Predicting Early Mortality of Acute Ischemic Stroke.

Background and Purpose- Several risk factors are known to increase mid- and long-term mortality of ischemic stroke patients. Information on predictors of early stroke mortality is scarce but often requested in clinical practice. We therefore aimed to develop a rapidly applicable tool for predicting early mortality at the stroke unit. Methods- We used data from the nationwide Austrian Stroke Unit Registry and multivariate regularized logistic regression analysis to identify demographic and clinical variables associated with early (≤7 days poststroke) mortality of patients admitted with ischemic stroke. These variables were then used to develop the Predicting Early Mortality of Ischemic Stroke score that was validated both by bootstrapping and temporal validation. Results- In total, 77 653 ischemic stroke patients were included in the analysis (median age: 74 years, 47% women). The mortality rate at the stroke unit was 2% and median stay of deceased patients was 3 days. Age, stroke severity measured by the National Institutes of Health Stroke Scale, prestroke functional disability (modified Rankin Scale >0), preexisting heart disease, diabetes mellitus, posterior circulation stroke syndrome, and nonlacunar stroke cause were associated with mortality and served to build the Predicting Early Mortality of Ischemic Stroke score ranging from 0 to 12 points. The area under the curve of the score was 0.879 (95% CI, 0.871-0.886) in the derivation cohort and 0.884 (95% CI, 0.863-0.905) in the validation sample. Patients with a score ≥10 had a 35% (95% CI, 28%-43%) risk to die within the first days at the stroke unit. Conclusions- We developed a simple score to estimate early mortality of ischemic stroke patients treated at a stroke unit. This score could help clinicians in short-term prognostication for management decisions and counseling.

Blood Biomarkers of Heart Failure and Hypercoagulation to Identify Atrial Fibrillation-Related Stroke.

Background and Purpose- Occult atrial fibrillation (AF) causes a relevant proportion of initially cryptogenic stroke (CS), but prolonged rhythm monitoring is difficult to apply to all such patients. We hypothesized that blood biomarkers indicating heart failure (NT-proBNP [N-terminal pro-brain natriuretic peptide]) and hypercoagulability (D-dimer, AT-III [antithrombin-III]) were associated with AF-related stroke and could serve to predict the likelihood of AF detection in CS patients early on. Methods- Over a 1-year period, we prospectively applied a defined etiologic work-up to all ischemic stroke patients admitted to our stroke unit. If no clear stroke cause was detected (CS), patients underwent extended in-hospital cardiac rhythm monitoring (≥72 hours). Blood to determine biomarker levels was drawn within 24 hours after admission. Results- Of 429 patients, 103 had AF-related stroke. Compared with noncardiac stroke patients (n=171), they had higher NT-proBNP (1867 versus 263 pg/ml) and D-dimer levels (1.1 versus 0.6 µg/ml), and lower AT-III concentration (89% versus 94%). NT-proBNP ≥505 pg/ml distinguished AF-related from noncardiac stroke with a sensitivity of 93% and a specificity of 72%. D-dimer and AT-III cutoffs had lower sensitivities (61% and 53%) and specificities (58% and 69%) for AF-related stroke. Of all initially 143 CS patients, 14 were diagnosed with AF during in-hospital monitoring. The preidentified NT-proBNP cutoff ≥505 pg/ml correctly predicted AF in 12 of them (86%, negative predictive value: 98%), while D-dimer and AT-III cutoffs were noncontributory. Conclusions- This study supports the association of NT-proBNP and to a lesser extent of hypercoagulation markers with AF-related stroke. NT-proBNP seems helpful in selecting CS patients for immediate extended cardiac rhythm monitoring to detect occult AF whereby levels <505 pg/ml seem to have a high-negative predictive value.

Abnormal Blood Flow on Transcranial Duplex Sonography Predicts Poor Outcome After Stroke Thrombectomy.

Background and Purpose- Hemodynamic changes following mechanical thrombectomy for large vessel occlusion stroke could be associated with complications and might affect prognosis. We investigated postinterventional middle cerebral artery blood flow on transcranial duplex sonography (TCD) and its prognostic value for anterior large vessel occlusion stroke patients. Methods- We identified all ischemic stroke patients who had undergone mechanical thrombectomy for anterior circulation large vessel occlusion from 2010 onwards. Postinterventional middle cerebral artery flow was graded according to the sonographic Thrombolysis in Brain Ischemia score and related to patient outcome stratified by the angiographic Thrombolysis in Cerebral Infarction reperfusion status. Results- Of 215 large vessel occlusion stroke patients, 193 patients (90%) showed successful angiographic recanalization (Thrombolysis in Cerebral Infarction grade 2b-3). Of those, 69 (36%) patients had abnormal sonographic middle cerebral artery blood flow (Thrombolysis in Brain Ischemia grade 0-4) within 72 hours after mechanical thrombectomy, which was an independent predictor for poor 90-day outcome. Conclusions- TCD indicates abnormal middle cerebral artery hemodynamics in a substantial proportion of patients with angiographically defined successful mechanical thrombectomy of the anterior cerebral circulation. Such changes are associated with poor short-term outcome.

Post-reperfusion hyperperfusion after endovascular stroke treatment: a prospective comparative study of TCD versus MRI.

BACKGROUND: Increased middle cerebral artery (MCA) blood flow velocities on transcranial duplex sonography (TCD) were recently reported in individual patients after successful mechanical thrombectomy (MT) and were related to intracranial hemorrhage and poor outcome. However, the retrospective study design of prior studies precluded elucidation of the underlying pathomechanisms, and the relationship between TCD and brain parenchymal perfusion still remains to be determined. METHODS: We prospectively investigated consecutive patients with stroke successfully recanalized by MT with TCD and MRI including contrast-enhanced perfusion sequences within 48 hours post-intervention. Increased MCA flow on TCD was defined as >30% mean blood flow velocity in the treated MCA compared with the contralateral MCA. MRI blood flow maps served to assess hyperperfusion rated by neuroradiologists blinded to TCD. RESULTS: A total of 226 patients recanalized by MT underwent post-interventional TCD and 92 patients additionally had perfusion MRI. 85 patients (38%) had increased post-interventional MCA flow on TCD. Of these, 10 patients (12%) had an underlying focal stenosis. Increased TCD blood flow in the recanalized MCA was associated with larger infarct size, vasogenic edema, intracranial hemorrhage and poor 90-day outcome (all p≤0.005). In the subgroup for which both TCD and perfusion MRI were available, 29 patients (31%) had increased ipsilateral MCA flow velocities on TCD. Of these, 25 patients also showed parenchymal hyperperfusion on MRI (sensitivity 85%; specificity 62%). Hyperperfusion severity on MRI correlated with MCA flow velocities on TCD (rs=0.379, p<0.001). CONCLUSIONS: TCD is a reliable bedside tool to identify post-reperfusion hyperperfusion, correlates well with perfusion MRI, and indicates risk of reperfusion injury after MT.

Acute and Chronic Kidney Dysfunction and Outcome After Stroke Thrombectomy.

Data on the impact of kidney dysfunction on outcome in patients with stroke due to large vessel occlusion are scarce. The few available studies are limited by only considering single kidney parameters measured at one time point. We thus investigated the influence of both chronic kidney disease (CKD) and acute kidney injury (AKI) on outcome after mechanical thrombectomy. We included consecutive patients with anterior circulation large vessel occlusion stroke receiving mechanical thrombectomy at our center over an 8-year period. We extracted clinical data from a prospective registry and investigated kidney serum parameters at admission, the following day and throughout hospital stay. CKD and AKI were defined according to established nephrological criteria. Unfavorable outcome was defined as scores of 3-6 on the modified Rankin Scale 3 months post-stroke. Among 465 patients, 31.8% had an impaired estimated glomerular filtration rate (eGFR) at admission (< 60 ml/min/1.73 m2). Impaired admission eGFR was related to unfavorable outcome in univariable analysis (p = 0.003), but not after multivariable adjustment (p = 0.96). Patients frequently met AKI criteria at admission (24.5%), which was associated with unfavorable outcome in a multivariable model (OR 3.03, 95% CI 1.73-5.30, p < 0.001). Moreover, patients who developed AKI during hospital stay also had a worse outcome (p = 0.002 in multivariable analysis). While CKD was not associated with 3-month outcome, we identified AKI either at admission or throughout the hospital stay as an independent predictor of unfavorable prognosis in this study cohort. This finding warrants further investigation of kidney-brain crosstalk in the setting of acute stroke.

Non-invasive markers of liver fibrosis and outcome in large vessel occlusion stroke.

BACKGROUND: Liver fibrosis has been identified as an outcome predictor in cardiovascular disease and has been associated with hematoma expansion and mortality in patients with primary intracerebral hemorrhage. We aimed to explore whether clinically inapparent liver fibrosis is related to neurological outcome, mortality, and intracranial hemorrhage risk in ischemic stroke patients after mechanical thrombectomy. METHODS: We included consecutive patients with anterior circulation large vessel occlusion stroke treated at our center with mechanical thrombectomy between January 2011 and April 2019. Clinical data had been collected prospectively; laboratory data were extracted from our electronic hospital information system. We calculated the Fibrosis-4 index (FIB-4), an established non-invasive liver fibrosis test. The main outcomes were postinterventional intracranial hemorrhage, unfavorable functional status (modified Rankin scale scores of 3-6), and mortality three months post-stroke. RESULTS: In the 460 patients (mean age 69 years, 49.3% female) analyzed, FIB-4 indicated advanced liver fibrosis in 22.6%. Positive FIB-4 was associated with unfavorable neurological outcomes and mortality three months post-stroke, even after correction for co-factors [Odds Ratio (OR) 2.15 for unfavorable outcome in patients with positive FIB-4, 95% confidence interval (CI) 1.21-3.83, p = 0.009, and 2.16 for mortality, 95% CI 1.16-4.03, p = 0.01]. However, FIB-4 was neither related to hemorrhagic transformation nor symptomatic intracranial hemorrhage. Moreover, atrial fibrillation was more frequent in patients with liver fibrosis (p < 0.001). Two further commonly-used liver fibrosis indices (Forns index and the Easy Liver Fibrosis Test) yielded comparable results regarding outcome and atrial fibrillation. CONCLUSIONS: Clinically inapparent liver fibrosis (based on simple clinical and laboratory parameters) represents an independent risk factor for unfavorable outcomes, including mortality, at three months after stroke thrombectomy. Elevated liver fibrosis indices warrant further hepatological work-up and thorough screening for atrial fibrillation in stroke patients.

Early Progressive Changes in White Matter Integrity Are Associated with Stroke Recovery.

Information on microstructural white matter integrity has been shown to explain post-stroke recovery beyond clinical measures and focal brain damage. Especially, knowledge about early white matter changes might improve prediction of outcome. We investigated 42 acute reperfused ischemic stroke patients (mean age 66.5 years, 40% female, median admission NIHSS 9.5) with a symptomatic MRI-confirmed unilateral middle cerebral artery territory infarction 24-72 h post-stroke and after 3 months. All patients underwent neurological examination and brain MRI. Fifteen older healthy controls (mean age 57.3 years) were also scanned twice. We assessed fractional anisotropy (FA), mean diffusivity (MD), axial (AD), and radial diffusivity (RD). Patients showed significantly decreased white matter integrity in the hemisphere affected by the acute infarction 24-72 h post-stroke, which further decreased over 3 months compared with controls. Less decrease in FA of remote white matter tracts was associated with better stroke recovery even after correcting for infarct location and extent. A regression model including baseline information showed that the modified Rankin Scale and mean FA of the genu of the corpus callosum explained 53.5% of the variance of stroke recovery, without contribution of infarct volume. Furthermore, early dynamic FA changes of the corpus callosum within the first 3 months post-stroke independently predicted stroke recovery. Information from advanced MRI measures on white matter integrity at the acute stage, as well as early dynamic white matter degeneration beyond infarct location and extent, improve our understanding of post-stroke reorganization in the affected hemisphere and contribute to an improved prediction of recovery.

Increased middle cerebral artery mean blood flow velocity index after stroke thrombectomy indicates increased risk for intracranial hemorrhage.

BACKGROUND AND PURPOSE: Cerebral hyperperfusion has been related to the risk of intracranial hemorrhage (ICH) in stroke patients after vessel recanalization therapy. We hypothesized that after successful mechanical thrombectomy for acute anterior circulation stroke, hemodynamics detectable by transcranial Duplex (TCD) sonography would vary, and that increased blood flow velocities would be associated with ICH. METHODS: We retrospectively identified all ischemic stroke patients with successful endovascular recanalization for anterior circulation vessel occlusion (Thrombolysis in Cerebral Infarction 2b-3) between 2010 and 2017. We reviewed their postinterventional TCD examinations for mean blood flow (MBF) velocities of the recanalized and contralateral middle cerebral artery (MCA) and searched for an association with postinterventional ICH and clinical outcome. RESULTS: 123 stroke patients (mean age 63±14 years, 40% women) with successful anterior circulation thrombectomy were analyzed. Of those, 18 patients had postinterventional ICH. ICH patients had an increased MCA MBF velocity index (=MBF velocity of the recanalized divided by the contralateral MCA) compared with non-ICH patients (1.32±0.39 vs 1.02±0.32, P<0.001). In multivariate analysis, a higher MCA MBF velocity index was associated with postinterventional ICH and poor 90 day outcome. CONCLUSIONS: A high MCA MBF velocity index on TCD after successful recanalization therapy for anterior circulation stroke indicates a risk for postinterventional ICH and worse prognosis.

Lower levels of N-acetylaspartate in multiple sclerosis patients with the apolipoprotein E epsilon4 allele.

BACKGROUND: In multiple sclerosis (MS), the epsilon4 allele of apolipoprotein E (APOE epsilon4) has been associated with more rapid clinical worsening and more severe tissue damage on magnetic resonance imaging. OBJECTIVE: To use proton magnetic resonance spectroscopy ((1)H-MRS) to further explore the biochemical changes in the brains of patients with MS associated with APOE epsilon4. DESIGN: A 2-year clinical and (1)H-MRS follow-up cohort study. SETTING: The MS outpatient clinic, Department of Neurology, and Magnetic Resonance Center of Karl-Franzens University. PATIENTS: We performed (1)H-MRS of the central portion of both hemispheres and APOE genotyping in 72 patients (52 women and 20 men; mean +/- SD age, 34.8 +/- 8.8 years) with clinically definite relapsing-remitting MS. Repeated studies were performed in 44 patients after a mean +/- SD interval of 34 +/- 9 months. MAIN OUTCOME MEASURE: Levels of N-acetylaspartate as measured by (1)H-MRS. RESULTS: Patients with MS and an epsilon4 allele (n = 19) had a significantly lower mean +/- SD N-acetylaspartate-creatine ratio than those without an epsilon4 allele (n = 53) (1.73 +/- 0.26 vs 1.89 +/- 0.24; P =.04) despite the absence of significant differences in age at onset, disease duration, Expanded Disability Status Scale score, and number of previous relapses between subgroups. During follow-up, the drop in the N-acetylaspartate-creatine ratio of epsilon4 carriers was also significantly larger (-0.31 vs -0.10; P =.01). This was paralleled by a higher number of relapses (mean +/- SD, 4.1 +/- 2.7 vs 1.7 +/- 1.6; P =.02) and a faster although nonsignificant progression of disability (mean +/- SD (Delta)Expanded Disability Status Scale score, 0.9 +/- 1.8 vs 0.3 +/- 1.1; P =.19). CONCLUSIONS: The APOE epsilon4 allele has a negative effect on the course of MS, and increasing axonal damage may be an important mechanism.

Cerebrovascular complications and granuloma formation after wrapping or coating of intracranial aneurysms with cotton gauze and human fibrin adhesives: results from a single-center patient series over a 5-year period.

OBJECT: Reinforcement of intracranial aneurysms (IAs) by wrapping or coating is a well-established therapeutic approach to those IAs not amenable to any other definitive treatment, but has been associated with complications such as parent artery narrowing, granuloma formation, and ischemic stroke. The goal of this study was to systematically investigate cerebrovascular complications following this procedure. METHODS: The authors' hospital database was searched for all patients who underwent wrapping or coating of IAs with cotton gauze and human fibrin adhesives between October 2006 and October 2011. The follow-up records of these patients were extracted, including regular clinical visits and vascular imaging. RESULTS: Five hundred sixty-seven patients were treated for IAs over the 5-year period: 303 patients underwent endovascular strategies and 264 underwent craniotomies. Wrapping or coating of IAs was performed in 20 patients (3.5%). Parent artery narrowing occurred in 5 (25%) of the 20 patients and was associated with major ischemic strokes in 4 patients and severe headache in another. Ischemic strokes were associated with parent artery narrowing, which occurred early postoperatively in 2 patients or was a consequence of granuloma formation in 2 patients 1 and 2 months after the procedure, respectively. CONCLUSIONS: These data should add to the awareness of significant cerebrovascular complications following wrapping or coating of IAs with cotton gauze and human fibrin adhesives and indicate that major ischemic strokes need to be included in the risk/benefit considerations during decision making for such treatment strategies. Patients who receive IA wrapping should be monitored and followed up closely for arterial narrowing and granuloma formation.

Accelerated evolution of brain atrophy and "black holes" in MS patients with APOE-epsilon 4.

Apolipoprotein E (APOE)-epsilon4 has been associated with an unfavorable course of multiple sclerosis (MS). The mechanisms responsible for this are unclear, although cross-sectional MRI demonstrated a higher extent of "black holes" (BHs) in such patients. Here, we have studied the impact of the APOE genotype on both the longitudinal evolution of focal (BH ratio) and global (brain volume change [BVC]) brain tissue damage. Ninety-nine MS patients underwent ApoE genotyping, clinical examination, and magnetic resonance imaging at baseline and after 2.7 +/- 1.1 years to assess lesion load (LL) and BVC. In APOE-epsilon4 patients, the annual reduction in brain volume was fivefold higher (-0.65 +/- 0.61%) than in those without APOE-epsilon4 (-0.13 +/- 0.36%; p = 0.0001). At baseline, T(2) LL and T(1) LL were non-significantly higher in epsilon4 carriers, despite a shorter disease duration and absence of significant clinical differences. During follow-up, T(1) LL increased from 1.2 +/- 2.3 ccm to 1.7 +/- 2.7 ccm in the epsilon4 group, although T(2) LL did not change, leading to a significantly higher increase in the BH ratio [(T(1) LL/T(2) LL) x 100] from 5.5 to 12.4% (p = 0.005). BH ratio remained almost constant in non-epsilon4 patients (5.0 vs 5.7%). Accelerated brain tissue loss and a higher proportion of lesions evolving into BH therefore provide magnetic resonance imaging evidence for more pronounced tissue destruction in MS patients with APOE-epsilon4.