Predicting outcome in acute stroke with large vessel occlusion:application and validation of MR PREDICTS in the ESCAPE-NA1 population

Background: Predicting outcome after endovascular treatment for acute ischemic stroke is challenging. We aim to investigate differences between predicted and observed outcomes in patients with acute ischemic stroke treated with endovascular treatment and to evaluate the performance of a validated outcome prediction score. Patients and methods: MR PREDICTS is an outcome prediction tool based on a logistic regression model designed to predict the treatment benefit of endovascular treatment based on the MR CLEAN and HERMES populations. ESCAPE-NA1 is a randomized trial of nerinetide vs. placebo in patients with acute stroke and large vessel occlusion. We applied MR PREDICTS to patients in the control arm of ESCAPE-NA1. Model performance was assessed by calculating its discriminative ability and calibration. Results: Overall, 556/1105 patients (50.3%) in the ESCAPE-NA1-trial were randomized to the control arm, 435/556 (78.2%) were treated within 6 h of symptom onset. Good outcome (modified Rankin scale 0–2) at 3 months was achieved in 275/435 patients (63.2%), the predicted probability of good outcome was 52.5%. Baseline characteristics were similar in the study and model derivation cohort except for age (ESCAPE-NA1: mean: 70 y vs. HERMES: 66 y), hypertension (72% vs. 57%), and collaterals (good collaterals, 15% vs. 44%). Compared to HERMES we observed higher rates of successful reperfusion (TICI 2b-3, ESCAPE-NA1: 87% vs. HERMES: 71%) and faster times from symptom onset to reperfusion (median: 201 min vs. 286 min). Model performance was good, indicated by a c-statistic of 0.76 (95%confidence interval: 0.71–0.81). Conclusion: Outcome-prediction using models created from HERMES data, based on information available in the emergency department underestimated the actual outcome in patients with acute ischemic stroke and large vessel occlusion receiving endovascular treatment despite overall good model performance, which might be explained by differences in quality of and time to reperfusion. These findings underline the importance of timely and successful reperfusion for functional outcomes in acute stroke patients.</p

Door‐to‐Puncture: A Practical Metric for Capturing and Enhancing System Processes Associated With Endovascular Stroke Care, Preliminary Results From the Rapid Reperfusion Registry

Background: In 2011, the Brain Attack Coalition proposed door‐to‐treatment times of 2 hours as a benchmark for patients undergoing intra‐arterial therapy (IAT). We designed the Rapid Reperfusion Registry to capture the percentage of stroke patients who meet the target and its impact on outcomes. Methods and Results: This is a retrospective analysis of anterior circulation patients treated with IAT within 9 hours of symptom onset. Data was collected from December 31, 2011 to December 31, 2012 at 2 centers and from July 1, 2012 to December 31, 2012 at 7 centers. Short “Door‐to‐Puncture” (D2P) time was hypothesized to be associated with good patient outcomes. A total of 478 patients with a mean age of 68±14 years and median National Institutes of Health Stroke Scale (NIHSS) of 18 (IQR 14 to 21) were analyzed. The median times for IAT delivery were 234 minutes (IQR 163 to 304) for “last known normal‐to‐groin puncture” time (LKN‐to‐GP) and 112 minutes (IQR 68 to 176) for D2P time. The overall good outcome rate was 39.7% for the entire cohort. In a multivariable model adjusting for age, NIHSS, hypertension, diabetes, reperfusion status, and symptomatic hemorrhage, both short LKN‐to‐GP (OR 0.996; 95% CI [0.993 to 0.998]; P<0.001) and short D2P times (OR 0.993, 95% CI [0.990 to 0.996]; P<0.001) were associated with good outcomes. Only 52% of all patients in the registry achieved the targeted D2P time of 2 hours. Conclusions: The time interval of D2P presents a clinically relevant time frame by which system processes can be targeted to streamline the delivery of IAT care nationally. At present, there is much opportunity to enhance outcomes through reducing D2P

Rapid alteplase administration improves functional outcomes in patients with stroke due to large vessel occlusions

Background and Purpose: We report the relation of onset-to-treatment time and door-to-needle time with functional outcomes and mortality among patients with ischemic stroke with imaging-proven large vessel occlusion treated with intravenous alteplase. Methods: Individual patient-level data from the HERMES (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials) collaboration were pooled from 7 trials that randomized patients to mechanical thrombectomy added to best medical therapy versus best medical therapy alone. Analysis was restricted to patients who received alteplase directly at the endovascular hospital. The primary outcome was disability defined on the modified Rankin Scale at 3 months. Results: Among 601 patients, mean age was 66.0 years (SD, 13.9), 50% were women, and median National Institutes of Health Stroke Scale score was 17. Onset-to-treatment time was median 125 minutes (interquartile range, 90–170). Door-to-treatment time was median 38 minutes (interquartile range, 26–55). Each 60-minute onset-to-treatment time delay was associated with greater disability at 90 days; the odds of functional independence (modified Rankin Scale, 0–2) at 90 days was 0.82 (95% CI, 0.66–1.03). With each 60-minute delay in door-to-needle time; the odds of functional independence was 0.55 (95% CI, 0.37–0.81) at 90 days. The absolute decline in the rate of excellent outcome (modified Rankin Scale, 0–1 at 90 days) was 20.3 per 1000 patients treated per 15-minute delay in door-to-needle time. The adjusted absolute risk difference for a door-to-needle time &lt;30 minutes versus 30 to 60 minutes was 19.3% for independent outcome (number-needed-to-treat ≈5 to gain 1 additional good outcome). Symptomatic intracranial hemorrhage occurred in 3.4% of patients, without a significant time dependency: odds ratio, 0.74 (95% CI, 0.43–1.28). Conclusions: Faster intravenous thrombolysis delivery is associated with less disability at 3 months among patients with large vessel occlusion

Efficacy of endovascular thrombectomy in patients with M2 segment middle cerebral artery occlusions: meta-analysis of data from the HERMES Collaboration

Background: The Society of Neurointerventional Surgery revised its operational definition of emergent large vessel occlusion (ELVO) recently to include proximal M2 segment middle cerebral artery (MCA) occlusions. We sought to assess the benefit of endovascular thrombectomy (EVT) over best medical care for M2 segment MCA occlusion. Methods: Patient level data from trials in the HERMES Collaboration were included. The HERMES core laboratory identified patients with M2 segment MCA occlusions and further classified them as proximal versus distal, anterior versus posterior division, and dominant versus co-dominant versus non-dominant. Primary outcome was modified Rankin Scale (mRS) score 0–2 at 90 days. Secondary outcomes were modified Thrombolysis in Cerebral Infarction (mTICI) rates at end of procedure, 90-day mRS shift, 90-day mRS 0–1, 24 hours National Institute of Health Stroke Scale (NIHSS) score 0–2, symptomatic intracerebral hemorrhage (ICH), and death. Results: 130 patients with M2 MCA (proximal location n=116 vs distal n=14, anterior division n=72 vs posterior n=58, dominant n=73 vs co-dominant n=50 vs non-dominant n=7) were included. Successful reperfusion (mTICI 2b or 3) among those undergoing EVT was seen in 59.2% of patients. Treatment effect favored EVT (adjusted OR 2.39, 95% CI 1.08 to 5.28, p=0.03) for 90-day mRS 0–2 (58.2% EVT vs 39.7% control). Direction of benefit favored EVT for other outcomes. Treatment effect favoring EVT was maximal in patients with proximal M2 segment MCA occlusions (n=116, adjusted OR 2.68, 95% CI 1.13 to 6.37) and in dominant M2 segment MCA occlusions (n=73, adjusted OR 4.08, 95% CI 1.08 to 15.48). No sICH (0%) was observed in patients treated with EVT compared with five (7.9%) in the control arm. Conclusion: Patients with proximal M2 segment MCA occlusions eligible for EVT trial protocols benefited from EVT

Confirmatory study of time-dependent computed tomographic perfusion thresholds for use in acute ischemic stroke

Background and Purpose: Computed tomographic perfusion (CTP) thresholds associated with follow-up brain infarction may differ by time from symptom onset to imaging and reperfusion. We confirm CTP thresholds over time to imaging and reperfusion in patients with acute ischemic stroke from the HERMES collaboration (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials) data. Methods: Patients with occlusion on CT angiography were acutely imaged with CTP. Noncontrast CT and magnetic resonance-diffusion weighted imaging at 24 to 48 hours defined follow-up infarction. Reperfusion was assessed on conventional angiogram. Tmax, cerebral blood flow (CBF), and cerebral blood volume maps were derived from delay-insensitive CTP postprocessing. These parameters were analyzed using receiver operator characteristics to derive optimal thresholds based on time from stroke onset-to-CTP or to reperfusion. ANOVA and linear regression were used to test whether the derived CTP thresholds were different by time. Results: One hundred thirty-seven patients were included. Tmax thresholds of &gt;15.7 s and &gt;15.8 s and absolute CBF thresholds of &lt;8.9 and &lt;7.5 mL·min−1·100 g−1 for gray matter and white matter respectively were associated with infarct if reperfusion was achieved &lt;90 minutes from CTP with stroke onset-to-CTP &lt;180 minutes. The discriminative ability of cerebral blood volume was modest. There were no statistically significant relationships between stroke onset-to-CTP time and Tmax, CBF, and cerebral blood volume thresholds (all P&gt;0.05). A statistically significant relationship was observed between CTP-to-reperfusion time and the optimal thresholds for Tmax (P&lt;0.001) and CBF (P&lt;0.001). Similar but more modest relationship was noted for onset-to-reperfusion time and optimal thresholds for CBF (P≤0.01). Conclusions: CTP thresholds based on stroke onset and imaging time and taking into account time needed for reperfusion may improve infarct prediction in patients with acute ischemic stroke

Does sex modify the effect of endovascular treatment for ischemic stroke? A subgroup analysis of seven randomized trials

Background and Purpose: Previous studies have reported less favorable outcome and less effect of endovascular treatment (EVT) after ischemic stroke in women than in men. Our aim was to study the influence of sex on outcome and on the effect of EVT for ischemic stroke in recent randomized trials on EVT. Methods: We used data from 7 randomized controlled trials on EVT within the HERMES collaboration. The primary outcome was 90-day functional outcome (modified Rankin Scale). We compared baseline characteristics and outcomes between men and women. With ordinal logistic regression, we evaluated the association between EVT and 90-day functional outcome for men and women separately, adjusted for potential confounders. We tested for interaction between sex and EVT. Results: We included 1762 patients in the analyses, of whom 833 (47%) were women. Women were older (median, 70 versus 66 years; P&lt;0.001), were smoking less often (30% versus 44%; P&lt;0.001), and had higher collateral grades (grade 3: 46% versus 35%; P&lt;0.001) than men. Functional independence (modified Rankin Scale score, 0–2) at 90 days was reached by 318 women (39%) and 364 men (39%). The effect of EVT on the ordinal modified Rankin Scale was similar in women (adjusted common odds ratio [acOR], 2.13; 95% CI, 1.47–3.07) and men (acOR, 2.16; 95% CI, 1.59–2.96), with a P for interaction of 0.926. Conclusions: Sex does not influence clinical outcome after EVT and does not modify treatment effect of EVT. Therefore, sex should not be a consideration in the selection of patients for EVT

Quantified health and cost effects of faster endovascular treatment for large vessel ischemic stroke patients in the Netherlands

BACKGROUND: The effectiveness of endovascular treatment (EVT) for large vessel occlusion (LVO) stroke severely depends on time to treatment. However, it remains unclear what the value of faster treatment is in the years after index stroke. The aim of this study was to quantify the value of faster EVT in terms of health and healthcare costs for the Dutch LVO stroke population. METHODS: A Markov model was used to simulate 5-year follow-up functional outcome, measured with the modified Rankin Scale (mRS), of 69-year-old LVO patients. Post-treatment mRS was extracted from the MR CLEAN Registry (n=2892): costs per unit of time and Quality-Adjusted Life Years (QALYs) per mRS sub-score were retrieved from follow-up data of the MR CLEAN trial (n=500). Net Monetary Benefit (NMB) at a willingness to pay of €80 000 per QALY was reported as primary outcome, and secondary outcome measures were days of disability-free life gained and costs. RESULTS: EVT administered 1 min faster resulted in a median NMB of €309 (IQR: 226;389), 1.3 days of additional disability-free life (IQR: 1.0;1.6), while cumulative costs remained largely unchanged (median: -€15, IQR: -65;33) over a 5-year follow-up period. As costs over the follow-up period remained stable while QALYs decreased with longer time to treatment, which this results in a near-linear decrease of NMB. Since patients with faster EVT lived longer, they incurred more healthcare costs. CONCLUSION: One-minute faster EVT increases QALYs while cumulative costs remain largely unaffected. Therefore, faster EVT provides better value of care at no extra healthcare costs