Higher ambulatory blood pressure relates to new cerebral microbleeds: 2-year follow-up study in lacunar stroke patients.

BACKGROUND AND PURPOSE: Elevated blood pressure (BP) is associated with the presence of cerebral microbleeds (CMBs) in cross-sectional studies. However, longitudinal studies did not show a convincing relationship. We aimed to determine the association between elevated BP levels and the occurrence of new CMBs after a 2-year follow-up in first-ever lacunar stroke patients using ambulatory BP monitoring. METHODS: Ninety-six first-ever lacunar stroke patients underwent brain MRI and ambulatory BP monitoring at baseline and after 2-year follow-up. We used logistic regression analyses to assess the association of BP levels with new CMBs. RESULTS: We found new CMBs in 17 patients (18%). Higher 24-hour, day and night systolic BP (odds ratio, 2.69; 95% confidence interval, 1.40-5.21 per SD increase for 24-hour BP) and diastolic BP (odds ratio, 2.13; 95% confidence interval, 1.15-3.90 per SD increase for 24-hour BP) at baseline were associated with the development of new CMBs independent of age and sex. BP levels decreased during follow-up in both patients with and without new CMBs. Unlike BP levels at baseline, there was no difference in BP levels at follow-up between patients with and without new CMBs. CONCLUSIONS: Both higher systolic and diastolic BP levels were associated with the development of new CMBs in a population of lacunar stroke patients. Decrease of BP levels during follow-up did not halt progression of CMBs; however, it remains to be determined whether (early) intervention with antihypertensive drugs can slow down progression of CMBs.

Ambulatory blood pressure in patients with lacunar stroke: association with total MRI burden of cerebral small vessel disease.

BACKGROUND AND PURPOSE: Asymptomatic lacunar infarcts, white matter lesions, cerebral microbleeds, and enlarged perivascular spaces are MRI markers of cerebral small vessel disease (cSVD). Higher blood pressure (BP) levels are associated with the presence of these markers separately, but the association with the total burden of cSVD on brain MRI, expressed by the simultaneous presence of multiple markers of cSVD (a compound score), has not been investigated. METHODS: We performed 24-hour ambulatory BP monitoring in 122 patients with first-ever lacunar stroke. On brain MRI, we scored the presence of each marker of cSVD. One point was awarded for the presence of each marker, producing a score between 0 and 4. Associations with BP levels were tested with ordinal regression analyses. RESULTS: Eighteen (15%) patients had no markers of cSVD, and 6 (5%) patients had 4 markers. Most patients (45; 37%) had 2 different markers. After correction for age and sex, higher 24-hour, day, and night systolic (24-hour odds ratio, 1.25; 95% confidence interval, 1.02-1.52 per 10 mm Hg) and diastolic (24-hour odds ratio, 1.32; 95% confidence interval, 1.12-1.56 per 5 mm Hg) BP were all significantly associated with an increasing total burden of cSVD. CONCLUSIONS: We found a positive association of ambulatory BP levels with total burden of cSVD on brain MRI. With increasing BP levels, there is a piling up of damage in the brain. We suggest that further cSVD studies also consider viewing the total burden in addition to each of the MRI markers separately.

Family history of stroke is an independent risk factor for lacunar stroke subtype with asymptomatic lacunar infarcts at younger ages.

BACKGROUND AND PURPOSE: Results from case-control and case-case studies indicate that a positive family history of stroke (FHstroke) is an independent risk factor for lacunar stroke. Different lacunar stroke phenotypes can be distinguished on the basis of the presence of asymptomatic lacunar infarcts (aLACs), ischemic white-matter lesions, or brain microbleeds. The aim of the present study was to determine whether familial aggregation of stroke was different for lacunar stroke phenotypes. METHODS: In 157 patients with a first-ever lacunar stroke, a complete first-degree FHstroke was obtained by a standardized questionnaire and additional interview. Lacunar stroke patients were categorized successively into groups, depending on the presence of aLACs, ischemic white-matter lesions, and brain microbleeds on magnetic resonance imaging. RESULTS: Fifty-two percent of patients reported a positive FHstroke in at least one of their first-degree relatives. In younger (<65 years) probands, a high frequency of parental FHstroke (59% versus 20%, P<0.01) in those with aLACs compared with probands without aLACs was found. In multivariate analysis, the strongest associations were found for parental FHstroke (odds ratio=6.46; 95% CI=1.96 to 21.33), maternal FHstroke (odds ratio=4.00; 95% CI=1.18 to 13.56), and paternal FHstroke (odds ratio=5.40; 95% CI=1.14 to 25.61). CONCLUSIONS: A family history of stroke might be an independent risk factor for the lacunar stroke phenotype with aLACs at younger ages, suggesting a role for genetic factors in this phenotype caused by diffuse vasculopathy.

Autoantibodies against oxidized low-density lipoprotein in cerebral small vessel disease.

BACKGROUND AND PURPOSE: Oxidized low-density lipoprotein (oxLDL) induces endothelial dysfunction and antibody formation. Because endothelial dysfunction is involved in cerebral small vessel disease (CSVD) (dilated Virchow Robin spaces, lacunar infarcts, and white matter lesions), oxLDL antibodies could play a role in CSVD pathogenesis. Therefore, we studied oxLDL antibodies in patients with high prevalence of CSVD: lacunar stroke patients and essential hypertensive patients. METHODS: A total of 158 lacunar stroke patients, 158 hypertensive patients, and 43 healthy controls were included. We determined levels of IgG and IgM against hypochlorite (HOCl) and malondialdehyde (MDA) oxLDL using ELISA (values in optical density). RESULTS: Patients with CSVD had higher levels of IgG-HOCl-oxLDL (0.77 versus 0.70; P<0.01), as well as lower levels of IgM-MDA-oxLDL (0.55 versus 0.65; P<0.05) than patients without such lesions. Higher IgG-HOCl-oxLDL levels were only independently associated with higher numbers of Virchow Robin spaces at the level of the basal ganglia (ß=0.218; P<0.001). CONCLUSIONS: An autoinflammatory process with lower levels of IgM antibodies and higher levels of IgG antibodies against oxLDL may be involved in CSVD.

Endothelial activation in lacunar stroke subtypes.

BACKGROUND AND PURPOSE: Lacunar stroke (LS) can be subtyped according to the absence (isolated lacunar infarct [ILA]) or presence of concomitant white matter lesions (WML) and/or asymptomatic lacunar infarcts. Endothelial activation is thought to play a pivotal role in the subtype with WML and/or asymptomatic lacunar infarcts. The aim of this study was to evaluate whether endothelial activation is associated with WML and/or asymptomatic lacunar infarcts in LS patients. Here, we determined levels of circulating blood markers of endothelial function in LS patients. METHODS: In 149 patients, all of whom had brain-MRI, levels of tissue plasminogen activator (tPA), plasminogen activator inhibitor type 1 (PAI-1), tPA-PAI-1 complex, von Willebrand factor, tissue factor, thrombomodulin, and coagulation factor VIII were determined. Levels of blood markers were related to subtypes of LS and adjusted for age, gender, and vascular risk factors. RESULTS: In subtypes of LS, tPA activity was increased in patients with WML (0.79 IU/mL vs 0.44 IU/mL for ILA; P=0.02) and PAI-1-antigen levels were lowest in patients with WML (27.5 ng/mL vs 44.0 ng/mL for ILA; P=0.02). The association between WML and PAI-1 remained significant after multivariable analysis (OR, 0.99; 95% CI, 0.98-1.00 per ng/mL change of PAI-1; P=0.04). CONCLUSIONS: We found further evidence for the hypothesis of endothelial activation in the subtype of LS caused by a diffuse small vessel vasculopathy, as we found higher levels of tPA in patients with concomitant extensive WML than in those with ILA. Second, low levels of PAI-1 were associated with WML. We postulate that differences in activity of components of the fibrinolytic system might contribute to WML development.

The likelihood of decreasing strokes in atrial fibrillation patients by strict application of guidelines.

AIMS: Despite the known increased stroke risk associated with AF and the benefit of oral anticoagulation (OAC) in high-risk patients, still approximately 20% of all ischaemic strokes are atrial fibrillation (AF) related. We aimed to evaluate the frequency of inappropriate anticoagulation in all patients admitted with AF associated ischaemic stroke and calculate the theoretical number of preventable strokes in case of proper guideline adherence and assess secondary stroke prevention at discharge. METHODS AND RESULTS: In this cross-sectional study, all patients with ischaemic strokes admitted to our hospital during May 2003-August 2006 in whom the diagnosis AF was either known or established during hospital stay were identified. We studied if their admission and discharge antithrombotic therapy was in accordance with the published guidelines. Subsequently, we calculated the number of preventable strokes in case AF patients would have received adequate antithrombotic treatment on admission. On admission, in 51% of the OAC eligible known AF patients the drug was withheld. Improved antithrombotic guideline adherence potentially would have prevented 20 out of the 89 (22%) ischaemic strokes. At discharge at least 10% of the patients were still insufficiently protected against recurrent stroke. CONCLUSION: Many known AF patients admitted with ischaemic stroke lack adequate antithrombotic treatment on admission. Antithrombotic guideline adherence in these patients has the potential to prevent a substantial number strokes. Secondary stroke prevention at discharge is also suboptimal.

Brain microbleeds relate to higher ambulatory blood pressure levels in first-ever lacunar stroke patients.

BACKGROUND AND PURPOSE: Hypertension is an important risk factor for brain microbleeds (BMBs) in lacunar stroke patients. However, beyond the qualitative label "hypertension," little is known about the association with ambulatory blood pressure (BP) levels. METHODS: In 123 first-ever lacunar stroke patients we performed 24-hour ambulatory BP monitoring after the acute stroke-phase. We counted BMBs on T2*-weighted gradient-echo MR images. Because a different etiology for BMBs according to location has been suggested, we distinguished between BMBs in deep and lobar location. RESULTS: BMBs were seen in 36 (29.3%) patients. After adjusting for age, sex, number of antihypertensive drugs, asymptomatic lacunar infarcts, and white matter lesions, we found 24-hour, day, and night systolic and diastolic BP levels to be significantly associated with the presence and number of BMBs (odds ratios 1.6 to 2.3 per standard deviation increase in BP). Distinguishing between different locations, various BP characteristics were significantly associated with the presence of deep (or combined deep and lobar) BMBs, but not with purely lobar BMBs. CONCLUSIONS: Our results underline the role of a high 24-hour BP load as an important risk factor for BMBs. The association of BP levels with deep but not purely lobar BMBs is in line with the idea that different vasculopathies might be involved. Deep BMBs may be a particular marker of BP-related small vessel disease, but longitudinal and larger studies are now warranted to substantiate these findings.

Endothelial dysfunction in lacunar stroke: a systematic review.

BACKGROUND: Endothelial dysfunction is thought to play an important role in the pathogenesis and progression of cerebral small-vessel disease in lacunar stroke patients. METHODS: We systematically searched the literature (MEDLINE, EMBASE) for evidence of endothelial activation and dysfunction in lacunar stroke. The selected papers were assessed by a predefined checklist to estimate methodological and informative quality. The papers were categorized into subheadings concerning the different physiologic functions of the endothelium and a subheading concerning toxins for the endothelium. RESULTS: 29 articles were eligible for further analysis. We found 16 publications on regulation of vascular tone by the endothelium, which showed an impaired function at several time points after the stroke by means of different clinical methods (e.g. flow-mediated vasodilatation and CO2 reactivity). Nine references showed elevated levels of markers of hemostatic function of the vascular endothelium (e.g. von Willebrand factor, thrombomodulin) in acute and subsequent phases. In 4 papers, adhesion molecules (e.g. E- and P-selectin) were elevated only during the acute phase. Homocysteine, a toxin for the endothelium, was elevated in patients in 3 papers. CONCLUSIONS: The current literature suggests that endothelial dysfunction might be involved in the pathogenesis of lacunar stroke, especially in those patients with concomitant silent lacunar infarcts and ischemic white matter lesions. Future research on endothelial function in lacunar stroke should concentrate on long-term clinical as well as radiological follow-up in well-defined cases and combine multiple methods to evaluate endothelial function.

Plasma tPA-Activity and Progression of Cerebral White Matter Hyperintensities in Lacunar Stroke Patients.

INTRODUCTION: Tissue plasminogen activator (tPA)-activity and plasminogen activator inhibitor type 1 (PAI-1) antigen are considered to be haemostasis-related markers of endothelial activation and relate to presence of cerebral white matter hyperintensities (WMH) as was earlier shown in a cross-sectional study. We investigated whether tPA-activity and PAI-1 levels are associated with WMH progression in a longitudinal study. METHODS: In 127 first-ever lacunar stroke patients in whom baseline brain MRI and plasma levels of tPA-activity and PAI-1-antigen were available, we obtained a 2-year follow-up MRI. We assessed WMH progression by a visual WMH change scale. We determined the relationship between levels of tPA-activity and PAI-1 and WMH progression, by logistic regression analysis. RESULTS: Plasma tPA-activity was associated with periventricular WMH progression (OR 2.36, 95% CI 1.01-5.49, with correction for age and sex and baseline presence of WMH), but not with deep or any (periventricular and/or deep) WMH progression. PAI-1 levels were lower in patients with WMH progression, but these results were not significant. CONCLUSION: We found a relationship between plasma tPA-activity and progression of periventricular WMH. More research is needed to determine whether there is a (direct) role of tPA in the development and progression of WMH.

Higher ambulatory blood pressure relates to enlarged Virchow-Robin spaces in first-ever lacunar stroke patients.

Enlarged Virchow-Robin spaces (EVRS) are considered to be a sign of cerebral small vessel disease. Hypertension is an important risk factor for cerebral small vessel disease, whereas ambulatory blood pressure (BP) is the strongest predictor of hypertension-related brain damage. However, the association between ambulatory BP levels and EVRS has never been investigated. The aim of this study was to determine the association between ambulatory BP levels and EVRS. In 143 first-ever lacunar stroke patients, we performed 24-h ambulatory BP monitoring after the acute stroke phase. On brain MRI we counted EVRS in the basal ganglia and the centrum semiovale. We graded the number of EVRS at each level into a three-category severity scale. We assessed the association between BP levels and EVRS by ordinal regression analysis. After adjusting for age, sex, extensive white matter lesions, and asymptomatic lacunar infarcts, higher day systolic (OR 1.21; 95 % CI 1.00-1.46 per 10 mmHg), day diastolic (1.18; 95 % CI 1.02-1.37 per 5 mmHg) and 24-h diastolic (OR 1.18; 95 % CI 1.01-1.37 per 5 mmHg) ambulatory BP levels were associated with EVRS at the basal ganglia level. No relation was found between ambulatory BP levels and EVRS in the centrum semiovale. Higher day ambulatory BP levels are associated with EVRS in the basal ganglia. This association was independent of the presence of extensive white matter lesions and asymptomatic lacunar infarcts. Our results imply that basal ganglia EVRS should be regarded as a separate manifestation of BP-related brain damage.

Vascular inflammation in cerebral small vessel disease.

Cerebral small vessel disease (CSVD) is considered to be caused by an increased permeability of the blood-brain barrier and results in enlargement of Virchow Robin spaces (VRs), white matter lesions, brain microbleeds, and lacunar infarcts. The increased permeability of the blood-brain barrier may relate to endothelial cell activation and activated monocytes/macrophages. Therefore, we hypothesized that plasma markers of endothelial activation (adhesion molecules) and monocyte/macrophage activation (neopterin) relate to CSVD manifestations. In 163 first-ever lacunar stroke patients and 183 essential hypertensive patients, we assessed CSVD manifestations on brain magnetic resonance imaging (MRI) and levels of C-reactive protein (CRP), neopterin, as well as circulating soluble adhesion molecules (sICAM-1, sVCAM-1, sE-selectin, sP-selectin). Neopterin, sICAM-1 and sVCAM-1 levels were higher in patients with extensive CSVD manifestations than in those without (p < 0.01). Neopterin levels independently related to higher numbers of enlarged Virchow Robin spaces (p < 0.001). An inflammatory process with activated monocytes/macrophages may play a role in the increased permeability of the blood brain barrier in patients with CSVD.

Estimating the magnitude of genetic factors by calculating the genetic relative risk of stroke in first-ever lacunar stroke patients.

BACKGROUND: Positive family history of stroke is an independent risk factor for lacunar stroke. However, the magnitude of familial aggregation of a certain disease is better evaluated by the genetic relative risk. This is calculated by dividing the prevalence of specific disease in family members of patients by the prevalence of this disease in the general population. In a cohort of lacunar stroke patients, who were subtyped clinically and radiologically, we determined the genetic relative risk of stroke. METHODS: By questionnaire and additional interview, we obtained a complete first-degree family history of stroke. The prevalence of stroke in first-degree relatives of these lacunar stroke patients was compared to the self-reported prevalence of stroke in a Dutch community based cohort of elderly volunteers. Secondly, the influence of proband characteristics and family composition on parental and sibling history of stroke were evaluated. PRINCIPAL FINDINGS: We collected data of 1066 first-degree relatives of 195 lacunar stroke patients. Strokes occurred in 13.5% of first-degree relatives. The genetic relative risk was 2.94 (95%CI 2.45-3.53) for overall first-degree relatives, 4.52 (95%CI 3.61-5.65) for patients' parents and 2.10 (95%CI 1.63-2.69) for patients' siblings. Age of proband and proband status for hypertension influenced the chance of having a parent with a history of stroke whereas the likelihood of having a concordant sibling increased with sibship size. CONCLUSIONS: We found an increased genetic relative risk of stroke in first-degree relatives of patients with lacunar stroke. Our data warrant further genomic research in this well-defined high risk population for stroke.

Haptoglobin polymorphism and lacunar stroke.

Haptoglobin (Hp) 2-2 phenotype has been associated with peripheral and coronary artery disease and risk of vascular complications in diabetic patients, but any association of Hp polymorphism with cerebrovascular disease has not been explored so far. We aimed to study Hp polymorphism in a sample of 124 patients with a rather homogeneous type of cerebrovascular disease, namely first symptomatic lacunar stroke due to small vessel disease, in comparison with a large (n=918) control group. Hp phenotypes were determined using starch gel electrophoresis. Hp1 allele frequency was significantly higher in patients than in controls (0.480 vs. 0.395, p<0.05), mainly due to a lower Hp2-2 phenotype frequency (25.0 vs. 36.3 %; OR 0.59; 95%CI 0.38-0.90; p<0.05). This was even more pronounced in younger (

A SELDI-TOF-MS study in Lacunar Stroke with Subsequent Haptoglobin Phenotyping.

Using Surface-Enhanced Laser Desorption / Ionization Time-of-Flight Mass Spectrometry (SELDI-TOF-MS), we aimed to detect differences in protein profile in serum samples of two lacunar stroke subtypes. SELDI-TOF-MS, followed by protein identification, was performed in samples of 8 first-ever lacunar stroke patients with MR imaging showing a single symptomatic lacunar lesion (type 1), and 8 with multiple additional "silent" lacunar lesions and extensive white matter lesions (type 2). A 16 kDa protein, identified as alpha-2-chain of haptoglobin (Hp), was found to be overrepresented in type 1 compared to type 2 (peak intensity 12.5 vs. 5.0; p=0.02). As a polymorphism with two alleles, Hp-1 and Hp 2, determines the presence of alpha-1 and/or alpha-2-chains in the Hp-molecule, Hp phenotypic analysis was performed. Hp 1 : Hp-2 allele frequency was 0.562 : 0.438 in type 1 and 0.812 : 0.188 in type 2 (population reference approximately 0.4 : 0.6). We conclude that the overrepresentation of the alpha-2-chain in lacunar stroke type 1 compared to type 2 relates to a higher Hp-2 allele frequency in the former. Yet, compared to population reference, the phenotype distribution in both patient groups deviates towards a high Hp-1 allele frequency. Our findings suggest a role for the Hp gene in the etiology of cerebral small vessel disease. Larger studies are now needed to explore this new candidate gene.