burden (>2) was associated with a higher likelihood of new CMBs (odds ratio [OR] 3.6, 95% confidence interval [CI] 1.3-10.3) and new CMBs were associated with the occurrence of remote parenchymal hemorrhage (OR 28.8, 95% CI 8.6-96.4).

CONCLUSIONS

New remote CMBs after IVT occurred in 4% of stroke patients, mainly had a strictly lobar distribution, and were associated with IVT-related hemorrhagic complications. Preexisting CMBs with a strictly lobar distribution and a higher CMB burden were associated with new CMBs after IVT, which may indicate an underlying cerebral amyloid angiopathy.

Cerebral White Matter Hyperintensities and Microbleeds in Acute Ischemic Stroke: Impact on Recanalization Therapies. A Review of the Literature

Cerebral white matter hyperintensities (WMH) and cerebral microbleeds (CMBs) are frequently seen on brain imaging acquired for acute ischemic stroke. Given the raising use of recanalization therapies - both intravenous and endovascular - the interest on the impact of WMH and CMBs on the risk of intracerebral hemorrhage and on functional outcome is growing. In this review, we will discuss the relevance of WMH and CMBs among patients with an acute ischemic stroke, focusing on the implications for recanalization therapies.

Remote Intracerebral Hemorrhage Following Intravenous Thrombolysis in Pregnancy at 31 Weeks Gestation: A Case Report and Review of the Literature

INTRODUCTION

Intravenous recombinant tissue-type plasminogen activator thrombolysis in pregnancy for acute ischemic stroke is infrequent. As a rare complication of thrombolysis, remote intracerebral hemorrhage (rICH) whose mechanisms are unclear has not gained enough attention until now.

CASE REPORT

We present here a case of 26-year-old pregnant woman at 31 weeks gestation who suffered from sudden onset right-sided hemiparesis and slurred speech. She successfully received intravenous recombinant tissue-type plasminogen activator thrombolysis within 2.5 hours from stroke onset. Further workup demonstrated multiple and bilateral acute cerebral infarcts due to cardioembolism. At 6 hours after thrombolysis, multifocal intracerebral hemorrhages were developed in her left cerebellum and right temporal cortex, remote from the initial infarct areas. However, the patient achieved a final complete recovery of symptoms. Despite diffusion-weighted imaging could not confirm infarct in the areas of hemorrhages, multiple cerebral embolism was suggested to be involved in the etiology of rICH.

CONCLUSIONS

rICH is different from local intracerebral hemorrhage in its risk factors, neurological outcomes, and underlying mechanisms. Patients with rICH may have favorable outcomes and multiple cerebral embolism is still one of the important mechanisms for postthrombolytic rICH.

Cerebral microbleeds shouldn't dictate treatment of acute stroke: a retrospective cohort study evaluating risk of intracerebral hemorrhage

Background

Intravenous tissue plasminogen activator (IV tPA) after acute ischemic stroke carries the risk of symptomatic intracerebral hemorrhage (sICH). Cerebral microbleeds (CMBs) may indicate increased risk of hemorrhage and can be seen on magnetic resonance imaging (MRI). In this study, we examined the association between CMBs and sICH, focusing on the predictive value of their presence, burden, and location.

Methods

Records from all patients presenting to two academic stroke centers with acute ischemic stroke treated with IV tPA over a 5-year period were retrospectively reviewed. Demographic, medical, and imaging variables were evaluated. The presence, number, and location (lobar vs nonlobar) of CMBs were noted on gradient echo MRI sequences obtained during the admission. Univariable and multivariable statistical models were used to determine the relationship between CMBs and hemorrhagic (symptomatic and asymptomatic) transformation.

Results

Of 292 patients (mean age 62.8 years (SD 15.3), 49% African-American, 52% women), 21% (n = 62) had at least one CMB, 1% (n = 3) had > 10 CMBs, and 1% (n = 3) were diagnosed with probable cerebral amyloid angiopathy. After treatment, 16% (n = 46) developed hemorrhagic transformation, of which 6 (2%) were sICH. There was no association between CMB presence (p = .135) or location (p = .325) with sICH; however, those with a high CMB burden (> 10 CMB) were more likely to develop sICH (OR 37.8; 95% CI: 2.7–539.3; p = .007).

Conclusions

Our findings support prior findings that a high CMB burden (> 10) in patients with acute stroke treated with IV tPA are associated with a higher risk of sICH. However, the overall rate of sICH in the presence of CMB is very low, indicating that the presence of CMBs by itself should not dictate the decision to treat with thrombolytics.

Association Between Cerebral Microbleeds and Depression in the General Elderly Population: A Meta-Analysis

BACKGROUND

It remains unclear whether cerebral microbleeds (CMBs) are associated with depression in the general elderly population. We thus performed a meta-analysis to evaluate the relationship between depression and CMBs.

METHODS

A systematic literature search was conducted in EBSCO, PubMed, and Web of Science for relevant studies that assessed the relationship between depression and the prevalence of CMBs.

RESULTS

Five eligible studies including 7,328 patients were pooled in meta-analysis. The prevalence of CMBs was 18.0%. The prevalence of depression was 11.1%. The pooled analysis demonstrated odds ratio for CMBs and depression to be 1.187 (95% confidence interval 1.005-1.403; p = 0.043) with no evidence of statistical heterogeneity (I² = 0.0%, p = 0.621).

CONCLUSION

Our meta-analysis of available published data indicated an increased prevalence of depression in the subjects with pre-existing CMBs. This finding supports the vascular depression hypothesis. Further studies are needed to investigate the role of CMBs in the pathogenesis and progression of depression, which might provide a potential target for the prevention and treatment.

Clinical Outcome in Acute Ischemic Stroke Patients With Microbleeds After Thrombolytic Therapy: A Meta-Analysis

It remains unclear whether preexisting cerebral microbleeds (CMBs) increase the risks of worse functional outcome after thrombolytic therapy. We performed a systematic review and meta-analysis to assess the risk of unfavorable outcome in patients with acute ischemic stroke and CMBs.We searched EMBASE, PubMed, and Web of Science for relevant studies assessing functional outcome in the patients with CMBs following thrombolytic therapy. Fixed-effects and random-effects models were performed.Five eligible studies including 1974 patients were pooled in meta-analysis. The prevalence of CMBs was 24.3%. The pooled analysis demonstrates odds ratio for preexisting CMBs and the achievement of favorable outcome to be 0.69 (95% CI 0.56-0.86; P = 0.001) with no evidence of statistical heterogeneity (I = 46.7%, P = 0.112).Our meta-analysis of available published data demonstrates an increased risk of worse functional outcome after thrombolytic therapy for acute ischemic stroke in patients with pre-existing CMBs. Future studies are needed to determine whether the risk outweigh the expected benefit of reperfusion therapies.

New Cerebral Microbleeds After Mechanical Thrombectomy for Large-Vessel Occlusion Strokes

The interval appearance of cerebral microbleeds (CMBs) after endovascular treatment has never been described. We investigated the frequency and predictors of new CMBs that developed shortly after mechanical thrombectomy for acute ischemic stroke, and its impact on clinical outcome.We retrospectively analyzed patients with large-vessel occlusion strokes treated with Merci Retriever, Penumbra System, or stent-retriever devices. Serial T2*-weighted gradient-recall echo (GRE) magnetic resonance imaging (MRI) before and 48 h after endovascular thrombectomy were assessed to identify new CMBs. We examined independent factors associated with new CMBs after mechanical thrombectomy. We analyzed the association of the presence, burden, and distribution of new CMBs with clinical outcome.A total of 187 consecutive patients with serial GRE were enrolled in this study. CMBs were evident in 36 (19.3%) patients before mechanical thrombectomy. New CMBs occurred in 41 (21.9%) patients after mechanical thrombectomy. Of the 68 new CMBs, 45 appeared in the lobar location, 18 in the deep location and 5 in the infratentorial location. The presence of baseline CMBs was associated with new CMBs after mechanical thrombectomy (OR 5.38; 95% CI 2.13-13.59; P < 0.001), no matter whether the patients were treated primarily with mechanical thrombectomy or with intravenous thrombolysis followed by mechanical thrombectomy. Patients with new CMBs did not have increased rates of hemorrhagic transformation, in-hospital mortality, and modified Rankin Scale score 4 to 6 at discharge.New CMBs are common after mechanical thrombectomy in one-fifth of patients with acute ischemic stroke. Baseline CMBs before mechanical thrombectomy predicts the development of new CMBs. New CMBs after mechanical thrombectomy do not influence clinical outcome.

Imaging of cerebrovascular disorders: precision medicine and the collaterome

Imaging of stroke and neurovascular disorders has profoundly enhanced clinical practice and related research during the last 40 years since the introduction of computed tomography (CT) and magnetic resonance imaging (MRI) enabled mapping of the brain. We highlight recent advances in neurovascular imaging. We describe how the convergence of readily available data and new clinical trial paradigms will recast our methods for studying the neurovascular patient. The application of a precision medicine approach to the collaterome, a comprehensive synthesis of neurovascular pathophysiology, will entail novel methods for clinical trial randomization, collection of routine and clinical trial imaging results, data archiving, and analysis.