Prevalence and Associated Risk Factors of Cerebral Microbleeds in Egyptian Patients with Acute Ischemic Stroke and Atrial Fibrillation

Prevalence and Risk Factors of Cerebral Microbleeds among Egyptian Patients with Acute Ischemic Stroke

BACKGROUND

Cerebral microbleeds (CMBs) are markers of underlying hemorrhage-prone cerebral small vessel disease detected on MRI. They are associated with a heightened risk of stroke and cognitive decline. The prevalence of CMBs among Egyptian patients with ischemic stroke is not well studied. Our aim was to detect the prevalence of CMBs and associated risk factors among Egyptian patients with ischemic stroke.

METHODS

A prospective, cross-sectional, single-center study of consecutive patients with ischemic stroke. Patients were recruited between January 2021 and January 2022 at the Assiut University Hospital in the south of Egypt. Patients with known bleeding diathesis were excluded. All participants underwent full neurological assessment, urgent laboratory investigations, and MRI with T2* sequence.

RESULTS

The study included 404 patients, 191 (47.3%) of them were females. The mean age of the study population was 61 ± 1 years, and the mean NIHSS on admission was 12 ± 5. The prevalence of CMB was 26.5%, of whom 6.5% were young adults (age ≤45 years). CMBs were detected in 34.6% of patients with stroke caused by large artery atherosclerosis, 28.0% with small vessel disease stroke subtype, 25.2% with stroke of undetermined cause, and in 12.1% with cardioembolic stroke. History of AF, hypertension, dyslipidemia, Fazekas score >2, dual antiplatelet use, combined antiplatelet with anticoagulant treatment, and thrombolytic therapy remained independently associated with CMBs following multivariable regression analyses.

CONCLUSION

The high number of identified CMBs needs to inform subsequent therapeutic management of these patients. We are unable to determine whether the association between CMBs and antithrombotic use is a causal relationship or rather confounded by indication for these treatments in our observational study. To understand more about the underlying cause of this finding, more studies are needed.

The global burden of cerebral small vessel disease in low- and middle-income countries: A systematic review and meta-analysis

BACKGROUND

Cerebral small vessel disease (cSVD) is a major cause of stroke and dementia. Previous studies on the prevalence of cSVD are mostly based on single geographically defined cohorts in high-income countries. Studies investigating the prevalence of cSVD in low- and middle-income countries (LMICs) are expanding but have not been systematically assessed.

AIM

This study aims to systematically review the prevalence of cSVD in LMICs.

RESULTS

Articles were searched from the Ovid MEDLINE and EMBASE databases from 1 January 2000 to 31 March 2022, without language restrictions. Title/abstract screening, full-text review, and data extraction were performed by two to seven independent reviewers. The prevalence of cSVD and study sample size were extracted by pre-defined world regions and health status. The Risk of Bias for Non-randomized Studies tool was used. The protocol was registered on PROSPERO (CRD42022311133). A meta-analysis of proportion was performed to assess the prevalence of different magnetic resonance imaging markers of cSVD, and a meta-regression was performed to investigate associations between cSVD prevalence and type of study, age, and male: female ratio. Of 2743 studies identified, 42 studies spanning 12 global regions were included in the systematic review. Most of the identified studies were from China (n = 23). The median prevalence of moderate-to-severe white matter hyperintensities (WMHs) was 20.5%, 40.5%, and 58.4% in the community, stroke, and dementia groups, respectively. The median prevalence of lacunes was 0.8% and 33.5% in the community and stroke groups. The median prevalence of cerebral microbleeds (CMBs) was 10.7% and 22.4% in the community and stroke groups. The median prevalence of moderate-to-severe perivascular spaces was 25.0% in the community. Meta-regression analyses showed that the weighted median age (51.4 ± 0.0 years old; range: 36.3-80.2) was a significant predictor of the prevalence of moderate-to-severe WMH and lacunes, while the type of study was a significant predictor of the prevalence of CMB. The heterogeneity of studies was high (>95%). Male participants were overrepresented.

CONCLUSIONS

This systematic review and meta-analysis provide data on cSVD prevalence in LMICs and demonstrated the high prevalence of the condition. cSVD research in LMICs is being published at an increasing rate, especially between 2010 and 2022. More data are particularly needed from Sub-Saharan Africa and Central Europe, Eastern Europe, and Central Asia.

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.