Multicenter external validation of the ABCD2 score in triaging TIA patients

External validations of the ABCD2 score in prediction of stroke risk after transient ischemic attack. A Tunisian hospital-based cohort study

BACKGROUND AND PURPOSE

Identification of patients with high risk of stroke after transient ischemic attack (TIA) could be helpful to optimize stroke prevention. We aimed to externally validate the ABCD2 score for the prediction of stroke after TIA in a Tunisian population.

METHODS

We conducted a retrospective observational study of consecutive patients admitted for TIA in four university hospitals in Tunisia. Patients were screened for onset of stroke. Sensitivity, specificity, positive and negative predictive values with areas under the receiver operating characteristic (ROC) curves were calculated for risk of stroke at 2, 7, 30 and 90 days after the index event.

RESULTS

Of 415 patients screened in this study, the total cumulative subsequent stroke rates after TIA at 2, 7, 30 and 90 days were respectively, 4.8%, 10.6%, 13.5% and 20.2%. Using a cut-off value of 4, the ABCD2 showed an overall good sensitivity (95%, 97.7%, 96.4% and 97.6% respectively at 2, 7, 30 and 90 days). Areas under ROC cure of the ABCD2 score in patients with TIA for stroke onset at 2, 7, 30 and 90 days were respectively 0.67 (95% CI, 0.55-0.79), 0.79 (95% CI, 0.71-0.85), 0.79 (95% CI, 0.72-0.85), and 0.76 (95% CI, 0.70-0.81).

CONCLUSION

Our findings suggest that the ABCD2 score could be used in our population to discriminate patient with TIA at low and high risk of developing recurrent stroke.

Evaluation of ABCD2 score during the development of stroke in COVID-19 patients diagnosed with transient ischemic attack in the emergency department

BACKGROUND

The aim of the present study is to reveal the association between the risk of stroke using ABCD₂ score and COVID-19 in patients who presented to our emergency department during the pandemic and were diagnosed with TIA.

METHODS

According to the recommendations of the European Stroke Association, patients with an ABCD2 score of <4 were classified as low-risk, and patients with an ABCD2 score of ≥4 were classified as high-risk. Within 90 days of the patient's admission to the emergency room, the development of stroke was tracked and recorded on the system.

RESULTS

Stroke occurred in 35.78% of the patients. Regarding COVID-19, 75.34% of stroke patients were positive for COVID-19 and 65.75% had COVID-19 compatible pneumonia on 'thoracic CT'. Regarding mortality, 16.4% of the patients who were positive for COVID-19 and developed a stroke died. The presence of COVID-19 compatible pneumonia on thorax CT, PCR test result and ABCD2 score were determined as independent risk factors for the development of stroke. According to the PCR test results, the probability of having a stroke decreases 0.283 times in patients who are negative for COVID-19. According to the PCR test results, the probability of having a stroke increased 2.7 times in COVID-19 positive patients.

CONCLUSIONS

Adding the presence of COVID-19 and the presence of COVID-19 pneumonia to the ABCD₂ score, based on the information about the increased risk of stroke in TIA patients, improves the predictive power of the score. More studies are needed in this regard.

Risk of Subsequent Stroke Among Patients Receiving Outpatient vs Inpatient Care for Transient Ischemic Attack: A Systematic Review and Meta-analysis

IMPORTANCE

Transient ischemic attack (TIA) often indicates a high risk of subsequent cerebral ischemic events. Timely preventive measures improve the outcome.

OBJECTIVE

To estimate and compare the risk of subsequent ischemic stroke among patients with TIA or minor ischemic stroke (mIS) by care setting.

DATA SOURCES

MEDLINE, Web of Science, Scopus, Embase, International Clinical Trials Registry Platform, ClinicalTrials.gov, Trip Medical Database, CINAHL, and all Evidence-Based Medicine review series were searched from the inception of each database until October 1, 2020.

STUDY SELECTION

Studies evaluating the occurrence of ischemic stroke after TIA or mIS were included. Cohorts without data on evaluation time for reporting subsequent stroke, with retrospective diagnosis of the index event after stroke occurrence, and with a report of outcomes that were not limited to patients with TIA or mIS were excluded. Two authors independently screened the titles and abstracts and provided the list of candidate studies for full-text review; discrepancies and disagreements in all steps of the review were addressed by input from a third reviewer.

DATA EXTRACTION AND SYNTHESIS

The study was prepared and reported following the Preferred Reporting Items for Systematic Reviews and Meta-analyses, Meta-analysis of Observational Studies in Epidemiology, Methodological Expectations of Cochrane Intervention Reviews, and Enhancing the Quality and Transparency of Health Research guidelines. The Risk of Bias in Nonrandomized Studies-of Exposures (ROBINS-E) tool was used for critical appraisal of cohorts, and funnel plots, Begg-Mazumdar rank correlation, Kendall τ2, and the Egger bias test were used for evaluating the publication bias. All meta-analyses were conducted under random-effects models.

MAIN OUTCOMES AND MEASURES

Risk of subsequent ischemic stroke among patients with TIA or mIS who received care at rapid-access TIA or neurology clinics, inpatient units, emergency departments (EDs), and unspecified or multiple settings within 4 evaluation intervals (ie, 2, 7, 30, and 90 days).

RESULTS

The analysis included 226 683 patients from 71 articles recruited between 1981 and 2018; 5636 patients received care at TIA clinics (mean [SD] age, 65.7 [3.9] years; 2291 of 4513 [50.8%] men), 130 139 as inpatients (mean [SD] age, 78.3 [4.0] years; 49 458 of 128 745 [38.4%] men), 3605 at EDs (mean [SD] age, 68.9 [3.9] years; 1596 of 3046 [52.4%] men), and 87 303 patients received care in an unspecified setting (mean [SD] age, 70.8 [3.8] years, 43 495 of 87 303 [49.8%] men). Among the patients who were treated at a TIA clinic, the risk of subsequent stroke following a TIA or mIS was 0.3% (95% CI, 0.0%-1.2%) within 2 days, 1.0% (95% CI, 0.3%-2.0%) within 7 days, 1.3% (95% CI, 0.4%-2.6%) within 30 days, and 2.1% (95% CI, 1.4%-2.8%) within 90 days. Among the patients who were treated as inpatients, the risk of subsequent stroke was to 0.5% (95% CI, 0.1%-1.1%) within 2 days, 1.2% (95% CI, 0.4%-2.2%) within 7 days, 1.6% (95% CI, 0.6%-3.1%) within 30 days, and 2.8% (95% CI, 2.1%-3.5%) within 90 days. The risk of stroke among patients treated at TIA clinics was not significantly different from those hospitalized. Compared with the inpatient cohort, TIA clinic patients were younger and had had lower ABCD2 (age, blood pressure, clinical features, duration of TIA, diabetes) scores (inpatients with ABCD2 score >3, 1101 of 1806 [61.0%]; TIA clinic patients with ABCD2 score >3, 1933 of 3703 [52.2%]).

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis, the risk of subsequent stroke among patients who were evaluated in a TIA clinic was not higher than those hospitalized. Patients who received treatment in EDs without further follow-up had a higher risk of subsequent stroke. These findings suggest that TIA clinics can be an effective component of the TIA care component pathway.

A 5-Decade Analysis of Incidence Trends of Ischemic Stroke After Transient Ischemic Attack: A Systematic Review and Meta-analysis

Importance

Management of transient ischemic attack (TIA) has gained significant attention during the past 25 years after several landmark studies indicated the high incidence of a subsequent stroke.

Objective

To calculate the pooled event rate of subsequent ischemic stroke within 2, 7, 30, and 90 days of a TIA and compare this incidence among the population with TIA recruited before 1999 (group A), from 1999 to 2007 (group B), and after 2007 (group C).

Data Sources

All published studies of TIA outcomes were obtained by searching PubMed from 1996, to the last update on January 31, 2020, irrespective of the study design, document type, or language.

Study Selection

Of 11 516 identified citations, 175 articles were relevant to this review. Both the classic time-based definition of TIA and the new tissue-based definition were accepted. Studies with a combined record of patients with TIA and ischemic stroke, without clinical evaluation for the index TIA, with diagnosis of index TIA event after ischemic stroke occurrence, with low suspicion for TIA, or duplicate reports of the same database were excluded.

Data Extraction and Synthesis

The study was conducted and reported according to the PRISMA, MOOSE, and EQUATOR guidelines. Critical appraisal and methodological quality assessment used the Quality in Prognosis Studies tool. Publication bias was visualized by funnel plots and measured by the Begg-Mazumdar rank correlation Kendall τ2 statistic and Egger bias test. Data were pooled using double arcsine transformations, DerSimonian-Laird estimator, and random-effects models.

Main Outcomes and Measures

The proportion of the early ischemic stroke after TIA within 4 evaluation intervals (2, 7, 30, and 90 days) was considered as effect size.

Results

Systematic review yielded 68 unique studies with 223 866 unique patients from 1971 to 2019. The meta-analysis included 206 455 patients (58% women) during a span of 4 decades. The overall subsequent ischemic stroke incidence rates were estimated as 2.4% (95% CI, 1.8%-3.2%) within 2 days, 3.8% (95% CI, 2.5%-5.4%) within 7 days, 4.1% (95% CI, 2.4%-6.3%) within 30 days, and 4.7% (95% CI, 3.3%-6.4%) within 90 days. There was a recurrence risk of 3.4% among group A in comparison with 2.1% in group B or 2.1% in group C within 2 days; 5.5% in group A vs 2.9% in group B or 3.2% in group C within 7 days; 6.3% in group A vs 2.9% in group B or 3.4% in group C within 30 days, and 7.4% in group A vs 3.9% in group B or 3.9% in group C within 90 days.

Conclusions and Relevance

These findings suggest that TIA continues to be associated with a high risk of early stroke; however, the rate of post-TIA stroke might have decreased slightly during the past 2 decades.

Clinical Risk Score for Predicting Recurrence Following a Cerebral Ischemic Event

Introduction: Recurrent stroke has a higher rate of death and disability. A number of risk scores have been developed to predict short-term and long-term risk of stroke following an initial episode of stroke or transient ischemic attack (TIA) with limited clinical utilities. In this paper, we review different risk score models and discuss their validity and clinical utilities.

Methods: The PubMed bibliographic database was searched for original research articles on the various risk scores for risk of stroke following an initial episode of stroke or TIA. The validation of the models was evaluated by examining the internal and external validation process as well as statistical methodology, the study power, as well as the accuracy and metrics such as sensitivity and specificity.

Results: Different risk score models have been derived from different study populations. Validation studies for these risk scores have produced conflicting results. Currently, ABCD² score with diffusion weighted imaging (DWI) and Recurrence Risk Estimator at 90 days (RRE-90) are the two acceptable models for short-term risk prediction whereas Essen Stroke Risk Score (ESRS) and Stroke Prognosis Instrument-II (SPI-II) can be useful for prediction of long-term risk.

Conclusion: The clinical risk scores that currently exist for predicting short-term and long-term risk of recurrent cerebral ischemia are limited in their performance and clinical utilities. There is a need for a better predictive tool which can overcome the limitations of current predictive models. Application of machine learning methods in combination with electronic health records may provide platform for development of new-generation predictive tools.

When has service provision for transient ischaemic attack improved enough? A discrete event simulation economic modelling study

OBJECTIVES

The aim of this study was to examine the impact of transient ischaemic attack (TIA) service modification in two hospitals on costs and clinical outcomes.

DESIGN

Discrete event simulation model using data from routine electronic health records from 2011.

PARTICIPANTS

Patients with suspected TIA were followed from symptom onset to presentation, referral to specialist clinics, treatment and subsequent stroke.

INTERVENTIONS

Included existing versus previous (less same day clinics) and hypothetical service reconfiguration (7-day service with less availability of clinics per day).

OUTCOME MEASURES

The primary outcome of the model was the prevalence of major stroke after TIA. Secondary outcomes included service costs (including those of treating subsequent stroke) and time to treatment and attainment of national targets for service provision (proportion of high-risk patients (according to ABCD² score) seen within 24 hours).

RESULTS

The estimated costs of previous service provision for 490 patients (aged 74±12 years, 48.9% female and 23.6% high risk) per year at each site were £340 000 and £368 000, respectively. This resulted in 31% of high-risk patients seen within 24 hours of referral (47/150) with a median time from referral to clinic attendance/treatment of 1.15 days (IQR 0.93-2.88). The costs associated with the existing and hypothetical services decreased by £5000 at one site and increased £21 000 at the other site. Target attainment was improved to 79% (118/150). However, the median time to clinic attendance was only reduced to 0.85 days (IQR 0.17-0.99) and thus no appreciable impact on the modelled incidence of major stroke was observed (10.7 per year, 99% CI 10.5 to 10.9 (previous service) vs 10.6 per year, 99% CI 10.4 to 10.8 (existing service)).

CONCLUSIONS

Reconfiguration of services for TIA is effective at increasing target attainment, but in services which are already working efficiently (treating patients within 1-2 days), it has little estimated impact on clinical outcomes and increased investment may not be worthwhile.

Association of Ambulatory Blood Pressure Monitoring parameters with the Framingham Stroke Risk Profile

The Framingham Stroke Risk Profile (FSRP) is a novel and reliable tool for estimating the 10-year probability for incident stroke in stroke-free individuals, while the predictive value of ambulatory blood pressure monitoring (ABPM) for first-ever and recurrent stroke has been well established. We sought to evaluate cross-sectionally the association of ABPM parameters with FSRP score in a large sample of 2343 consecutive stroke-free individuals (mean age: 56.0±12.9, 49.1% male) who underwent 24-hour ABPM. True hypertensives showed significantly higher FSRP (11.2±5.0) compared to the normotensives (8.2±5.0, p<0.001), while subjects with white coat hypertension also had higher FSRP (10.2±4.7) than normotensives (8.2±5.0, p<0.001). Compared to dippers that exhibited the lowest FSRP, non-dippers and reverse-dippers exhibited significantly higher FSRP (9.8±4.8 for dippers vs 10.6±5.2 and 11.5±5.0 for non-dippers and reverse-dippers respectively, p≤0.001 for comparisons). In univariate analyses, the ABPM parameters that had the strongest correlation with FSRP were 24-hour (r=0.440, p<0.001), daytime (r=0.435, p<0.001) and night-time (r=0.423; p<0.001) pulse pressure (PP). The best fitting model for predicting FSRP (R²=24.6%) on multiple linear regression analyses after adjustment for vascular risk factors not included in FSRP comprised the following parameters in descending order: 24-hour PP (β=0.349, p<0.001), daytime SBP variability (β=0.124, p<0.001), 24-hour HR variability (β=-0.091, p<0.001), mean 24-hour HR (β=-0.107, p<0.001), BMI (β=0.081, p<0.001) and dipping percentage (β=-0.063, p=0.001). 24-hour PP and daytime SBP variability are the two ABPM parameters that were more strongly associated with FSRP-score. Reverse dippers had the highest FSRP among all dipping status profiles.

Motor Impairments in Transient Ischemic Attack Increase the Odds of a Subsequent Stroke: A Meta-Analysis

Background and purpose

Transient ischemic attack (TIA) increases the risk for a subsequent stroke. Typical symptoms include motor weakness, gait disturbance, and loss of coordination. The association between the presence of motor impairments during a TIA and the chances of a subsequent stroke has not been examined. In the current meta-analysis, we examine whether the odds of a stroke are greater in TIA individuals who experience motor impairments as compared with those who do not experience motor impairments.

Methods

We conducted a systematic search of electronic databases as well as manual searches of the reference lists of retrieved articles. The meta-analysis included studies that reported an odds ratio relating motor impairments to a subsequent stroke, or the number of individuals with or without motor impairments who experienced a subsequent stroke. We examined these studies using rigorous meta-analysis techniques including random effects model, forest and funnel plots, I², publication bias, and fail-safe analysis.

Results

Twenty-four studies with 15,129 participants from North America, Australia, Asia, and Europe qualified for inclusion. An odds ratio of 2.11 (95% CI, 1.67–2.65, p = 0.000) suggested that the chances of a subsequent stroke are increased by twofolds in individuals who experience motor impairments during a TIA compared with those individuals who have no motor impairments.

Conclusion

The presence of motor impairments during TIA is a significantly high-risk clinical characteristic for a subsequent stroke. The current evidence for motor impairments following TIA relies exclusively on the clinical reports of unilateral motor weakness. A comprehensive examination of motor impairments in TIA will enhance TIA prognosis and restoration of residual motor impairments.

High ABCD2 Scores and In-Hospital Interventions following Transient Ischemic Attack

Background and Purpose

Following transient ischemic attack (TIA), there is increased risk for ischemic stroke. The American Heart Association recommends admission of patients with ABCD² scores ≥3 for observation, rapid performance of diagnostic tests, and potential acute intervention. We aimed to determine if there is a relationship between ABCD² scores, in-hospital ischemic events, and in-hospital treatments after TIA admission.

Methods

We reviewed consecutive patients admitted between 2006 and 2011 following a TIA, defined as transient focal neurological symptoms attributed to a specific vascular distribution and lasting <24 h. Three interventions were prespecified: anticoagulation for atrial fibrillation, carotid or intracranial revascularization, and intravenous or intra-arterial reperfusion therapies. We compared rates of in-hospital recurrent TIA or ischemic stroke and the receipt of interventions among patients with low (<3) versus high (≥3) ABCD² scores.

Results

Of 249 patients, 11 patients (4.4%) had recurrent TIAs or strokes during their stay (8 TIAs, 3 strokes). All 11 had ABCD² scores ≥3, and no neurological events occurred in patients with lower scores (5.1 vs. 0%; p = 0.37). Twelve patients (4.8%) underwent revascularization for large artery stenosis, 16 (6.4%) were started on anticoagulants, and no patient received intravenous or intra-arterial reperfusion therapy. The ABCD² score was not associated with anticoagulation (p = 0.59) or revascularization (p = 0.20).

Conclusions

Higher ABCD² scores may predict early ischemic events after TIA but do not predict the need for intervention. Outpatient evaluation for those with scores <3 would potentially have delayed revascularization or anticoagulant treatment in nearly one-fifth of ‘low-risk’ patients.

Quality of Care and Ischemic Stroke Risk After Hospitalization for Transient Ischemic Attack: Findings From Get With The Guidelines-Stroke

BACKGROUND

Patients with transient ischemic attack (TIA) are at increased risk for ischemic stroke. We derived a prediction rule for 1-year ischemic stroke risk post-TIA, examining estimated risk, receipt of inpatient quality of care measures for TIA, and the presence or absence of stroke at 1 year post discharge.

METHODS AND RESULTS

We linked 67 892 TIA Get With The Guidelines-Stroke patients >65 years (2003-2008) to Medicare inpatient claims to obtain longitudinal outcomes. Using Cox proportional hazards modeling in a split sample, we identified baseline demographics and clinical characteristics associated with ischemic stroke admission during the year post-TIA, and developed a Get With The Guidelines Ischemic Stroke after TIA Risk Score; performance was examined in the validation sample. Quality of care was estimated by a global defect-free care measure, and individual performance measures within estimated risk score quintiles. The overall hospital admission rate for ischemic stroke during the year post-TIA was 5.7%. Patients with ischemic stroke were more likely to be older, black, and have higher rates of smoking, previous stroke, diabetes mellitus, previous myocardial infarction, heart failure, and atrial fibrillation. The Risk Score showed moderate discriminative performance (c-statistic=0.606); highest quintile patients were less likely to receive statins, smoking cessation counseling, and defect-free care. Although not associated with 1-year ischemic stroke, DCF was associated with a significantly lower risk of all-cause mortality.

CONCLUSIONS

TIA patients with high estimated ischemic stroke risk are less likely to receive defect-free care than low-risk patients. Standardized risk assessment and delivery of optimal inpatient care are needed to reduce this risk-treatment mismatch.

Statin pretreatment is associated with better outcomes in large artery atherosclerotic stroke

OBJECTIVE

Even though statin pretreatment is associated with better functional outcomes and lower risk of mortality in acute ischemic stroke, there are limited data evaluating this association in acute ischemic stroke due to large artery atherosclerosis (LAA), which carries the highest risk of early stroke recurrence.

METHODS

Consecutive patients with acute LAA were prospectively evaluated from 7 tertiary-care stroke centers during a 3-year period. Statin pretreatment, demographics, vascular risk factors, and admission and discharge stroke severity were recorded. The outcome events of interest were neurologic improvement during hospitalization (quantified as the relative decrease in NIH Stroke Scale score at discharge in comparison to hospital admission), favorable functional outcome (FFO) (defined as modified Rankin Scale score of 0-1), recurrent stroke, and death at 1 month. Statistical analyses were performed using univariable and multivariable Cox regression models adjusting for potential confounders. All analyses were repeated following propensity score matching.

RESULTS

Statin pretreatment was documented in 192 (37.2%) of 516 consecutive patients with LAA (mean age: 65 ± 13 years; 60.8% men; median NIH Stroke Scale score: 9 points, interquartile range: 5-18). Statin pretreatment was associated with greater neurologic improvement during hospitalization and higher rates of 30-day FFO in unmatched and matched (odds ratio for FFO: 2.44; 95% confidence interval [CI]: 1.07-5.53) analyses. It was also related to lower risk of 1-month mortality and stroke recurrence in unmatched and matched analyses (hazard ratio for recurrent stroke: 0.11, 95% CI: 0.02-0.46; hazard ratio for death: 0.24, 95% CI: 0.08-0.75).

CONCLUSION

Statin pretreatment in patients with acute LAA appears to be associated with better early outcomes regarding neurologic improvement, disability, survival, and stroke recurrence.

The Association Between Emergency Department Crowding and the Disposition of Patients With Transient Ischemic Attack or Minor Stroke

BACKGROUND

Emergency department (ED) crowding has been associated with adverse events, including short-term death and hospitalization among discharged patients. The mechanisms are poorly understood, but may include altered physician decision-making about ED discharge of higher-risk patients. One example is patients with transient ischemic attack (TIA) and minor stroke, who are at high risk of subsequent stroke. While hospitalization is frequently recommended, little consensus exists on which patients require admission.

OBJECTIVES

The authors sought to determine the association of ED crowding with the disposition of patients with minor stroke or TIA.

METHODS

This was a retrospective cohort study of prospectively collected data from the Registry of the Canadian Stroke Network at 12 EDs in Ontario, Canada, between 2003 and 2008, linked to administrative health databases. A hierarchical logistic regression model was used to determine the association between crowding at the time the patient was seen in the ED (defined as mean ED length of stay) and patient disposition (admission/discharge), after adjusting for patient and hospital-level variables.

RESULTS

The study cohort included 9,759 patients (4,607 with TIA and 5,152 with minor stroke); 49.5% were discharged from the ED. The mean (±SD) age of study patients was 70.78 (±13.40) years, with 52.9% being male, 37.3% arriving by emergency medical services, and 92.3% triaged as emergent or urgent. Greater severity of ED crowding was associated with a lower likelihood of discharge, regardless of ED size.

CONCLUSIONS

These results suggest that crowding may influence clinical decision-making in the disposition of patients with TIA or minor stroke and that, as crowding worsens, the likelihood of hospitalization increases.

ABCD2 score and secondary stroke prevention: meta-analysis and effect per 1,000 patients triaged

OBJECTIVE

Patients with TIA have high risk of recurrent stroke and require rapid assessment and treatment. The ABCD2 clinical risk prediction score is recommended for patient triage by stroke risk, but its ability to stratify by known risk factors and effect on clinic workload are unknown.

METHODS

We performed a systematic review and meta-analysis of all studies published between January 2005 and September 2014 that reported proportions of true TIA/minor stroke or mimics, risk factors, and recurrent stroke rates, dichotomized to ABCD2 score </≥4. We calculated the effect per 1,000 patients triaged on stroke prevention services.

RESULTS

Twenty-nine studies, 13,766 TIA patients (range 69-1,679), were relevant: 48% calculated the ABCD2 score retrospectively; few reported on the ABCD2 score's ability to identify TIA mimics or use by nonspecialists. Meta-analysis showed that ABCD2 ≥4 was sensitive (86.7%, 95% confidence interval [CI] 81.4%-90.7%) but not specific (35.4%, 95% CI 33.3%-37.6%) for recurrent stroke within 7 days. Additionally, 20% of patients with ABCD2 <4 had >50% carotid stenosis or atrial fibrillation (AF); 35%-41% of TIA mimics, and 66% of true TIAs, had ABCD2 score ≥4. Among 1,000 patients attending stroke prevention services, including the 45% with mimics, 52% of patients would have an ABCD2 score ≥4.

CONCLUSION

The ABCD2 score does not reliably discriminate those at low and high risk of early recurrent stroke, identify patients with carotid stenosis or AF needing urgent intervention, or streamline clinic workload. Stroke prevention services need adequate capacity for prompt specialist clinical assessment of all suspected TIA patients for correct patient management.

A simplified approach to the pooled analysis of calibration of clinical prediction rules for systematic reviews of validation studies

Objective

Estimating calibration performance of clinical prediction rules (CPRs) in systematic reviews of validation studies is not possible when predicted values are neither published nor accessible or sufficient or no individual participant or patient data are available. Our aims were to describe a simplified approach for outcomes prediction and calibration assessment and evaluate its functionality and validity.

Study design and methods:

Methodological study of systematic reviews of validation studies of CPRs: a) ABCD² rule for prediction of 7 day stroke; and b) CRB-65 rule for prediction of 30 day mortality. Predicted outcomes in a sample validation study were computed by CPR distribution patterns (“derivation model”). As confirmation, a logistic regression model (with derivation study coefficients) was applied to CPR-based dummy variables in the validation study. Meta-analysis of validation studies provided pooled estimates of “predicted:observed” risk ratios (RRs), 95% confidence intervals (CIs), and indexes of heterogeneity (I²) on forest plots (fixed and random effects models), with and without adjustment of intercepts. The above approach was also applied to the CRB-65 rule.

Results

Our simplified method, applied to ABCD² rule in three risk strata (low, 0–3; intermediate, 4–5; high, 6–7 points), indicated that predictions are identical to those computed by univariate, CPR-based logistic regression model. Discrimination was good (c-statistics =0.61–0.82), however, calibration in some studies was low. In such cases with miscalibration, the under-prediction (RRs =0.73–0.91, 95% CIs 0.41–1.48) could be further corrected by intercept adjustment to account for incidence differences. An improvement of both heterogeneities and P-values (Hosmer-Lemeshow goodness-of-fit test) was observed. Better calibration and improved pooled RRs (0.90–1.06), with narrower 95% CIs (0.57–1.41) were achieved.

Conclusion

Our results have an immediate clinical implication in situations when predicted outcomes in CPR validation studies are lacking or deficient by describing how such predictions can be obtained by everyone using the derivation study alone, without any need for highly specialized knowledge or sophisticated statistics.

An assessment of the cost-effectiveness of magnetic resonance, including diffusion-weighted imaging, in patients with transient ischaemic attack and minor stroke: a systematic review, meta-analysis and economic evaluation

BACKGROUND

Patients with transient ischaemic attack (TIA) or minor stroke need rapid treatment of risk factors to prevent recurrent stroke. ABCD2 score or magnetic resonance diffusion-weighted brain imaging (MR DWI) may help assessment and treatment.

OBJECTIVES

Is MR with DWI cost-effective in stroke prevention compared with computed tomography (CT) brain scanning in all patients, in specific subgroups or as 'one-stop' brain-carotid imaging? What is the current UK availability of services for stroke prevention?

DATA SOURCES

Published literature; stroke registries, audit and randomised clinical trials; national databases; survey of UK clinical and imaging services for stroke; expert opinion.

REVIEW METHODS

Systematic reviews and meta-analyses of published/unpublished data. Decision-analytic model of stroke prevention including on a 20-year time horizon including nine representative imaging scenarios.

RESULTS

The pooled recurrent stroke rate after TIA (53 studies, 30,558 patients) is 5.2% [95% confidence interval (CI) 3.9% to 5.9%] by 7 days, and 6.7% (5.2% to 8.7%) at 90 days. ABCD2 score does not identify patients with key stroke causes or identify mimics: 66% of specialist-diagnosed true TIAs and 35-41% of mimics had an ABCD2 score of ≥ 4; 20% of true TIAs with ABCD2 score of < 4 had key risk factors. MR DWI (45 studies, 9078 patients) showed an acute ischaemic lesion in 34.3% (95% CI 30.5% to 38.4%) of TIA, 69% of minor stroke patients, i.e. two-thirds of TIA patients are DWI negative. TIA mimics (16 studies, 14,542 patients) make up 40-45% of patients attending clinics. UK survey (45% response) showed most secondary prevention started prior to clinic, 85% of primary brain imaging was same-day CT; 51-54% of patients had MR, mostly additional to CT, on average 1 week later; 55% omitted blood-sensitive MR sequences. Compared with 'CT scan all patients' MR was more expensive and no more cost-effective, except for patients presenting at > 1 week after symptoms to diagnose haemorrhage; strategies that triaged patients with low ABCD2 scores for slow investigation or treated DWI-negative patients as non-TIA/minor stroke prevented fewer strokes and increased costs. 'One-stop' CT/MR angiographic-plus-brain imaging was not cost-effective.

LIMITATIONS

Data on sensitivity/specificity of MR in TIA/minor stroke, stroke costs, prognosis of TIA mimics and accuracy of ABCD2 score by non-specialists are sparse or absent; all analysis had substantial heterogeneity.

CONCLUSIONS

Magnetic resonance with DWI is not cost-effective for secondary stroke prevention. MR was most helpful in patients presenting at > 1 week after symptoms if blood-sensitive sequences were used. ABCD2 score is unlikely to facilitate patient triage by non-stroke specialists. Rapid specialist assessment, CT brain scanning and identification of serious underlying stroke causes is the most cost-effective stroke prevention strategy.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Dabigatran etexilate for secondary stroke prevention: the first year experience from a multicenter short-term registry

BACKGROUND

There are growing concerns for the side effects of dabigatran etexilate (dabigatran), including higher incidence of dyspepsia and gastrointestinal bleeding. We conducted a multicenter early implementation study to prospectively evaluate the safety, efficacy and adherence to dabigatran for secondary stroke prevention.

METHODS

Consecutive atrial fibrillation (AF) patients with ischemic stroke (IS) or transient ischemic attack (TIA) received dabigatran for secondary stroke prevention during their hospital stay according to American Heart Association recommendations at five tertiary care stroke centers. The study population was prospectively followed and outcomes were documented. The primary and secondary safety outcomes were major hemorrhage and all other bleeding events respectively defined according to RE-LY trial methodology.

RESULTS

A total of 78 AF patients (mean age 71 ± 9years; 54% men; 81% IS, 19% TIA; median CHADS2 (Congestive heart failure, Hypertension, diabetes mellitus, age >75 years, prior stroke or TIA); range 2-5) score 4 were treated with dabigatran [(110mg bid (74%); 150mg bid (26%)]. During a mean follow-up period of 7 ± 5 months (range 1-18) we documented no cases of IS, TIA, intracranial hemorrhage, systemic embolism or myocardial infarction in AF patients treated with dabigatran. There were two (2.6%) major bleeding events (lower gastrointestinal bleeding) and two (2.6%) minor bleedings [hematuria (n = 1) and rectal bleeding (n = 1)]. Dabigatran was discontinued in 26% of the study population with high cost being the most common reason for discontinuation (50%).

DISCUSSION

Our pilot data indicate that dabigatran appears to be safe for secondary stroke prevention during the first year of implementation of this therapy. However, high cost may limit the long-term treatment of AF patients with dabigatran, leading to early discontinuation.

Transient ischemic attacks: predictability of future ischemic stroke or transient ischemic attack events

The short-term risk of an ischemic stroke after a transient ischemic attack (TIA) is estimated to be approximately 3%–10% at 2 days, 5% at 7 days, and 9%–17% at 90 days, depending on active or passive ascertainment of ischemic stroke. Various risk prediction scores are available to identify high-risk patients. We present here a pragmatic review of the literature discussing the main scoring systems. We also provide the sensitivity, specificity, positive predictive value, and negative predictive value for each scoring system. Our review shows that scoring systems including brain imaging and vascular imaging are better at risk prediction than scores that do not include this information.

Racial disparities in early mortality in 1,134 young patients with acute stroke

We sought to investigate potential racial disparities in early outcomes of young individuals with stroke in an international multicenter study. We evaluated consecutive patients with first-ever acute stroke aged 18-45 years from prospective databases involving 12 tertiary-care stroke centers in North America (n = 2), Europe (n = 6), and Asia (n = 4). Demographics, vascular risk factors, stroke subtypes, pre-stroke functional status, stroke severity, blood pressure parameters, and serum glucose at hospital admission were documented. The outcome events of interest were 30-day mortality and 30-day favorable functional outcome (FFO) defined as modified-Rankin Scale score of 0-1. A total of 1,134 young adults (mean age 37.4 ± 7.0 years; 58.8 % men; 48.6 % Whites, 23.9 % Blacks, and 27.5 % Asians; median baseline National Institutes of Health Stroke Scale score 6 points, interquartile range 2-13) were included in the analyses. The 30-day stroke mortality and FFO rates differed (p < 0.001) across races. After adjusting for potential confounders, race was independently associated with 30-day mortality (p = 0.026) and 30-day FFO (p = 0.035). Blacks had a fourfold higher odds of 30-day stroke mortality in comparison to Asians (OR 4.00; 95 % CI 1.38-11.59; p = 0.011). Whites also had an increased likelihood of 30-day stroke mortality in comparison to Asians (OR 3.59; 95 % CI 1.28-10.03; p = 0.015). Blacks had a lower odds of 30-day FFO in comparison to Whites (OR 0.57; 95 % CI 0.35-0.91; p = 0.018). Racial disparities in early outcomes following first-ever stroke in young individuals appear to be independent of other known outcome predictor variables. Whites appear to have higher likelihood of 30-day FFO and Asians have lower odds of 30-day stroke mortality.

The ABCD2 score: a poor predictor of stroke risk in the emergency department

CLINICAL QUESTION

In patients presenting with transient ischemic attack in the emergency department, what is the accuracy of the ABCD2 score for predicting stroke?

ARTICLE CHOSEN

Perry JJ, Sharma M, Sivilotti ML, et al. Prospective validation of the ABCD2 score for patients in the emergency department with TIA. CMAJ 2011;183:1137-45.

OBJECTIVE

The study collaborators sought to externally validate the ABCD2 score as a tool for identifying patients seen in the emergency department with transient ischemic attack who are at high risk for stroke within 7 (primary outcome) and 90 (one of the secondary outcomes) days.

Frequent inaccuracies in ABCD2 scoring in non-stroke specialists' referrals to a daily Rapid Access Stroke Prevention service

The 'accuracy' of age, blood pressure, clinical features, duration and diabetes (ABCD(2)) scoring by non-stroke specialists referring patients to a daily Rapid Access Stroke Prevention (RASP) service is unclear, as is the accuracy of ABCD(2) scoring by trainee residents. In this prospective study, referrals were classified as 'confirmed TIAs' if the stroke specialist confirmed a clinical diagnosis of possible, probable or definite TIA, and 'non-TIAs' if patients had a TIA mimic or completed stroke. ABCD(2) scores from referring physicians were compared with scores by experienced stroke specialists and neurology/geriatric medicine residents at a daily RASP clinic; inter-observer agreement was examined. Data from 101 referrals were analysed (mean age=60.0years, 58% male). The median interval between referral and clinic assessment was 1day. Of 101 referrals, 52 (52%) were 'non-TIAs': 45 (86%) of 52 were 'TIA mimics' and 7 (14%) of 52 were completed strokes. There was only 'fair' agreement in total ABCD(2) scoring between referring physicians and stroke specialists (κ=0.37). Agreement was 'excellent' between residents and stroke specialists (κ=0.91). Twenty of 29 patients scored as 'moderate to high risk' (score 4-6) by stroke specialists were scored 'low risk' (score 0-3) by referring physicians. ABCD(2) scoring by referring doctors is frequently inaccurate, with a tendency to underestimate stroke risk. These findings emphasise the importance of urgent specialist assessment of suspected TIA patients, and that ABCD(2) scores by non-stroke specialists cannot be relied upon in isolation to risk-stratify patients. Inter-observer agreement in ABCD(2) scoring was 'excellent' between residents and stroke specialists, indicating short-term training may improve accuracy.

Association of ultrasonographic parameters with subclinical white-matter hyperintensities in hypertensive patients

Background and Purpose. Cerebral white matter hyperintensities (WMHs) are regarded as typical MRI expressions of small-vessel disease (SVD) and are common in hypertensive patients. Hypertension induces pathologic changes in macrocirculation and in microcirculation. Changes in microcirculation may lead to SVD of brain and consequently to hypertensive end-organ damage. This damage is regarded the result of interactions between the macrovascular and microvascular levels. We sought to investigate the association of cerebral WMHs with ultrasonographic parameters of cerebral macrocirculation evaluated by carotid duplex ultrasound (CDU) and transcranial doppler (TCD). Subjects and Methods. The study was prospective, cross-sectional and consecutive and included hypertensive patients with brain MRI with WMHs. Patients underwent CDU and TCD. The clinical variables recorded were demographic characteristics (age, gender, race) and vascular risk factors (hypertension, diabetic mellitus, hypercholesterolemia, current smoking, and body mass index). Excluded from the study were patients with history of clinical stroke (including lacunar stroke and hemorrhagic) or transient ischemic attack (either hemispheric or ocular), hemodynamically significant (>50%) extra- or intracranial stenosis, potential sources of cardioembolism, and absent transtemporal windows. WMHs were quantified with the use of a semiquantitative visual rating method. Ultrasound parameters investigated were (1) common carotid artery (CCA) diameter and intima-media thickness, (2) blood flow velocity in the CCA and internal carotid artery (ICA), and (3) blood flow velocity and pulsatility index of middle cerebral artery (MCA). Results. A total of 52 patients fulfilled the study inclusion criteria (mean age 71.4 ± 4.5 years, 54% men, median WMH-score: 20). The only two ultrasound parameters that were independently associated with WMH score in multivariate linear regression models adjusting for demographic characteristics and vascular risk factors were increased mean common carotid artery (CCA) diameter (beta = 0.784, SE = 0.272, P = 0.006, R² = 23.9%) and increased middle cerebral artery pulsatility index (MCA-PI; beta = 0.262, SE = 0.110, P = 0.025, R² = 9.0%). Among all ultrasound parameters the highest AUC (areas under the receiver operating characteristic curve) were documented for MCA-PI (AUC = 0.82, 95% CI = 0.68−0.95, P < 0.001) and mean CCA diameter (AUC = 0.80, 95% CI = 0.67−0.92, P < 0.001). Conclusions. Our study showed that in hypertensive individuals with brain SVD the extent of structural changes in cerebral microcirculation as reflected by WMHs burden is associated with the following ultrasound parameters of cerebral macrocirculation: CCA diameter and MCA-PI.

Prevalence of symptomatic intracranial atherosclerosis in Caucasians: a prospective, multicenter, transcranial Doppler study

BACKGROUND

There are limited data available regarding symptomatic intracranial atherosclerosis (SIA) prevalence in Caucasians. We sought to investigate SIA prevalence among Caucasian patients hospitalized with acute cerebral ischemia (ACI) in a prospective, multicenter Transcranial Doppler sonography (TCD) study.

METHODS

Consecutive patients with ACI were prospectively evaluated with TCD over a 24-month-period. The previously validated criteria of SONIA trial were used for detection of >50% intracranial stenosis with TCD. Brain angiography was performed to confirm the diagnosis in cases with abnormal TCD findings. SIA was diagnosed when there was evidence of a cerebral infarction in the territory of the stenotic artery (identified by TCD and confirmed by Magnetic resonance angiography [MRA]/Computed tomography angiography [CTA]).

RESULTS

A total of 467 consecutive patients with ACI (60.4% men, mean age 58 ± 14 years) were evaluated. SIA was documented in 43 patients (9.2%; 95%CI: 6.9%-12.2%). The most common SIA location was M1MCA (34.9%) followed by TICA (18.8%). Diabetes mellitus (OR: 4.25, 95%CI: 2.18-8.26; P < .001) and hypertension (OR: 2.41, 95%CI: 1.02-5.67; P = .045) were independently associated with SIA on multivariate models adjusting for potential confounders.

CONCLUSIONS

SIA was identified in almost 10% of patients admitted with symptoms of ACI. These preliminary findings support further collaborative initiatives among stroke physicians to increase the yield of SIA detection in Caucasian patients with ACI.

Improving the prediction of stroke or death after transient ischemic attack (TIA) by adding diffusion-weighted imaging lesions and TIA etiology to the ABCD2 score

The present study investigated the addition of transient ischemic attack (TIA) etiology and diffusion-weighted imaging (DWI) to the ABCD2 score, creating the ABCDE+ score, to improve the predictive ability of stroke risk or death at 6 months after TIA. We performed a cohort study of 150 consecutive patients with TIA. All patients underwent DWI and all had an etiologic workup and were followed up for 6 months. The area under the receiver operating characteristic curve (AUC) was used to compare the scores' ability to predict the outcome of stroke or death. Multivariate Cox regression analysis was performed to evaluate the association between the measured variables and subsequent stroke or death. Thirty patients (20%) experienced future stroke, and 12 patients (8%) died within the 6-month follow-up. A comparison of AUCs demonstrated the superiority of the ABCDE+ score over the ABCD2 score for predicting stroke (0.64 vs 0.60) and for predicting death (0.62 vs 0.56). ABCD2 score >4, ABCDE+ score >6, large-artery disease, and lesions detected on DWI were found to be independent predictors of future stroke, and ABCDE+ score >6, age, and heart disease were independent predictors of death. We conclude that incorporating DWI positivity and etiology of TIA into the ABCD2 score can improve the ability to predict stroke and death within 6 months after TIA.

Clopidogrel load for emboli reduction in patients with symptomatic carotid stenosis undergoing urgent carotid endarterectomy

BACKGROUND AND PURPOSE

Microembolic signals (MES) on transcranial Doppler are an independent risk factor for recurrent stroke in patients with extracranial symptomatic/asymptomatic carotid artery stenosis (CARAS). Clopidogrel load (300 mg) combined with dual antiplatelet therapy has been shown to reduce MES in patients with symptomatic CARAS. We sought to determine feasibility of clopidogrel load in decreasing asymptomatic embolization in patients with symptomatic CARAS undergoing urgent carotid endarterectomy within the first 2 weeks from the index event. Subjects and

METHODS

Consecutive patients with symptomatic CARAS (70%-99%) and presence of MES on 1-hour baseline (<24 hours from the index event) transcranial Doppler monitoring of ipsilateral middle cerebral artery were treated with clopidogrel load followed by clopidogrel (75 mg)±aspirin (100 mg) during the elapsed time period between hospital admission and urgent carotid endarterectomy at 3 tertiary-care stroke centers. Repeat 1-hour transcranial Doppler monitoring was performed the day before surgery. Bleeding complications during surgery and recurrent strokes or transient ischemic attacks during the first month of ictus were prospectively recorded.

RESULTS

A total of 11 symptomatic CARAS patients (mean age, 66±7 years; 73% men; 64% acute ischemic strokes) were treated with clopidogrel load followed by dual (67%) or single (33%) antiplatelet therapy. MES count was significantly reduced between baseline (median count, 8 MES/h; interquartile range, 6-19) and repeat transcranial Doppler monitoring (0 MES/h; interquartile range, 0-3; P=0.003). No bleeding complications, recurrent strokes, or transient ischemic attacks were documented.

CONCLUSIONS

Our pilot observational study provides preliminary nonrandomized data regarding the potential efficacy of clopidogrel load to reduce asymptomatic embolization in patients with symptomatic CARAS before urgent carotid endarterectomy.

Prognostic value of the ABCD² clinical prediction rule: a systematic review and meta-analysis

OBJECTIVE

The purpose of this systematic review with meta-analysis is to determine the predictive value of the ABCD ²at 7 and 90 days across three strata of risk. Background. The risk of stroke after transient ischaemic attack (TIA) is significant. The ABCD ²clinical prediction rule is designed to predict early risk of stroke after TIA. A number of independent validation studies have been conducted since the rule was derived.

METHODS

A systematic literature search was conducted to identify studies that validated the ABCD². The derived rule was used as a predictive model and applied to subsequent validation studies. Comparisons were made between observed and predicted number of strokes stratified by risk group: low (0-3 points), moderate (4-5 points) and high (6-7 points). Pooled results are presented as risk ratios (RRs) with 95% confidence intervals (CIs), in terms of over-prediction (RR > 1) or under-prediction (RR < 1) of stroke at 7 and 90 days.

RESULTS

We include 16 validation studies. Fourteen studies report 7-day stroke risk (n = 6282, 388 strokes). The ABCD² rule correctly predicts occurrence of stroke at 7 days across all three risk strata: low [RR 0.86, 95% CI (0.47-1.58), I² = 16%], moderate [RR 0.99, 95% CI (0.67-1.47), I² = 68%] and high [RR 0.84, 95% CI (0.6-1.19), I² = 46%]. Eleven studies report 90-day stroke risk (n = 6304). There is a non-significant trend towards over-prediction of stroke in all risk categories at 90 days. There are 426 strokes observed in contrast to a predicted 626 strokes. As the trichotomized ABCD² score increases, the risk of stroke increases (P < 0.01). There is no evidence of publication bias in these studies (P > 0.05).

CONCLUSION

The ABCD² is a useful CPR, particularly in relation to 7-day risk of stroke.

Prospective validation of the ABCD2 score for patients in the emergency department with transient ischemic attack

BACKGROUND

The ABCD2 score (Age, Blood pressure, Clinical features, Duration of symptoms and Diabetes) is used to identify patients having a transient ischemic attack who are at high risk for imminent stroke. However, despite its widespread implementation, the ABCD2 score has not yet been prospectively validated. We assessed the accuracy of the ABCD2 score for predicting stroke at 7 (primary outcome) and 90 days.

METHODS

This prospective cohort study enrolled adults from eight Canadian emergency departments who had received a diagnosis of transient ischemic attack. Physicians completed data forms with the ABCD2 score before disposition. The outcome criterion, stroke, was established by a treating neurologist or by an Adjudication Committee. We calculated the sensitivity and specificity for predicting stroke 7 and 90 days after visiting the emergency department using the original "high-risk" cutpoint of an ABCD2 score of more than 5, and the American Heart Association recommendation of a score of more than 2.

RESULTS

We enrolled 2056 patients (mean age 68.0 yr, 1046 (50.9%) women) who had a rate of stroke of 1.8% at 7 days and 3.2% at 90 days. An ABCD2 score of more than 5 had a sensitivity of 31.6% (95% confidence interval [CI] 19.1-47.5) for stroke at 7 days and 29.2% (95% CI 19.6-41.2) for stroke at 90 days. An ABCD2 score of more than 2 resulted in sensitivity of 94.7% (95% CI 82.7-98.5) for stroke at 7 days with a specificity of 12.5% (95% CI 11.2-14.1). The accuracy of the ABCD2 score as calculated by either the enrolling physician (area under the curve 0.56; 95% CI 0.47-0.65) or the coordinating centre (area under the curve 0.65; 95% CI 0.57-0.73) was poor.

INTERPRETATION

This multicentre prospective study involving patients in emergency departments with transient ischemic attack found the ABCD2 score to be inaccurate, at any cut-point, as a predictor of imminent stroke. Furthermore, the ABCD2 score of more than 2 that is recommended by the American Heart Association is nonspecific.

Transient ischaemic attack clinics and management of transient ischaemic attacks

PURPOSE OF REVIEW

The aim is to review transient ischaemic attack (TIA) clinics, other service delivery models, and current TIA management.

RECENT FINDINGS

Urgent assessment of TIA patients by stroke specialist services reduces stroke risk and is cost-effective. Almost one-third of TIA patients wait more than 24 h before presenting to medical attention, with delay associated with higher stroke risk. Risk stratification following suspected TIA may be performed by clinical assessment of individual patient characteristics, combined with the validated ABCD2 score (pre-investigation), and the ABCD3-I score (postinvestigation) in secondary care settings. Brain MRI and transcranial Doppler ultrasound add information related to vascular territory, TIA mechanism, and prognosis. Variability in systolic blood pressure in treated and untreated patients is an important predictor of stroke risk, independently of mean blood pressure.

SUMMARY

Daily specialist-provided TIA services delivered in clinic or inpatient settings have proven efficacy for stroke prevention. In addition, a rapid-access, clinic-based service is associated with cost savings and reduced hospital bed-day utilization after TIA.

Factors associated with time delay to carotid stenting in patients with a symptomatic carotid artery stenosis

Treatment of a symptomatic stenosis is known to be most beneficial within 14 days after the presenting event but this can frequently not be achieved in daily practice. The aim of this study was the assessment of factors responsible for this time delay to treatment. A retrospective analysis of a prospective two-center CAS database was carried out to investigate the potential factors that influence a delayed CAS treatment. Of 374 patients with a symptomatic carotid stenosis, 59.1% were treated beyond ≥14 days. A retinal TIA event (OR = 3.59, 95% CI 1.47–8.74, p < 0.01) was found to be a predictor for a delayed treatment, whereas the year of the intervention (OR = 0.32, 95% CI 0.20–0.50, p < 0.01) and a contralateral carotid occlusion (OR = 0.42, 95% CI 0.21–0.86, p = 0.02) were predictive of an early treatment. Similarly, within the subgroup of patients with transient symptoms, the year of the intervention (OR = 0.28, 95% CI 0.14–0.59, p < 0.01) was associated with an early treatment, whereas a retinal TIA as the qualifying event (OR = 6.96, 95% CI 2.37–20.47, p < 0.01) was associated with a delayed treatment. Treatment delay was most pronounced in patients with an amaurosis fugax, whereas a contralateral carotid occlusion led to an early intervention. Although CAS is increasingly performed faster in the last years, there is still scope for an even more accelerated treatment strategy, which might prevent future recurrent strokes prior to treatment.