Julie Staals

A randomized trial of intraarterial treatment for acute ischemic stroke

BACKGROUND In patients with acute ischemic stroke caused by a proximal intracranial arterial occlusion, intraarterial treatment is highly effective for emergency revascularization. However, proof of a beneficial effect on functional outcome is lacking. METHODS We randomly assigned eligible patients to either intraarterial treatment plus usual care or usual care alone. Eligible patients had a proximal arterial occlusion in the anterior cerebral circulation that was confirmed on vessel imaging and that could be treated intraarterially within 6 hours after symptom onset. The primary outcome was the modified Rankin scale score at 90 days; this categorical scale measures functional outcome, with scores ranging from 0 (no symptoms) to 6 (death). The treatment effect was estimated with ordinal logistic regression as a common odds ratio, adjusted for prespecified prognostic factors. The adjusted common odds ratio measured the likelihood that intraarterial treatment would lead to lower modified Rankin scores, as compared with usual care alone (shift analysis). RESULTS We enrolled 500 patients at 16 medical centers in The Netherlands (233 assigned to intraarterial treatment and 267 to usual care alone). The mean age was 65 years (range, 23 to 96), and 445 patients (89.0%) were treated with intravenous alteplase before randomization. Retrievable stents were used in 190 of the 233 patients (81.5%) assigned to intraarterial treatment. The adjusted common odds ratio was 1.67 (95% confidence interval [CI], 1.21 to 2.30). There was an absolute difference of 13.5 percentage points (95% CI, 5.9 to 21.2) in the rate of functional independence (modified Rankin score, 0 to 2) in favor of the intervention (32.6% vs. 19.1%). There were no significant differences in mortality or the occurrence of symptomatic intracerebral hemorrhage. CONCLUSIONS In patients with acute ischemic stroke caused by a proximal intracranial occlusion of the anterior circulation, intraarterial treatment administered within 6 hours after stroke onset was effective and safe. (Funded by the Dutch Heart Foundation and others; MR CLEAN Netherlands Trial Registry number, NTR1804, and Current Controlled Trials number, ISRCTN10888758.).

Stroke subtype, vascular risk factors and total MRI brain small vessel disease burden

Objectives: In this cross-sectional study, we tested the construct validity of a “total SVD score,” which combines individual MRI features of small-vessel disease (SVD) in one measure, by testing associations with vascular risk factors and stroke subtype. Methods: We analyzed data from patients with lacunar or nondisabling cortical stroke from 2 prospective stroke studies. Brain MRI was rated for the presence of lacunes, white matter hyperintensities, cerebral microbleeds, and perivascular spaces independently. The presence of each SVD feature was summed in an ordinal “SVD score” (range 0–4). We tested associations with vascular risk factors, stroke subtype, and cerebral atrophy using ordinal regression analysis. Results: In 461 patients, multivariable analysis found that age (odds ratio [OR] 1.10, 95% confidence interval [CI] 1.08–1.12), male sex (OR 1.58, 95% CI 1.10–2.29), hypertension (OR 1.50, 95% CI 1.02–2.20), smoking (OR 2.81, 95% CI 1.59–3.63), and lacunar stroke subtype (OR 2.45, 95% CI 1.70–3.54) were significantly and independently associated with the total SVD score. The score was not associated with cerebral atrophy. Conclusions: The total SVD score may provide a more complete estimate of the full impact of SVD on the brain, in a simple and pragmatic way. It could have potential for patient or risk stratification or early efficacy assessment in clinical trials of interventions to prevent SVD progression and may (after further testing) have a useful role in clinical practice.

Virchow-Robin spaces relate to cerebral small vessel disease severity

Background and purposeVirchow-Robin spaces (VRs) are perivascular spaces surrounding the deep perforating brain arteries. VRs dilatation is pathologic, and it could be a manifestation of cerebral small vessel disease. In the present study we assessed the relation between VRs and silent ischemic lesions in a cohort of patients with cerebral small vessel disease.MethodsWe divided dilated VRs on MRI (1.5 Tesla) into three semi-quantitative categories in 165 first ever lacunar stroke patients. We counted asymptomatic lacunar infarcts and graded white matter lesions, and compared the prevalence of vascular risk factors in different categories of VRs. We also determined independent predictors of silent ischemic lesions.ResultsVRs at basal ganglia level related to age, hypertension, asymptomatic lacunar infarcts, and white matter lesions. VRs at basal ganglia level predicted silent ischemic lesions (odds ratio 10.58 per higher VRs category; 95 %- confidence interval 3.40 – 32.92).ConclusionDilated VRs in the basal ganglia relate to the severity of cerebral small vessel disease and might be a manifestation of the same small vessel abnormality that causes silent ischemic lesions. This adds a role for VRs as a potential marker for small vessel disease.

Time to Reperfusion and Treatment Effect for Acute Ischemic Stroke: A Randomized Clinical Trial

IMPORTANCE Intra-arterial treatment (IAT) for acute ischemic stroke caused by intracranial arterial occlusion leads to improved functional outcome in patients treated within 6 hours after onset. The influence of treatment delay on treatment effect is not yet known. OBJECTIVE To evaluate the influence of time from stroke onset to the start of treatment and from stroke onset to reperfusion on the effect of IAT. DESIGN, SETTING, AND PARTICIPANTS The Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN) was a multicenter, randomized clinical open-label trial of IAT vs no IAT in 500 patients. The time to the start of treatment was defined as the time from onset of symptoms to groin puncture (TOG). The time from onset of treatment to reperfusion (TOR) was defined as the time to reopening the vessel occlusion or the end of the procedure in cases for which reperfusion was not achieved. Data were collected from December 3, 2010, to June 3, 2014, and analyzed (intention to treat) from July 1, 2014, to September 19, 2015. MAIN OUTCOMES AND MEASURES Main outcome was the modified Rankin Scale (mRS) score for functional outcome (range, 0 [no symptoms] to 6 [death]). Multiple ordinal logistic regression analysis estimated the effect of treatment and tested for the interaction of time to randomization, TOG, and TOR with treatment. The effect of treatment as a risk difference on reaching independence (mRS score, 0-2) was computed as a function of TOG and TOR. Calculations were adjusted for age, National Institutes of Health Stroke Scale score, previous stroke, atrial fibrillation, diabetes mellitus, and intracranial arterial terminus occlusion. RESULTS Among 500 patients (58% male; median age, 67 years), the median TOG was 260 (interquartile range [IQR], 210-311) minutes; median TOR, 340 (IQR, 274-395) minutes. An interaction between TOR and treatment (P = .04) existed, but not between TOG and treatment (P = .26). The adjusted risk difference (95% CI) was 25.9% (8.3%-44.4%) when reperfusion was reached at 3 hours, 18.8% (6.6%-32.6%) at 4 hours, and 6.7% (0.4%-14.5%) at 6 hours. CONCLUSION AND RELEVANCE For every hour of reperfusion delay, the initially large benefit of IAT decreases; the absolute risk difference for a good outcome is reduced by 6% per hour of delay. Patients with acute ischemic stroke require immediate diagnostic workup and IAT in case of intracranial arterial vessel occlusion. TRIAL REGISTRATION trialregister.nl Identifier: NTR1804.

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.

Accumulation of MRI Markers of Cerebral Small Vessel Disease is Associated with Decreased Cognitive Function. A Study in First-Ever Lacunar Stroke and Hypertensive Patients

Background: White matter lesions (WMLs), asymptomatic lacunar infarcts, brain microbleeds (BMBs), and enlarged perivascular spaces (EPVS) have been identified as silent lesions due to cerebral small vessel disease (cSVD). All these markers have been individually linked to cognitive functioning, but are also strongly correlated with each other. The combined effect of these markers on cognitive function has never been studied and would possibly provide more useful information on the effect on cognitive function. Methods: Brain MRI and extensive neuropsychological assessment were performed in 189 patients at risk for cSVD (112 hypertensive patients and 77 first-ever lacunar stroke patients). We rated the presence of any asymptomatic lacunar infarct, extensive WMLs, any deep BMB, and moderate to extensive EPVS in the basal ganglia. The presence of each marker was summed to an ordinal score between 0 and 4. Associations with domains of cognitive function (memory, executive function, information processing speed, and overall cognition) were analyzed with correlation analyses. Results: Correlation analyses revealed significant associations between accumulating cSVD burden and decreased performance on all cognitive domains (all p ≤ 0.001). Results remained significant for information processing speed (r = −0.181, p = 0.013) and overall cognition (r = −0.178, p = 0.017), after correction for age and sex. Testing of trend using linear regression analyses revealed the same results. Discussion: We tested a new approach to capture total brain damage resulting from cSVD and found that accumulation of MRI burden of cSVD is associated with decreased performance on tests of information processing speed and overall cognition, implying that accumulating brain damage is accompanied by worse cognitive functioning.

Collateral Status on Baseline Computed Tomographic Angiography and Intra-Arterial Treatment Effect in Patients with Proximal Anterior Circulation Stroke

Background and Purpose— Recent randomized trials have proven the benefit of intra-arterial treatment (IAT) with retrievable stents in acute ischemic stroke. Patients with poor or absent collaterals (preexistent anastomoses to maintain blood flow in case of a primary vessel occlusion) may gain less clinical benefit from IAT. In this post hoc analysis, we aimed to assess whether the effect of IAT was modified by collateral status on baseline computed tomographic angiography in the Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN). Methods— MR CLEAN was a multicenter, randomized trial of IAT versus no IAT. Primary outcome was the modified Rankin Scale at 90 days. The primary effect parameter was the adjusted common odds ratio for a shift in direction of a better outcome on the modified Rankin Scale. Collaterals were graded from 0 (absent) to 3 (good). We used multivariable ordinal logistic regression analysis with interaction terms to estimate treatment effect modification by collateral status. Results— We found a significant modification of treatment effect by collaterals (P=0.038). The strongest benefit (adjusted common odds ratio 3.2 [95% confidence intervals 1.7–6.2]) was found in patients with good collaterals (grade 3). The adjusted common odds ratio was 1.6 [95% confidence intervals 1.0–2.7] for moderate collaterals (grade 2), 1.2 [95% confidence intervals 0.7–2.3] for poor collaterals (grade 1), and 1.0 [95% confidence intervals 0.1–8.7] for patients with absent collaterals (grade 0). Conclusions— In MR CLEAN, baseline computed tomographic angiography collateral status modified the treatment effect. The benefit of IAT was greatest in patients with good collaterals on baseline computed tomographic angiography. Treatment benefit appeared less and may be absent in patients with absent or poor collaterals. Clinical Trial Registration— URL: http://www.trialregister.nl and http://www.controlled-trials.com. Unique identifier: (NTR)1804 and ISRCTN10888758, respectively.

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.

Total MRI load of cerebral small vessel disease and cognitive ability in older people

Cerebral small vessel disease (SVD) may cause cognitive dysfunction. We tested the association between the combined presence of magnetic resonance imaging (MRI) features of SVD and cognitive ability in older age. Cognitive testing and brain MRI were performed in 680 older participants. MRI presence of lacunes, white matter hyperintensities, microbleeds, and perivascular spaces were summed in a score of 0–4 representing all SVD features combined. We also applied latent variable modeling to test whether the 4 MRI features form a unitary SVD construct. The SVD score showed significant associations with general cognitive ability. Latent variable modeling indicated that the 4 MRI markers formed a unitary construct, which showed consistent associations with cognitive ability compared with the SVD score. Total MRI load of SVD is associated with lower general cognitive ability in older age. The total SVD score performed consistently with the more complex latent variable model, suggesting validity and potential utility in future research for determining total SVD load.

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.