Validation of an acute ischemic stroke model: does diffusion-weighted imaging lesion volume offer a clinically significant improvement in prediction of outcome?

Cytoprotective protein C pathways and implications for stroke and neurological disorders

Recent studies indicate that single-action-single-target agents are unlikely to cure CNS disorders sharing a pathogenic triad consisting of vascular damage, neuronal injury/neurodegeneration and neuroinflammation. Here we focus on a recent example of a multiple-action-multiple-target approach for CNS disorders based on newly discovered biological properties of activated protein C (APC), an endogenous plasma protease with antithrombotic, cytoprotective and anti-inflammatory activities in the CNS. We propose that APC-mediated signaling through the protease activated receptor-1 (PAR1) can favorably regulate multiple pathways within the neurovascular unit in non-neuronal cells and neurons during acute or chronic CNS insults, leading to stabilization of the blood-brain barrier (BBB), neuroprotection and control of neuroinflammation. Although much remains to be understood regarding the biology of APC, preclinical studies suggest that APC has promising applications as disease-modifying therapy for ischemic stroke and other neuropathologies whose underlying pathology involves deficits in the vasculo-neuronal-inflammatory triad.

A 5-Item Scale to Predict Stroke Outcome After Cortical Middle Cerebral Artery Territory Infarction

Background and Purpose—

Various clinical, laboratory, and radiographic parameters have been identified as predictors of outcome for ischemic stroke. The purpose of this study was to combine these parameters into a validated scale for outcome prognostication in patients with a middle cerebral artery territory infarction.

Methods—

We retrospectively reviewed 129 patients over a 2-year period and considered demographic, clinical, laboratory, and radiographic parameters as potential predictors of outcome. Inclusion criteria were unilateral hemispheric infarcts within the middle cerebral artery territory >15 mm in diameter. Our primary outcome measure was a favorable recovery defined as a modified Rankin Score was ≤2 at 30 days. A multivariable model was used to determine independent predictors of outcome and weighted to create a 5-item scale to predict stroke recovery. External validation of this model was done using data from the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution (DEFUSE) study.

Results—

The 5 independent predictors of outcome were as follows: age (OR, 1.09; 95% CI, 1.03 to 1.14; P =0.001), National Institutes of Health Stroke Scale score (OR, 1.17; 95% CI, 1.06 to 1.30; P =0.003), infarct volume (OR, 1.01; 95% CI, 1.00 to 1.02; P =0.03), admission white blood cell count (8.5×10 3 /mm 3 ; OR, 1.16; 95% CI, 1.03 to 1.27; P =0.04), and presence of hyperglycemia (OR, 4.2; 95% CI, 1.1 to 16.4; P =0.04). Combining these variables into a point scale significantly improved prediction over the individual variables accounted alone as evidenced by the area underneath the receiver operating curve (OR, 0.91; 95% CI, 0.87 to 0.96; P =0.0001). When applied to the DEFUSE study population for validation, the model achieved a sensitivity of 83% and specificity of 86%.

Conclusions—

With validation from a prospective study of similar patients, this model serves as a useful clinical and research tool to predict stroke recovery after cortical middle cerebral artery territory infarction.

DWI Reversibility after Intra-Arterial Thrombolysis. A Case Report and Literature Review

We report our case and review the literature on reversal DWI lesions, ADC thresholds and correlation between DWI lesion and outcome measured with clinical scales. A 30-years old woman was admitted to our hospital 18 hours after stroke onset. Considering the absence of alterations on CT and the worsening of symptomatology, the patient underwent MRI, which showed a slightly hyperintense signal in FLAIR images in the left portion of the pons and midbrain and a more evident bilateral DWI hyperintensity of the pons. The patient was treated with mechanical and pharmacological intra-arterial thrombolysis. The patient showed a rapid improvement of symptoms. Two weeks after the treatment her clinical conditions were characterized by a residual right hemiparesis and complete recovery of right motility, respiratory and swallowing difficulties. MR examination demonstrated a slight signal alteration of the pons left hemiportion and a disappearance of the mesencephalic signal alteration and of the right portion of the pons. DWI lesions represent irreversibly damaged tissue but new evidence suggests that DWI lesions may be reversible, especially with reperfusion, by now well demonstrated in animal models. Therefore acute DWI lesions probably contain not only irreversibly injured tissue but also parts of the penumbra. The debate on the capability of ADC maps to discriminate irreversibly from reversibly damaged tissue is a matter of controversy. ADC values in human stoke are not an independent indicator of tissue viability. The use of thresholds may improve reproducibility but not validity.

Can molecular and cellular neuroprotection be translated into therapies for patients?: yes, but not the way we tried it before

BACKGROUND AND PURPOSE

The concept of neuroprotection is based on sound scientific data derived in preclinical studies. However, candidate neuroprotectants have never been successfully translated to patients.

METHODS

A review of past approaches to cellular and molecular neuroprotection, preclinical neuroprotection studies, and clinical approaches was undertaken.

RESULTS

Although there is no evidence for fundamental barriers in biological principles that limit the translation of promising therapies to humans, ample evidence exists as to a lack of rigor in preclinical studies, obstacles posed by the complexities of acute ischemic stroke syndromes, and regulatory barriers. Alternative methods to translating stroke drugs may require trials in restricted stroke indications in well-defined patient populations.

CONCLUSIONS

The translational gap between cellular and molecular neuroscience and patient therapy may be bridged by first developing therapies for narrow stroke indications. A single success may stimulate further research, funding, and a capacity to generalize initial results to broader stroke populations.

Risk Score for In-Hospital Ischemic Stroke Mortality Derived and Validated Within the Get With The Guidelines–Stroke Program

Background—

There are few validated models for prediction of in-hospital mortality after ischemic stroke. We used Get With the Guidelines–Stroke Program data to derive and validate prediction models for a patient's risk of in-hospital ischemic stroke mortality.

Methods and Results—

Between October 2001 and December 2007, there were 1036 hospitals that contributed 274 988 ischemic stroke patients to this study. The sample was randomly divided into a derivation (60%) and validation (40%) sample. Logistic regression was used to determine the independent predictors of mortality and to assign point scores for a prediction model. We also separately derived and validated a model in the 109 187 patients (39.7%) with a National Institutes of Health Stroke Scale (NIHSS) score recorded. Model discrimination was quantified by calculating the C statistic from the validation sample. In-hospital mortality was 5.5% overall and 5.2% in the subset in which NIHSS score was recorded. Characteristics associated with in-hospital mortality were age, arrival mode (eg, via ambulance versus other mode), history of atrial fibrillation, previous stroke, previous myocardial infarction, carotid stenosis, diabetes mellitus, peripheral vascular disease, hypertension, history of dyslipidemia, current smoking, and weekend or night admission. The C statistic was 0.72 in the overall validation sample and 0.85 in the model that included NIHSS score. A model with NIHSS score alone provided nearly as good discrimination (C statistic 0.83). Plots of observed versus predicted mortality showed excellent model calibration in the validation sample.

Conclusions—

The Get With the Guidelines–Stroke risk model provides clinicians with a well-validated, practical bedside tool for mortality risk stratification. The NIHSS score provides substantial incremental information on a patient's short-term mortality risk and is the strongest predictor of mortality.

DW-MRI of the urogenital tract: applications in oncology

Diffusion-weighted magnetic resonance imaging (DW-MRI) appears to hold promise as a non-invasive imaging modality in the detection of early microstructural and functional changes of different organs. DW-MRI is an imaging technique with a high sensitivity for the detection of a large variety of diseases in the urogenital tract. In kidneys, DW-MRI has shown promise for the characterization of solid lesions. Also in focal T1 hyperintense lesions DW-MRI was able to differentiate hemorrhagic cysts from tumours according to the lower apparent diffusion coefficient (ADC) values reported for renal cell carcinomas. Promising results were also published for the detection of prostate cancer. DW-MRI applied in addition to conventional T2-weighted imaging has been found to improve tumour detection. On a 3 T magnetic resonance unit ADC values were reported to be lower for tumours compared with the normal-appearing peripheral zone. The combined approach of T2-weighted imaging and DW-MRI also showed promising results for the detection of recurrent tumour in patients after radiation therapy. DW-MRI may improve the performance of conventional T2-weighted and contrast-enhanced MRI in the preoperative work-up of bladder cancer, as it may help in distinguishing superficial from muscle invasive bladder cancer, which is critical for patient management. Another challenging application of DW-MRI in the urogenital tract is the detection of pelvic lymph node metastases. As the ADC is generally reduced in malignant tumours and increased under inflammatory conditions, reduced ADC values were expected in patients with lymph node metastases.

Predictors of percutaneous endoscopic gastrostomy tube placement in patients with severe dysphagia from an acute-subacute hemispheric infarction

This study investigated the influence of age, National Institutes of Health Stroke Scale (NIHSS) score, time from stroke onset, infarct location and volume in predicting placement of a percutaneous endoscopic gastrostomy (PEG) tube in patients with severe dysphagia from an acute-subacute hemispheric infarction. We performed a retrospective analysis of a hospital-based patient cohort to analyze the effect of the aforementioned variables on the decision of whether or not to place a PEG tube. Consecutive patients were identified using International Classification of Diseases, Ninth Revision (ICD-9) codes for acute ischemic stroke, Current Procedural Terminology (CPT)-4 codes for a formal swallowing evaluation by a speech pathologist, and procedure codes for PEG placement over a 5-year period from existing medical records at our institution. Only patients with severe dysphagia were enrolled. A total of 77 patients met inclusion criteria; 20 of them underwent PEG placement. The relationship between age (dichotomized; < and ≥75 years), time from stroke onset (days), NIHSS score, acute infarct lesion volume (dichotomized; < and ≥100 cc), and infarct location (ie, insula, anterior insula, periventricular white matter, inferior frontal gyrus, motor cortex, or bilateral hemispheres) with PEG tube placement were analyzed using logistic regression analysis. In univariate analysis, NIHSS score (P = .005), lesion volume (P = .022), and presence of bihemispheric infarction (P = .005) were found to be the main predictors of interest. After multivariate adjustment, only NIHSS score (odds ratio [OR], 1.15; 90% confidence interval [CI], 1.02-1.29; P = .04) and presence of bihemispheric infarcts (OR, 4.67; 90% CI, 1.58-13.75; P = .018) remained significant. Our data indicates that baseline NIHSS score and the presence of bihemispheric infarcts predict PEG placement during hospitalization from an acute-subacute hemispheric infarction in patients with severe dysphagia. These results require further validation in future studies.

Predicting functional outcome after stroke by modelling baseline clinical and CT variables

BACKGROUND

we aimed to assess whether the performance of stroke outcome models comprising simple clinical variables could be improved by the addition of more complex clinical variables and information from the first computed tomography (CT) scan.

METHODS

538 consecutive acute ischaemic and haemorrhagic stroke patients were enrolled in a Stroke Outcome Study between 2001 and 2002. Independent survival (modified Rankin scale <or=2) was assessed at 6 months. Models based on clinical and radiological variables from the first assessment were developed using multivariate logistic regression analysis.

RESULTS

three models were developed (I-III). Model I included age, pre-stroke independence, arm power and a stroke severity score (area under a receiver operating characteristic curve, AUC = 0.882) but performed no better than Model II, which comprised age, pre-stroke independence, normal verbal component of the Glasgow coma score, arm power and being able to walk without assistance (AUC 0.876). Model III, including two radiological variables and clinical variables, was not statistically superior to model II (AUC 0.901, P = 0.12). Model II was externally validated in two independent datasets (AUCs of 0.773 and 0.787).

CONCLUSION

this study demonstrates an externally validated stroke outcome prediction model using simple clinical variables. Outcome prediction was not significantly improved with CT-derived radiological variables or more complex clinical variables.

Acute corticospinal tract Wallerian degeneration is associated with stroke outcome

BACKGROUND AND PURPOSE

In children with stroke, poor motor outcome is associated with early Wallerian degeneration of the corticospinal tract that is seen on diffusion-weighted MRI. In this study we test the hypothesis that early diffusion changes also occur in the corticospinal tract (CST) of adults after stroke and that these lesions are associated with poor outcome.

METHODS

In this retrospective study, we assessed images from a serial MRI study of adults with acute middle cerebral/internal carotid artery stroke. MRI-negative TIA patients served as controls. Custom software measured signal along the CST on different sequences, including the apparent diffusion coefficient (ADC). Visual detection of abnormal signal by blinded neuroradiologists was also evaluated. We then determined associations between CST signal changes and 3-month motor outcome (NIHSS score).

RESULTS

Thirty-eight patients (20 stroke/18 control) were included. ADC measures were much more accurate than other MRI sequences for detection of degeneration in the CST. The ADC decreased in a time-dependent fashion in the CST of patients with poor motor outcome but not in those with good outcome. Changes in ADC were maximal at 7 days. Neuroradiologists could visually detect these changes with accuracy comparable to the software method.

CONCLUSION

CST ADC decreases after acute stroke in patients with poor motor outcome and may represent early Wallerian degeneration. Recognition of this imaging marker may improve early outcome prediction and patient selection for rehabilitation and neuroprotection trials.

Glucose Regulation in Acute Stroke Patients (GRASP) trial: a randomized pilot trial

BACKGROUND AND PURPOSE

Hyperglycemia is associated with worse outcome in patients with acute stroke.

METHODS

We conducted a prospective, randomized, multicenter, 3-arm trial (tight control [target 70 to 110 mg/dL], loose control [target 70 to 200 mg/dL], and control usual care [70 to 300 mg/dL]) to assess the feasibility and safety of 2 insulin infusion protocol targets in patients with acute ischemic stroke. The planned sample was 72 subjects.

RESULTS

A total of 74 subjects were enrolled. Seventy-two (97%) had data available for the primary analyses and 73 (99%) had 3-month clinical outcome data. Median age was 67 years, median National Institutes of Health Stroke Scale score was 8, median glucose was 163 mg/dL, and median time to randomization was 10.7 hours. Fifty-nine percent of patients were diabetic, 35% received thrombolysis, and 14% of subjects died within 3 months. The loose control and usual care groups had median glucose concentrations of 151 mg/dL. The tight control group had a median glucose concentration of 111 mg/dL. The loose control group spent 90% of the first 24 hours in target and the tight group 44% of time in target. There was only one symptomatic patient with hypoglycemia in the loose control group (4%) and zero in the tight control group. The overall rates of hypoglycemia (<55 mg/dL) were 4% in control, 4% in loose, and 30% in tight. Exploratory efficacy analysis was conducted.

CONCLUSIONS

Insulin infusion for patients with acute ischemic stroke is feasible and safe using the insulin infusion protocol in the Glucose Regulation in Acute Stroke Patients (GRASP) trial. Exploratory efficacy analysis supports further comparative study.

Recombinant human erythropoietin in the treatment of acute ischemic stroke

BACKGROUND AND PURPOSE

Numerous preclinical findings and a clinical pilot study suggest that recombinant human erythropoietin (EPO) provides neuroprotection that may be beneficial for the treatment of patients with ischemic stroke. Although EPO has been considered to be a safe and well-tolerated drug over 2 decades, recent studies have identified increased thromboembolic complications and/or mortality risks on EPO administration to patients with cancer or chronic kidney disease. Accordingly, the double-blind, placebo-controlled, randomized German Multicenter EPO Stroke Trial (Phase II/III; ClinicalTrials.gov Identifier: NCT00604630) was designed to evaluate efficacy and safety of EPO in stroke.

METHODS

This clinical trial enrolled 522 patients with acute ischemic stroke in the middle cerebral artery territory (intent-to-treat population) with 460 patients treated as planned (per-protocol population). Within 6 hours of symptom onset, at 24 and 48 hours, EPO was infused intravenously (40,000 IU each). Systemic thrombolysis with recombinant tissue plasminogen activator was allowed and stratified for.

RESULTS

Unexpectedly, a very high number of patients received recombinant tissue plasminogen activator (63.4%). On analysis of total intent-to-treat and per-protocol populations, neither primary outcome Barthel Index on Day 90 (P=0.45) nor any of the other outcome parameters showed favorable effects of EPO. There was an overall death rate of 16.4% (n=42 of 256) in the EPO and 9.0% (n=24 of 266) in the placebo group (OR, 1.98; 95% CI, 1.16 to 3.38; P=0.01) without any particular mechanism of death unexpected after stroke.

CONCLUSIONS

Based on analysis of total intent-to-treat and per-protocol populations only, this is a negative trial that also raises safety concerns, particularly in patients receiving systemic thrombolysis.

Stroke Therapy Academic Industry Roundtable (STAIR) recommendations for extended window acute stroke therapy trials

The Stroke Therapy Academic Industry Roundtable (STAIR) meetings focus on helping to advance the development of acute stroke therapies. Further extending the time window for acute stroke therapies is an important endeavor for increasing the number of stroke patients who might benefit from treatment. The STAIR group recommends that future extended time window trials initially should focus on selected patient groups most likely to respond to investigational therapies and that penumbral imaging is one tool that may identify such patients. The control group in these trials should receive best locally available medical care; if regulatory approval for intravenous (i.v.) tPA is extended to 4.5 hours, then tPA will become the most appropriate comparator in trials conducted within this time window. In future well-designed extended window clinical trials randomization is appropriate and should not be precluded by using unproven treatment with intraarterial (i.a.) thrombolysis or mechanical devices. For proof of concept, extended time window, phase II trials of i.v. thrombolysis, or mechanical devices in which early recanalization/reperfusion is the primary end point, rescue therapy/bailout treatment with i.a. thrombolysis or devices may be acceptable. Statistical considerations and definitions of successful recanalization/reperfusion are suggested for these trials.

Diffusion-weighted magnetic resonance imaging as a cancer biomarker: consensus and recommendations

On May 3, 2008, a National Cancer Institute (NCI)-sponsored open consensus conference was held in Toronto, Ontario, Canada, during the 2008 International Society for Magnetic Resonance in Medicine Meeting. Approximately 100 experts and stakeholders summarized the current understanding of diffusion-weighted magnetic resonance imaging (DW-MRI) and reached consensus on the use of DW-MRI as a cancer imaging biomarker. DW-MRI should be tested as an imaging biomarker in the context of well-defined clinical trials, by adding DW-MRI to existing NCI-sponsored trials, particularly those with tissue sampling or survival indicators. Where possible, DW-MRI measurements should be compared with histologic indices including cellularity and tissue response. There is a need for tissue equivalent diffusivity phantoms; meanwhile, simple fluid-filled phantoms should be used. Monoexponential assessments of apparent diffusion coefficient values should use two b values (>100 and between 500 and 1000 mm2/sec depending on the application). Free breathing with multiple acquisitions is superior to complex gating techniques. Baseline patient reproducibility studies should be part of study designs. Both region of interest and histogram analysis of apparent diffusion coefficient measurements should be obtained. Standards for measurement, analysis, and display are needed. Annotated data from validation studies (along with outcome measures) should be made publicly available. Magnetic resonance imaging vendors should be engaged in this process. The NCI should establish a task force of experts (physicists, radiologists, and oncologists) to plan, organize technical aspects, and conduct pilot trials. The American College of Radiology Imaging Network infrastructure may be suitable for these purposes. There is an extraordinary opportunity for DW-MRI to evolve into a clinically valuable imaging tool, potentially important for drug development.

Change in diffusion-weighted imaging infarct volume predicts neurologic outcome at 90 days: results of the Acute Stroke Accurate Prediction (ASAP) trial serial imaging substudy

BACKGROUND AND PURPOSE

Predictive models of outcome after ischemic stroke have incorporated acute diffusion-weighted MRI (DWI) information with mixed results. We hypothesized that serial measurements of DWI infarct volume would be predictive of functional outcome after ischemic stroke.

METHODS

The prospective Acute Stroke Accurate Prediction (ASAP) Study included a prespecified serial imaging subgroup who underwent DWI studies at baseline (<24 hours after symptom onset) and Day 5 (+/-2 days). DWI infarct volumes were calculated using the Analyze software (Rochester, Minn). Clinical outcomes were assessed at 3 months. Univariate and multivariable regression analysis was performed to assess the relationship between change in DWI lesion volume and excellent neurological outcome (modified Rankin Scale 0, 1, and Barthel Index >or=95).

RESULTS

In total, 169 cases from the ASAP study had serial DWI scans with a measurable lesion at baseline, follow-up, or both. The median baseline National Institutes of Health Stroke Scale score was 6 (interquartile range, 3 to 13). For each 10 cm(3) of growth in DWI infarct volume, the OR for achieving an excellent outcome by modified Rankin Scale was 0.52 (95% CI, 0.38 to 0.71) and for the Barthel Index was 0.64 (95% CI, 0.51 to 0.79). Adjusting for clinically important covariates, the OR for an excellent modified Rankin Scale outcome was 0.57 (95% CI, 0.37 to 0.88) and excellent Barthel Index outcome was 0.75 (95% CI, 0.56 to 1.01).

CONCLUSIONS

Based on these data, the likelihood of achieving an excellent neurological outcome diminishes substantially with growth in DWI infarct volume in the first 5 days after ischemic stroke of mild to moderate severity.

A 12-year prospective study of stroke risk in older Medicare beneficiaries

BACKGROUND

5.8 M living Americans have experienced a stroke at some time in their lives, 780K had either their first or a recurrent stroke this year, and 150K died from strokes this year. Stroke costs about $66B annually in the US, and also results in serious, long-term disability. Therefore, it is prudent to identify all possible risk factors and their effects so that appropriate intervention points may be targeted.

METHODS

Baseline (1993-1994) interview data from the nationally representative Survey on Assets and Health Dynamics among the Oldest Old (AHEAD) were linked to 1993-2005 Medicare claims. Participants were 5,511 self-respondents >or= 70 years old. Two ICD9-CM case-identification approaches were used. Two approaches to stroke case-identification based on ICD9-CM codes were used, one emphasized sensitivity and the other emphasized specificity. Participants were censored at death or enrollment into managed Medicare. Baseline risk factors included sociodemographic, socioeconomic, place of residence, health behavior, disease history, and functional and cognitive status measures. A time-dependent marker reflecting post-baseline non-stroke hospitalizations was included to reflect health shocks, and sensitivity analyses were conducted to identify its peak effect. Competing risk, proportional hazards regression was used.

RESULTS

Post-baseline strokes occurred for 545 (9.9%; high sensitivity approach) and 374 (6.8%; high specificity approach) participants. The greatest static risks involved increased age, being widowed or never married, living in multi-story buildings, reporting a baseline history of diabetes, hypertension, or stroke, and reporting difficulty picking up a dime, refusing to answer the delayed word recall test, or having poor cognition. Risks were similar for both case-identification approaches and for recurrent and first-ever vs. only first-ever strokes. The time-dependent health shock (recent hospitalization) marker did not alter the static model effect estimates, but increased stroke risk by 200% or more.

CONCLUSION

The effect of our health shock marker (a time-dependent recent hospitalization indicator) was large and did not mediate the effects of the traditional risk factors. This suggests an especially vulnerable post-hospital transition period from adverse effects associated with both their underlying health shock (the reasons for the recent hospital admission) and the consequences of their treatments.

Clinical determinants of infarct pattern subtypes in large vessel atherosclerotic stroke

BACKGROUND

Although stroke from large vessel atherothromboembolism has a common pathogenesis, its topographic presentation is variable. Given the impact of cerebral infarct size and location on incident stroke magnitude and subsequent prognosis, we evaluated the determinants of cerebral infarct topography among patients with atherosclerotic stroke.

METHODS

We analyzed data on 148 consecutive patients admitted over a 4-year period to a university medical center with acute ischemic stroke within the MCA distribution on DWI, presumed due to atherosclerosis. Based on the DWI data, we divided the patients into three stroke phenotypes: large cortical, small (< 1 cm in diameter) cortical, and deep pattern. Independent factors for each stroke phenotype were evaluated using logistic regression.

RESULTS

After adjusting for covariates, premorbid statin use (OR, 3.05; 95% CI, 1.40-6.65) and older age (OR, 1.05 per 1 year increase; 95% CI, 1.02-1.08) were independently associated with the small cortical phenotypic pattern. In contrast, younger age (OR, 0.95 per 1 year increase; 95% CI, 0.92-0.98), premorbid statin non-use (OR, 0.40; 95% CI, 0.17-0.99), and higher levels of fasting s-glucose (OR, 1.01 per 1 mg/dl increase; 95% CI, 1.00-1.02) and admission peripheral WBC counts (OR, 1.13 per 1 x 10(9) cells/L; 95% CI, 1.00-1.27) were independently associated with the large cortical pattern. There was no relation between DWI patterns and LDL-cholesterol levels.

CONCLUSIONS

Age, premorbid statin use, s-glucose and WBC count predict atherosclerotic stroke phenotype. Further studies should examine whether modifying some of these factors may result in more favorable phenotypic patterns.

[Ischemic stroke in the elderly--analysis of the Austrian Stroke Unit Registry]

Epidemiological and benchmarking parameters of patients with ischemic stroke were collected in the Austrian Stroke Unit Registry from January 2003 till February 2007. 13,440 patient-data were analysed. 9509 were under 80 years old, 3931 were older than 80. Old patients showed worse clinical symptoms upon admission (NIHSS 9 vs. 6) and doubled mortality by worse pre-morbid status (mRS 1.27 vs. 0.47) in comparison to younger ones. Numerous other parameters were tested and compared in both groups of patients.

Predicting recovery after intracerebral hemorrhage--an external validation in patients from controlled clinical trials

BACKGROUND

An early and reliable prognostic indication in stroke patients is potentially useful for initiation of individual treatment and for informing patients and relatives. We recently developed a regression model as well as a simple 11-point predictive score (Essen ICH score) for functional recovery within three months after acute intracerebral hemorrhage (ICH) based on age and the National Institutes of Health Stroke Scale (NIH-SS). Here, we demonstrate the applicability of our models in an independent sample of ICH patients from controlled clinical trials.

METHODS

The prognostic models were used to predict functional recovery in 564 patients from the Virtual International Stroke Trials Archive (VISTA). Furthermore, we tried to improve the accuracy by re-calibration and estimating new model parameters.

FINDINGS

The logistic regression model and the Essen ICH score were able to correctly classify 77.5 % and 76.4 % of patients, respectively. Re-calibration and novel estimation of parameters yielded only a slight improvement of overall predictive accuracy.

INTERPRETATION

For acute ICH patients included in controlled trials, our predictive models based on age and the NIH-SS correctly predict functional recovery after three months and could be useful for future trial design.

Clinical and imaging data at 5 days as a surrogate for 90-day outcome in ischemic stroke

BACKGROUND AND PURPOSE

A simple, easily measured surrogate outcome measure for use in early treatment trials for acute ischemic stroke therapies would be highly valued. We hypothesized that day-5 NIH stroke scale score (NIHSS) and day-5 diffusion weighted imaging (DWI) volume would predict clinical outcome better than either alone and could be considered as a possible surrogate outcome in early phase acute stroke trials.

METHODS

The prospective Acute Stroke Accurate Prediction (ASAP) trial included a prespecified subgroup evaluated for early outcome. Logistic regression analysis was used to assess the prediction of modified Rankin (mRankin) of 0 or 1.

RESULTS

A total of 204 subjects completed the substudy, and 116 (57%) had excellent outcome at 3 months. The area under the ROC curve (AUC) for day-5 NIHSS predicting 3-month excellent outcome was 0.84; for DWI volume predicting outcome was 0.76, and for the multivariable model combining both was 0.84.

CONCLUSIONS

The results of the early outcome substudy of the ASAP trial suggest that early stroke severity and infarct volume measures are predictive of 3-month excellent outcome. In our data set the DWI volume does not add clinically relevant information in predicting 3-month outcome. Validation of these results is required.

The MRA-DWI mismatch identifies patients with stroke who are likely to benefit from reperfusion

BACKGROUND AND PURPOSE

The aim of this exploratory analysis was to evaluate if a combination of MR angiography (MRA) and diffusion-weighted imaging (DWI) selection criteria can be used to identify patients with acute stroke who are likely to benefit from early reperfusion.

METHODS

Data from DEFUSE, a study of 74 patients with stroke who received intravenous tissue plasminogen activator in the 3- to 6-hour time window and underwent MRIs before and approximately 4 hours after treatment were analyzed. The MRA-DWI mismatch model was defined as (1) a DWI lesion volume less than 25 mL in patients with a proximal vessel occlusion; or (2) a DWI lesion volume less than 15 mL in patients with proximal vessel stenosis or an abnormal finding of a distal vessel. Favorable clinical response was defined as an improvement on the National Institutes of Health Stroke Scale score of at least 8 points between baseline and 30 days or a National Institutes of Health Stroke Scale score </=1 at 30 days.

RESULTS

Twenty-seven of 62 patients (44%) had an MRA-DWI mismatch. There was a differential response to early reperfusion based on MRA-DWI mismatch status. Reperfusion was associated with an increased rate of a favorable clinical response in patients with an MRA-DWI mismatch (OR, 12.5; 95% CI, 1.8 to 83.9) and a lower rate in patients without mismatch (OR, 0.2; 95% CI, 0.0 to 0.8).

CONCLUSIONS

The MRA-DWI mismatch model appears to identify patients with stroke who are likely to benefit from reperfusion therapy administered in the 3- to 6-hour time window after symptom onset. The criteria established for the MRA-DWI mismatch model in this study require validation in an independent cohort.

Association of endovascular therapy of very small ruptured aneurysms with higher rates of procedure-related rupture

OBJECT

Procedure-related rupture during endovascular therapy of intracranial aneurysms is associated with a mortality rate of more than one third. Previously ruptured aneurysms are a known risk factor for procedure-related rupture. The objective of this study was to evaluate whether very small, ruptured aneurysms are associated with more frequent intraprocedural ruptures.

METHODS

This was a retrospective cohort study in which the investigators examined consecutive ruptured aneurysms treated with coil embolization at a single institution. The study was approved by the institutional review board. Very small aneurysms were defined as < or = 3 mm. Procedure-related rupture was defined as contrast extravasation during treatment. Univariate analysis with the Fisher exact test and the Mann-Whitney U test was performed.

RESULTS

Between August 1992 and January 2007, 682 aneurysms were selectively treated with coils in 668 patients. Procedure-related rupture occurred in 7 (11.7%) of 60 aneurysms < or = 3 mm, compared with 14 (2.3%) of 622 aneurysms > 3 mm (relative risk 5.2, 95% confidence interval 2.2-12.8; p < 0.001). Among cases with procedure-related rupture, inflation of a compliant balloon was associated with better outcome (Glasgow Outcome Scale Score > or = 4) compared with patients treated without balloon assistance (5 of 5 compared with 7 of 16; p = 0.05). Death resulting from procedure-related rupture occurred in 8 (38%) of 21 patients, and a vegetative state occurred in 1 patient. Clinical outcome was good in the other 12 patients (57%).

CONCLUSIONS

Endovascular coil embolization of very small (< or = 3 mm) ruptured cerebral aneurysms is 5 times more likely to result in procedure-related rupture compared with larger aneurysms. Balloon inflation for hemostasis may be associated with better outcome in the event of intraprocedural rupture and merits further study.