Contribution and additional impact of imaging to the SPAN-100 score

Symptomatic Intracranial Hemorrhage After Endovascular Stroke Treatment: External Validation of Prediction Models

BACKGROUND

Symptomatic intracranial hemorrhage (sICH) is a severe complication of reperfusion therapy for ischemic stroke. Multiple models have been developed to predict sICH or intracranial hemorrhage (ICH) after reperfusion therapy. We provide an overview of published models and validate their ability to predict sICH in patients treated with endovascular treatment in daily clinical practice.

METHODS

We conducted a systematic search to identify models either developed or validated to predict sICH or ICH after reperfusion therapy (intravenous thrombolysis and/or endovascular treatment) for ischemic stroke. Models were externally validated in the MR CLEAN Registry (n=3180; Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands). The primary outcome was sICH according to the Heidelberg Bleeding Classification. Model performance was evaluated with discrimination (c-statistic, ideally 1; a c-statistic below 0.7 is considered poor in discrimination) and calibration (slope, ideally 1, and intercept, ideally 0).

RESULTS

We included 39 studies describing 40 models. The most frequently used predictors were baseline National Institutes of Health Stroke Scale (NIHSS; n=35), age (n=22), and glucose level (n=22). In the MR CLEAN Registry, sICH occurred in 188/3180 (5.9%) patients. Discrimination ranged from 0.51 (SPAN-100 [Stroke Prognostication Using Age and National Institutes of Health Stroke Scale]) to 0.61 (SITS-SICH [Safe Implementation of Treatments in Stroke Symptomatic Intracerebral Hemorrhage] and STARTING-SICH [STARTING Symptomatic Intracerebral Hemorrhage]). Best calibrated models were IST-3 (intercept, -0.15 [95% CI, -0.01 to -0.31]; slope, 0.80 [95% CI, 0.50-1.09]), SITS-SICH (intercept, 0.15 [95% CI, -0.01 to 0.30]; slope, 0.62 [95% CI, 0.38-0.87]), and STARTING-SICH (intercept, -0.03 [95% CI, -0.19 to 0.12]; slope, 0.56 [95% CI, 0.35-0.76]).

CONCLUSIONS

The investigated models to predict sICH or ICH discriminate poorly between patients with a low and high risk of sICH after endovascular treatment in daily clinical practice and are, therefore, not clinically useful for this patient population.

Application of machine learning-based models to boost the predictive power of the SPAN index

BACKGROUND

This study re-explored the predictive validity of Stroke Prognostication using Age and National Institutes of Health Stroke Scale (SPAN) index in patients who received different treatments for acute ischemic stroke (AIS) and developed machine learning-boosted outcome prediction models.

METHODS

We evaluated the prognostic relevance of SPAN index in patients with AIS who received intravenous tissue-type plasminogen activator (IV-tPA), intra-arterial thrombolysis (IAT) or non-thrombolytic treatments (non-tPA), and applied machine learning algorithms to develop SPAN-based outcome prediction models in a cohort of 2145 hospitalized AIS patients. The performance of the models was assessed and compared using the area under the receiver operating characteristic curves (AUCs).

RESULTS

SPAN index ≥100 was associated with higher mortality rate and higher modified Rankin Scale at discharge in AIS patients who received the different treatments. Compared to the lower AUCs for the SPAN-alone model across all groups, the AUCs of the logistic regression-boosted model were 0.838, 0.857, 0.766 and 0.875 for the whole cohort, non-tPA, IV-tPA and IAT groups, respectively. Similarly, the AUCs of the generated artificial neural network were 0.846, 0.858, 0.785 and 0.859 for the whole cohort, non-tPA, IV-tPA and IAT groups, respectively, while for gradient boosting decision tree model, we computed 0.850, 0.863, 0.779 and 0.815.

CONCLUSIONS

SPAN index has prognostic relevance in patients with AIS who received different treatments. The generated machine learning-based models exhibit good performance for predicting the functional recovery of AIS; thus, their proposed clinical application to aid outcome prediction and decision-making for the patients with AIS.

Evaluation of stroke prognostication using age and NIH Stroke Scale index (SPAN-100 index) in delayed intravenous thrombolysis patients (beyond 4.5 hours)

OBJECTIVES

the efficacy of delayed intravenous tissue plasminogen activator (tPA), beyond the 4.5 h window, is evolving. Advanced age and high admission National Institutes of Health Stroke Scale (NIHSS) score are proposed to adversely affect the outcome of delayed thrombolysis and limit the inclusion criteria. The summation of patient age and admission NIHSS score was introduced as the SPAN-100 index as a tool of prediction of the clinical outcome after acute ischemic stroke (AIS). We aimed to assess the SPAN-100 index in AIS thrombolysed patients after 4.5 h.

MATERIALS AND METHODS

The SPAN-100 index was applied to AIS patients receiving delayed IV thrombolysis (IVT) after 4.5 h. Patients demographics, risk factors, clinical, laboratory and radiological data, mismatch evidence, treatment onset and modality, NIHSS score at baseline and at discharge, and 3 months follow-up modified Rankin Scale (mRS) were reviewed. SPAN-100 score ≥ 100 is classified as SPAN-100 positive while score < 100 is SPAN-100 negative. Clinical outcomes, death and intracerebral hemorrhage (ICH) incidences were compared between SPAN-100 positive and negative groups.

RESULTS

SPAN-100-positive delayed IVT-patients (11/136) had a 6-fold increased risk for unfavorable outcome compared to SPAN-negative patients (OR 6.34; 95% CI 1.59-25.24 p=0.004), however there was no relation between the SPAN-100 positivity and mortality or ICH.

CONCLUSION

SPAN-100-positive patients are more likely to achieve non-favorable outcome with delayed IVT in comparison to the SPAN-100-negative patients. SPAN-100 index may influence the eligibility criteria of delayed thrombolysis.

Validation and comparison of prognostic scales in Chinese patients with ischemic stroke: a prospective study from CATIS

BACKGROUND

: Various tools are currently available to quantify the risks of adverse clinical outcomes after an ischemic stroke. This study aimed to validate and compare prognostic scales among Chinese patients with ischemic stroke.

METHODS

: We compared three stroke prognostic scales (Stroke Prognostication using Age and the National Institutes of Health Stroke Scale-100 [SPAN-100], Totaled Health Risks in Vascular Events [THRIVE], and Acute Stroke Registry and Analysis of Lausanne [ASTRAL]) in 3870 Chinese patients with ischemic stroke from the China Antihypertensive Trial in Acute Ischemic Stroke (CATIS). The 2-year primary outcome was a combination of death and major disability (modified Rankin Scale score ≥3).

RESULTS

: Among all the scales, the ASTRAL score had the best accuracy for predicting 2-year prognosis in Chinese patients with ischemic stroke. The C-statistic of the ASTRAL score for the 2-year primary outcome was 0.79 (95% confidence interval [CI]: 0.78-0.80), and the Hosmer-Lemeshow goodness-of-fit test showed that the ASTRAL score fitted Chinese patients with ischemic stroke well (χ² = 9.83, P = 0.277). The incidences of the primary outcome in the <5%, 5%-9.9%, 10%-19.9%, and ≥20% risk groups based on the ASTRAL scores were 3.93%, 7.55%, 14.29%, and 41.81%, respectively (odds ratio: 1.23; 95% CI: 1.21-1.26; P < 0.001).

CONCLUSION

: The ASTRAL score had higher efficacy than the SPAN-100 and THRIVE scores in predicting 2-year adverse outcomes among Chinese patients with ischemic stroke, suggesting that it could be a valuable risk assessment tool for the 2-year prognosis of such patients.

A Simple Hospital Mobility Scale for Acute Ischemic Stroke Patients Predicts Long-term Functional Outcome

Background. Stroke patients present restriction of mobility in the acute phase, and the use of a simple and specific scale can be useful to guide rehabilitation. Objective. To validate and propose a Hospital Mobility Scale (HMS) for ischemic stroke patients as well as to evaluate the HMS as a prognostic indicator. Methods. This study was performed in 2 phases: in the first, we developed the HMS content, and in the second, we defined its score and evaluated its psychometric properties. We performed a longitudinal prospective study consisting of 2 cohorts (derivation and validation cohorts). The data were collected in a stroke unit, and the following scales were applied during hospitalization: National Institutes of Health Stroke Scale to quantify stroke severity and the HMS to verify the degree of mobility. The primary outcome was the proportion of unfavorable functional outcomes, defined as a modified Barthel Index of <95. Results. We defined 3 tasks for HMS: sitting, standing, and gait. In the derivation cohort, the HMS presented an accuracy of 84.5% measured using the area under the receiver operating characteristic curve (95% CI = 78.3-90.7; P < .001), whereas in the validation cohort the accuracy was 87.8% (95% CI = 81.9%-93.7%; P < .001). The HMS presented a large standardized effect size (1.41) and excellent interexaminer agreement (intraclass correlation coefficient = 0.962; 95% CI = 0.917-0.983; P < .001). Conclusion. The HMS was able to predict accurately the functional outcome of poststroke patients, presented excellent interexaminer agreement, and was sensitive in detecting changes.

Re-evaluation of the stroke prognostication using age and NIH Stroke Scale index (SPAN-100 index) in IVT patients - the-SPAN 10065 index

Background

The SPAN-100 index adds patient age and baseline NIHSS-score and was introduced to predict clinical outcome after acute ischemic stroke (AIS). Even with high NIHSS-scores younger patients cannot reach a SPAN-100-positive status (index ≥100). We aimed to evaluate the SPAN-100 index among a large, contemporary cohort of i.v.-thrombolysed AIS-patients and exclusively among older patients who can at least theoretically achieve SPAN-100-positivity.

Methods

The SPAN-100 index was applied to AIS-patients receiving i.v.-thrombolysis (IVT) in our institution between 01/2006 and 01/2013. Clinical outcome and symptomatic intracerebral hemorrhage rates were compared between SPAN-100-positive and -negative patients. Furthermore we excluded patients < 65 years, without any theoretical chance to achieve SPAN-100-positivity, and re-evaluated the index (SPAN⁶⁵–100 index).

Results

SPAN-100-positive IVT-patients (124/1002) had a 9-fold increased risk for unfavorable outcome compared to SPAN-negative patients (OR 9.39; 95% CI 5.87–15.02; p <  0.001). The odds ratio for mortality was 7.48 (95% CI 4.90–11.43; p <  0.001). No association was found between SPAN-100-positivity and sICH-incidence (OR 0.88; 95% CI 0.31–2.53; p = 0.810).

SPAN⁶⁵–100-positivity (124/741) was associated with an 8-fold increased risk for unfavorable outcome (OR 7.6; 95% CI 4.71–12.22; p <  0.001) but not associated with higher sICH-rates (OR 0.86; 95% CI 0.29–2.53; p <  0.001).

Conclusions

Also for patients ≥65 years the SPAN-100 index can be a fast, easy method to predict clinical outcome of IVT-patients in everyday practice. However, it should not be used to determine the risk of sICH after IVT. Based on a SPAN-positive status IVT should not be withheld from AIS-patients merely because of feared sICH-complications.

Thrombus Migration in the Middle Cerebral Artery: Incidence, Imaging Signs, and Impact on Success of Endovascular Thrombectomy

BACKGROUND

Thrombus migration (TM) in intracranial vessels during ischemic stroke has been reported in the form of case reports, but its incidence, impact on the technical success of subsequent endovascular thrombectomy and patients' outcome have never been studied systematically.

METHODS AND RESULTS

Retrospective analysis was done of 409 patients with isolated middle cerebral artery occlusions treated with endovascular thrombectomy. TM was observed (1) by analyzing discrepancies between computed tomographic angiography and digital subtraction angiography and (2) by comparing infarct pattern in the striatocapsular region with exact, angiographically assessed thrombus location within the M1-segment and the involvement of the middle cerebral artery perforators. Preinterventional infarction of discrepant regions (infarction in regions supplied by more proximal vessels than those occluded by the clot) was ensured by carefully reviewing available preinterventional multimodal imaging. Adequate imaging inclusion criteria were met by 325 patients. Ninety-seven patients showed signs of TM (26 with direct evidence, 71 with indirect evidence). There was no difference in the frequency of preinterventional intravenous recombinant tissue plasminogen activator administration between patients with TM and those without (63.9% vs 64.9%, P=0.899). TM was associated with lower rates of complete reperfusion (Thrombolysis in Cerebral Infarction score 3) (adjusted odds ratio 0.400, 95% CI 0.226-0.707). Subsequently, preinterventional TM was associated with lower rates of substantial neurologic improvement (adjusted odds ratio 0.541, 95% CI 0.309-0.946).

CONCLUSIONS

Preinterventional TM does not seem to be facilitated by intravenous recombinant tissue plasminogen activator and often occurs spontaneously. However, TM is associated with the risk of incomplete reperfusion in subsequent thrombectomy, suggesting increased clot fragility. Occurrence of TM may thereby have a substantial impact on the outcome of endovascularly treated stroke patients.

Good collateral circulation predicts favorable outcomes in intravenous thrombolysis: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Baseline collateral status has been correlated with outcomes of acute ischaemic stroke patients receiving intravenous thrombolysis (IVT) in previous studies. We carried out the current systematic review and meta-analysis to synthesize currently available evidence regarding such correlations.

METHODS

Full-text articles published since 2000 were retrieved and screened. The overall effect sizes of good versus poor collateral status over a series of outcomes and certain baseline features were estimated by random-effects models and presented in risk ratios (RRs) or mean differences.

RESULTS

Overall, 28 (3057 patients) and 14 (1584 patients) studies were included in qualitative and quantitative synthesis, respectively. Compared with poor pre-treatment collateral status, good collaterals showed a beneficial effect over the primary outcome of a favorable functional outcome at 3 or 6 months [RR, 2.45; 95% confidence interval, 1.94-3.09; P < 0.001] in acute ischaemic stroke patients receiving IVT treatment. However, such an effect tended to be different between studies with prescribed time windows of 3, 4.5 and > 4.5 h (up to 7 h), with the RRs being 2.21, 2.48 and 5.00, respectively (I²  = 53%). Good pre-treatment collaterals were also associated with a smaller infarct size at baseline, and a lower rate of symptomatic intracranial hemorrhage and a higher rate of neurological improvement early after IVT treatment.

CONCLUSIONS

The present study has demonstrated the prognostic value of baseline collateral circulation for outcomes of acute ischaemic stroke patients receiving intravenous reperfusion therapies, studied with different time windows of up to 7 h after ictus for IVT therapy.