Presence Of Cerebral Microbleeds In Patients Research Articles

Logistic regression model for predicting risk factors and contribution of cerebral microbleeds using renal function indicators

BackgroundThe brain and kidneys share similar low-resistance microvascular structures, receiving blood at consistently high flow rates and thus, are vulnerable to blood pressure fluctuations. This study investigates the causative factors of cerebral microbleeds (CMBs), aiming to quantify the contribution of each risk factor by constructing a multivariate model via stepwise regression.MethodsA total of 164 hospitalized patients were enrolled from January 2022 to March 2023 in this study, employing magnetic susceptibility-weighted imaging (SWI) to assess the presence of CMBs. The presence of CMBs in patients was determined by SWI, and history, renal function related to CMBs were analyzed.ResultsOut of 164 participants in the safety analysis, 36 (21.96%) exhibited CMBs and 128 (78.04%) did not exhibit CMBs, and the median age of the patients was 66 years (range: 49–86 years). Multivariate logistic regression identified hypertension (OR = 13.95%, 95% CI: 4.52, 50.07%), blood urea nitrogen (BUN) (OR = 1.57, 95% CI: 1.06–2.40), cystatin C (CyC) (OR = 4.90, 95% CI: 1.20–22.16), and urinary β-2 microglobulin, (OR = 2.11, 95% CI: 1.45–3.49) as significant risk factors for CMBs. The marginal R-square (RM2) was 0.25. Among all determinants, hypertension (47.81%) had the highest weight, followed by UN (11.42%). Quasi-curves plotted using the bootstrap method (999 times) showed good agreement between the predictive model and actual observations.ConclusionHypertension, BUN, urinary β-2 microglobulin, CyC were risk factors for CMBs morbidity, and controlling the above indicators within a reasonable range will help to reduce the incidence of CMBs.

Abstract 17284: Prognostic Impact of Silent Cerebral Microbleeds in Patients Undergoing Transcatheter Aortic Valve Replacement

Introduction: Cerebral microbleeds (CMBs) are known to be associated with age, various cardiovascular risk factors, cognitive impairment, the use of antithrombotic drugs, and future neurological or cardiovascular events. Transcatheter aortic valve implantation (TAVR) has emerged as a rapidly evolving treatment for patients with severe aortic stenosis (AS). However, data on CMBs in those patients are scarce. Hypothesis: We hypothesized that the presence of CMBs in patients with severe aortic stenosis (AS) undergoing TAVR may be associated with some clinical factors or have prognostic implications. Methods: A retrospective analysis was conducted on data from 137 consecutive patients (mean age: 84 ± 5 years, 55 male) with severe AS who underwent T2*-weighted brain magnetic resonance imaging (MRI) prior to TAVR. The brain MRI was assessed by researchers blinded to the patients' clinical information. Additionally, conventional echocardiography was performed to evaluate left ventricular function and valvular abnormalities. Results: CMBs were identified in 42 out of 137 patients (31%). No significant differences were observed between patients with and without CMBs in age, gender, serum BNP levels, or antiplatelet/anticoagulant therapy. However, there were significant differences in left ventricular ejection fraction (LVEF) and left ventricular end-systolic volume (LVESV) between the two groups (LVEF: 58 ± 14% vs. 64 ± 10%, p = 0.01; LVESV: 38 ± 25 ml vs. 28 ± 16 ml, p < 0.01, respectively). Over a median follow-up period of 618 days, patients with CMBs had a higher incidence of major adverse cardiac events (defined as death or heart failure re-hospitalization) compared to those without CMBs (24.0% vs. 13.0%, log-rank test, p = 0.04). (Figure). Conclusions: Our study reveals a high prevalence of CMBs in patients with severe AS. The presence of CMBs is associated with lower LVEF, increased LVESV, and poor prognosis following TAVR.

Abstract WP417: Relevance of Lobar Cerebral Microbleeds in Patients With Deep Intracerebral Hemorrhage

Background: Markers of cerebral small vessel disease (cSVD) severity and prognosis in strictly lobar or strictly deep intracerebral hemorrhages (ICH)/cerebral microbleeds (CMB) are well defined but data are scarce for mixed-location ICH/CMB. We aimed to compare neuroimaging features and outcomes between deep ICH patients with and without lobar CMBs. Methods: Patients with first-ever deep ICH from a prospectively maintained single-center registry were analyzed. Demographics, risk factors and neuroimaging markers of cSVD including CMBs, cortical superficial siderosis, enlarged perivascular spaces (EPVS), white matter hyperintensity volumes (WMH) and brain atrophy scores (range 0-15) were compared between deep ICH patients with lobar CMBs and those without lobar CMBs. The follow-up data were analyzed for ICH recurrence, ischemic stroke (IS) and all-cause mortality. Results: Of 208 patients, 98 (47.1%) had lobar CMBs. Patients with L-CMBs were older (65.3±12.1 vs. 57.4±12.5, p<0.001) and more likely to be hypertensive (98% vs. 90.9%, p=0.037) than those without L-CMBs. Deep CMBs (83.7% vs 56.4%, p<0.001), lacunes (53.1% vs 31.8%, p=0.003) and severe basal ganglia EPVS (40.8% vs 17.3%, p<0.001) were more common in patients with L-CMBs. Patients with L-CMBs had higher volumes of WMH (17.4 ml [IQR 9-38] vs 4.8 ml [IQR 1-13], p<0.001) and atrophy scores (4 [IQR 2-7] vs 3 [IQR 0-6], p=0.007) as compared to patients without L-CMBs. During a median follow-up of 21 months, the ICH recurrence rate was similar between groups (p=0.2), but higher incident IS (3.0 vs 0.0 per 1000-person-months, p=0.016) and all-cause mortality (4.9 vs 1.5 per 1000-person-months, p=0.026) were observed in patients with L-CMBs. In a cox regression model, the presence of lobar CMBs was independently associated with a composite outcome measure (ICH/IS/mortality) after adjusting for age, hypertension, WMH volume, lacune, BG-EPVS and atrophy scores (odds ratio: 2.9, 95%CI:1.01-8.4 p=0.046). Conclusions: Presence of lobar CMBs in patients with deep ICH is associated with parenchymal markers of more severe cSVD and poor prognosis, suggesting a more advanced vasculopathy compared to patients with strictly deep ICH.

Increased prevalence of cerebral microbleeds in patients with low left ventricular systolic function.

Gradient-echo T2-star (T2*)-weighted magnetic resonance imaging (MRI) is a sensitive method to detect cerebral microbleeds (CMBs). The presence of CMBs was reported to be a marker of future cardiovascular mortality and is associated with various cardiovascular risk factors, use of antithrombotic drugs, and cognitive dysfunction. However, the relationship between cardiac function and CMBs remains unclear. We investigated the association between cardiac function and presence of CMBs in patients with cardiovascular diseases. This single-center retrospective study included a total of 424 participants (mean age 70 ± 12years; men 286 (67%); mean left ventricular ejection fraction (LVEF) 61% ± 12%] who underwent echocardiography and brain T2*-weighted MRI within 1 month without neurologic abnormality. CMBs were found in 118 (28%) patients. There was no significant relationship between CMBs and anticoagulant or antiplatelet therapy. LVEF was significantly lower in patients with CMBs than in those without CMBs (59% ± 13% vs. 62% ± 11%, P < 0.05). On multivariate logistic analysis, lower LVEF [odds ratio (OR) 0.98, 95% confidence interval (CI) 0.96-1.00; P < 0.05] and age (OR 1.02, 95% CI 1.00-1.05; P < 0.05) were significantly associated with CMBs. The presence of CMBs was frequently observed in the patients with cardiovascular disease and was significantly associated with age and LVEF.

Cerebral Microbleeds: Imaging and Clinical Significance.

Cerebral microbleeds (CMBs), also referred to as microhemorrhages, appear on magnetic resonance (MR) images as hypointense foci notably at T2*-weighted or susceptibility-weighted (SW) imaging. CMBs are detected with increasing frequency because of the more widespread use of high magnetic field strength and of newer dedicated MR imaging techniques such as three-dimensional gradient-echo T2*-weighted and SW imaging. The imaging appearance of CMBs is mainly because of changes in local magnetic susceptibility and reflects the pathologic iron accumulation, most often in perivascular macrophages, because of vasculopathy. CMBs are depicted with a true-positive rate of 48%-89% at 1.5 T or 3.0 T and T2*-weighted or SW imaging across a wide range of diseases. False-positive "mimics" of CMBs occur at a rate of 11%-24% and include microdissections, microaneurysms, and microcalcifications; the latter can be differentiated by using phase images. Compared with postmortem histopathologic analysis, at least half of CMBs are missed with premortem clinical MR imaging. In general, CMB detection rate increases with field strength, with the use of three-dimensional sequences, and with postprocessing methods that use local perturbations of the MR phase to enhance T2* contrast. Because of the more widespread availability of high-field-strength MR imaging systems and growing use of SW imaging, CMBs are increasingly recognized in normal aging, and are even more common in various disorders such as Alzheimer dementia, cerebral amyloid angiopathy, stroke, and trauma. Rare causes include endocarditis, cerebral autosomal dominant arteriopathy with subcortical infarcts, leukoencephalopathy, and radiation therapy. The presence of CMBs in patients with stroke is increasingly recognized as a marker of worse outcome. Finally, guidelines for adjustment of anticoagulant therapy in patients with CMBs are under development. © RSNA, 2018.

Independent Correlation of Serum Homocysteine with Cerebral Microbleeds in Patients with Acute Ischemic Stroke due to Large-Artery Atherosclerosis

The severity of cerebral microbleeds (CMBs) affected the prognosis of patients with acute cerebrovascular disease. Considering the impact of CMBs on clinical decision, it is necessary to assess the risk factors of CMBs. We aimed to evaluate the independent risk factors of CMBs in patients with acute ischemic stroke of large-artery atherosclerosis. 112 patients were enrolled in the study. The baseline information, the results of laboratory examination and cranial MRI were collected. The independent risk factors of CMBs in patients with acute ischemic stroke due to large-artery atherosclerosis were evaluated. CMBs were found in 56 (50%) patients. Older age and higher homocysteine (Hcy) level were associated with an elevated chance of occurrence of CMBs. Further, there was a positive correlation between CMBs grade and serum Hcy level. Serum Hcy level is strongly associated with the presence of CMBs in patients with acute ischemic stroke due to large-artery atherosclerosis. Serum Hcy level may be a potential therapeutic target for alleviating adverse clinical outcomes of CMBs.

Association of serum vascular endothelial growth factor levels and cerebral microbleeds in patients with Alzheimer's disease.

The association between the presence of cerebral microbleeds (CMBs) and serum vascular endothelial growth factor (VEGF) levels in patients with Alzheimer's disease (AD) was investigated. Consecutive AD patients who underwent magnetic resonance examination with susceptibility-weighted imaging (SWI) were prospectively examined. The presence of CMBs on SWI was independently interpreted. The number and location of microbleeds were assessed. Demographics including age, sex and risk factors were obtained. Serum VEGF levels were measured with an enzyme-linked immunosorbent assay. Of the 146 AD patients included, 47 (32.2%) patients had CMBs on SWI. The CMBs were most commonly located in strictly lobar locations (29/47, 61.7%). The mean VEGF levels were higher in the patients with CMBs than in those without (336.72 ± 15.18 vs. 192.37 ± 11.34 pg/ml). Multivariate logistic regression analyses showed that, for each 10 pg/ml increase of VEGF levels, there was a significant increase in the presence of CMBs after adjusting for age and sex, and after additional adjustment for cardiovascular risk factors, silent lacunar infarction and white matter hyperintensity in patients with AD (odds ratio 2.37; 95% confidence interval 1.53-4.02, P = 0.004). Serum VEGF levels are associated with the presence of CMBs in patients with AD.

Quantity of Cerebral Microbleeds, Antiplatelet Therapy, and Intracerebral Hemorrhage Outcomes: A Systematic Review and Meta-analysis

Cerebral microbleeds (CMBs) increase future intracerebral hemorrhage (ICH) risk after ischemic stroke (IS) or transient ischemic attack (TIA). However, whether CMB-related ICH risk depends on CMB quantity, CMB location, or antithrombotic agents is unclear. We performed a systematic review and meta-analysis to investigate CMB-related ICH risk, stratifying patients according to the quantity of CMB, the location of CMB, and the type of antithrombotic therapy used. Literature databases were searched for prospective cohorts reporting ICH outcomes in patients with IS or TIA with baseline CMB evaluation. We calculated pooled relative ratios (RRs) for ICH among patients with and without CMBs. Pooled RRs of CMB-related ICH were further calculated in subgroups stratified by CMB quantity, CMB location, and antithrombotic therapy. Among the 10 included studies, the pooled RR of future ICH was 7.73 (95% confidence interval [CI], 4.07-14.70; P < .001) in CMB versus non-CMB patients. Subgroup analysis revealed that compared with non-CMB patients, multiple-CMB patients were at an increased risk for future ICH (RR = 8.02; 95% CI, 3.21-20.01; P < .001), whereas single-CMB patients did not incur this risk (RR = 2.33; 95% CI, .63-8.63; P = .205). A strong association was found between CMB presence and subsequent ICH in antiplatelet users (RR = 16.56; 95% CI, 3.68-74.42; P < .001). Studies on CMB-related ICH according to CMB locations and in anticoagulant users are lacking for subgroup analysis. Our study revealed that patients with IS or TIA with multiple CMBs may incur a higher risk of future ICH, and the presence of CMBs in patients with IS or TIA using antiplatelet agents may significantly increase the subsequent ICH risk.

Cerebral Microbleeds in Nonlacunar Brain Infarction Are Associated with Lower Coated–Platelet Levels

Coated-platelets are a subset of platelets with high procoagulant potential observed on dual-agonist stimulation with collagen and thrombin. Coated-platelet levels are elevated in patients with nonlacunar ischemic stroke compared with controls, although the presence of early hemorrhagic transformation is associated with lower coated-platelet levels. In contrast to infarction, patients with spontaneous intracerebral hemorrhage have lower coated-platelet levels, and these levels inversely correlate with bleed size. Cerebral microbleeds (CMBs) represent previous small hemorrhagic occurrences. We undertook a pilot study to investigate coated-platelet production and the presence of CMBs in patients with nonlacunar ischemic stroke. Coated-platelet levels were determined in 110 consecutive patients with a diagnosis of nonlacunar stroke. Microbleeds were identified using the published criteria by an experienced stroke neurologist. Coated-platelet levels were compared statistically between patients with and without CMBs using thenonparametric Wilcoxon rank sum test. Coated-platelet levels (median [interquartile range]) for all patients were 44.1% [34%-51.2%]. CMBs were detected in 22 patients (20%); these patients had significantly lower coated-platelet levels compared with those without CMBs (35.6% [22.6%-47.2%] versus 45.1% [36.1%-51.5%]; P=.025), whereas other demographic and clinical factors did not differ significantly. The presence of CMBs in patients with nonlacunar ischemic stroke is associated with lower levels of coated-platelets. Larger prospective studies are needed to better establish the potential connection between altered coated-platelet synthesis, microbleeds, cerebral infarction, and possible hemorrhage-prone vascular changes.