Budget impact of endovascular treatment for acute ischaemic stroke patients in the Netherlands for 2015-2021.

INTRODUCTION: Endovascular treatment (EVT) has been proven to be both effective and cost-effective for patients with acute ischaemic stroke. We investigated the budget impact of large-scale implementation of EVT for acute ischaemic stroke patients in the Netherlands for 2015-2021. METHODS: An analysis was performed from a healthcare perspective as a preplanned substudy of the Multicenter Randomized Clinical trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN). Estimated yearly costs during follow-up after stroke for patients who had or had not been treated with EVT as add-on to usual care were linked to numbers of new patients retrieved from 2 Dutch registries of EVT that started after the last inclusion in MR CLEAN (2014). Aggregated costs and costs per care sector were calculated based on prevalence using a population dynamic tool. RESULTS: From 2015, the yearly number of new acute ischaemic stroke patients receiving EVT increased almost threefold, from 812 in 2015 to 2,370 in 2021. The introduction of EVT plus usual care resulted in estimated net annual savings that increased from €â€¯2.9 million in 2015 to €â€¯58 million in 2021. CONCLUSION: Offering EVT as add-on to usual care for acute ischaemic stroke patients was increasingly cost saving from a national healthcare perspective but affected distinct healthcare sectors differently.

Economic Evaluation of Endovascular Treatment for Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Endovascular treatment for acute ischemic stroke has been proven clinically effective, but evidence of the cost-effectiveness based on real-world data is scarce. The aim of this study was to assess whether endovascular therapy plus usual care is cost-effective in comparison to usual care alone in acute ischemic stroke patients. METHODS: An economic evaluation was performed from a societal perspective with a 2-year time horizon. Empirical data on health outcomes and the use of resources following endovascular treatment were gathered parallel to the MR CLEAN trial (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) and its 2-year follow-up study. Incremental cost-effectiveness ratios were calculated as the extra costs per additional patient with functional independence (modified Rankin Scale score 0-2) and the extra cost per quality-adjusted life year gained. RESULTS: The mean costs per patient in the intervention group were $126 494 versus $143 331 in the control group (mean difference, -$16 839 [95% CI, -$38 113 to $5456]). Compared with patients in the control group, more patients in the intervention group achieved functional independence, 37.2% versus 23.9% (absolute difference, 13.3% [95% CI, 4.0%-22.0%]) and they generated more quality-adjusted life years, 0.99 versus 0.83 (mean difference of 0.16 [95% CI, 0.04-0.29]). Endovascular treatment dominated standard treatment with $18 233 saved per extra patient with a good outcome and $105 869 saved per additional quality-adjusted life year. CONCLUSIONS: Endovascular treatment added to usual care is clinically effective, and cost saving in comparison to usual care alone in patients with acute ischemic stroke. Registration: URL: https://www.trialregister.nl/trial/695; Unique identifier: NL695. URL: https://www.isrctn.com; Unique identifier: ISRCTN10888758.

Two-Year Outcome after Endovascular Treatment for Acute Ischemic Stroke.

BACKGROUND: Several trials involving patients with acute ischemic stroke have shown better functional outcomes with endovascular treatment than with conventional treatment at 90 days after initiation of treatment. However, results on long-term clinical outcomes are lacking. METHODS: We assessed clinical outcomes 2 years after patients were randomly assigned to receive either endovascular treatment (intervention group) or conventional treatment (control group) for acute ischemic stroke. The primary outcome was the score on the modified Rankin scale at 2 years; this scale measures functional outcome, with scores ranging from 0 (no symptoms) to 6 (death). Secondary outcomes included all-cause mortality and the quality of life at 2 years, as measured by means of a health utility index that is based on the European Quality of Life-5 Dimensions questionnaire (scores range from -0.329 to 1, with higher scores indicating better health). RESULTS: Of the 500 patients who underwent randomization in the original trial, 2-year data for this extended follow-up trial were available for 391 patients (78.2%) and information on death was available for 459 patients (91.8%). The distribution of outcomes on the modified Rankin scale favored endovascular treatment over conventional treatment (adjusted common odds ratio, 1.68; 95% confidence interval [CI], 1.15 to 2.45; P=0.007). There was no significant difference between the treatment groups in the percentage of patients who had an excellent outcome (i.e., a modified Rankin scale score of 0 or 1). The mean quality-of-life score was 0.48 among patients randomly assigned to endovascular treatment as compared with 0.38 among patients randomly assigned to conventional treatment (mean difference, 0.10; 95% CI, 0.03 to 0.16; P=0.006). The cumulative 2-year mortality rate was 26.0% in the intervention group and 31.0% in the control group (adjusted hazard ratio, 0.9; 95% CI, 0.6 to 1.2; P=0.46). CONCLUSIONS: In this extended follow-up trial, the beneficial effect of endovascular treatment on functional outcome at 2 years in patients with acute ischemic stroke was similar to that reported at 90 days in the original trial. (Funded by the Netherlands Organization for Health Research and Development and others; MR CLEAN Current Controlled Trials number, ISRCTN10888758 , and Netherlands Trial Register number, NTR1804 , and MR CLEAN extended follow-up trial Netherlands Trial Register number, NTR5073 .).

A randomized trial of intraarterial treatment for acute ischemic stroke.

BACKGROUND: In patients with acute ischemic stroke caused by a proximal intracranial arterial occlusion, intraarterial treatment is highly effective for emergency revascularization. However, proof of a beneficial effect on functional outcome is lacking. METHODS: We randomly assigned eligible patients to either intraarterial treatment plus usual care or usual care alone. Eligible patients had a proximal arterial occlusion in the anterior cerebral circulation that was confirmed on vessel imaging and that could be treated intraarterially within 6 hours after symptom onset. The primary outcome was the modified Rankin scale score at 90 days; this categorical scale measures functional outcome, with scores ranging from 0 (no symptoms) to 6 (death). The treatment effect was estimated with ordinal logistic regression as a common odds ratio, adjusted for prespecified prognostic factors. The adjusted common odds ratio measured the likelihood that intraarterial treatment would lead to lower modified Rankin scores, as compared with usual care alone (shift analysis). RESULTS: We enrolled 500 patients at 16 medical centers in The Netherlands (233 assigned to intraarterial treatment and 267 to usual care alone). The mean age was 65 years (range, 23 to 96), and 445 patients (89.0%) were treated with intravenous alteplase before randomization. Retrievable stents were used in 190 of the 233 patients (81.5%) assigned to intraarterial treatment. The adjusted common odds ratio was 1.67 (95% confidence interval [CI], 1.21 to 2.30). There was an absolute difference of 13.5 percentage points (95% CI, 5.9 to 21.2) in the rate of functional independence (modified Rankin score, 0 to 2) in favor of the intervention (32.6% vs. 19.1%). There were no significant differences in mortality or the occurrence of symptomatic intracerebral hemorrhage. CONCLUSIONS: In patients with acute ischemic stroke caused by a proximal intracranial occlusion of the anterior circulation, intraarterial treatment administered within 6 hours after stroke onset was effective and safe. (Funded by the Dutch Heart Foundation and others; MR CLEAN Netherlands Trial Registry number, NTR1804, and Current Controlled Trials number, ISRCTN10888758.).

Extracranial Carotid Disease and Effect of Intra-arterial Treatment in Patients With Proximal Anterior Circulation Stroke in MR CLEAN.

Background: The presence of extracranial carotid disease (ECD) is associated with less favorable clinical outcomes in patients with acute ischemic stroke caused by intracranial proximal occlusion. Acute intra-arterial treatment (IAT) in the setting of extracranial and intracranial lesions is considered challenging, and whether it yields improved outcomes remains uncertain. Objective: To examine whether the presence of ECD modified the effect of IAT for intracranial proximal anterior circulation occlusion. Design: Prespecified subgroup analysis of a randomized clinical trial of endovascular treatment for acute ischemic stroke in the Netherlands. (Trial registrations: NTR1804 [Netherlands Trial Register] and ISRCTN10888758). Setting: 16 hospitals in the Netherlands. Patients: Acute ischemic stroke caused by proximal intracranial arterial occlusion of the anterior circulation. Extracranial carotid disease was defined as cervical internal carotid artery stenosis (>50%) or occlusion. Intervention: IAT treatment versus no IAT. Measurements: The primary outcome was functional outcome, as measured by the modified Rankin Scale at 90 days and reported as adjusted common odds ratio (acOR) for a shift in direction of a better outcome. Multivariable ordinal logistic regression analysis with an interaction term was used to estimate treatment effect modification by ECD. Results: The overall acOR was 1.67 (95% CI, 1.21 to 2.30) in favor of the intervention. The acOR was 3.1 (CI, 1.7 to 5.8) in the prespecified subgroup of patients with ECD versus 1.3 (CI, 0.9 to 1.9) in patients presenting without ECD. Both acORs are in favor of the intervention (P for interaction = 0.07). Limitation: The study was not powered for subgroup analysis. Conclusion: Intra-arterial treatment may be at least as effective in patients with ECD as in those without ECD, and it should not be withheld in these complex patients with acute ischemic stroke. Primary Funding Source: Dutch Heart Foundation, AngioCare BV, Medtronic/Covidien/EV3, MEDAC Gmbh/LAMEPRO, Penumbra, Stryker, and Top Medical/Concentric.

Admission Glucose and Effect of Intra-Arterial Treatment in Patients With Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Hyperglycemia on admission is common after ischemic stroke. It is associated with unfavorable outcome after treatment with intravenous thrombolysis and after intra-arterial treatment. Whether hyperglycemia influences the effect of reperfusion treatment is unknown. We assessed whether increased admission serum glucose modifies the effect of intra-arterial treatment in patients with acute ischemic stroke. METHODS: We used data from the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands). Hyperglycemia was defined as admission serum glucose >7.8 mmol/L. The primary outcome measure was the adjusted common odds ratio for a shift in the direction of a better outcome on the modified Rankin Scale at 90 days, estimated with ordinal logistic regression. Secondary outcome variable was symptomatic intracranial hemorrhage. We assessed treatment effect modification of hyperglycemia and admission serum glucose levels with multiplicative interaction factors and adjusted for prognostic variables. RESULTS: Four hundred eighty-seven patients were included. Mean admission serum glucose was 7.2 mmol/L (SD, 2.2). Fifty-seven of 226 patients (25%) randomized to intra-arterial treatment were hyperglycemic compared with 61 of 261 patients (23%) in the control group. The interaction of either hyperglycemia or admission serum glucose levels and treatment effect on modified Rankin Scale scores was not significant (P=0.67 and P=0.87, respectively). The same applied for occurrence of symptomatic hemorrhage (P=0.39 for hyperglycemia, P=0.39 for admission serum glucose). CONCLUSIONS: We found no evidence for effect modification of intra-arterial treatment by admission serum glucose in patients with acute ischemic stroke. CLINICAL TRIAL REGISTRATION: URL: www.isrctn.com. Unique identifier: ISRCTN10888758.

Baseline Blood Pressure Effect on the Benefit and Safety of Intra-Arterial Treatment in MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands).

BACKGROUND AND PURPOSE: High blood pressure (BP) is associated with poor outcome and the occurrence of symptomatic intracranial hemorrhage in acute ischemic stroke. Whether BP influences the benefit or safety of intra-arterial treatment (IAT) is not known. We aimed to assess the relation of BP with functional outcome, occurrence of symptomatic intracranial hemorrhage and effect of IAT. METHODS: This is a post hoc analysis of the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands). BP was measured at baseline, before IAT or stroke unit admission. We estimated the association of baseline BP with the score on the modified Rankin Scale at 90 days and safety parameters with ordinal and logistic regression analysis. Effect of BP on the effect of IAT was tested with multiplicative interaction terms. RESULTS: Systolic BP (SBP) had the best correlation with functional outcome. This correlation was U-shaped; both low and high baseline SBP were associated with poor functional outcome. Higher SBP was associated with symptomatic intracranial hemorrhage (adjusted odds ratio, 1.25 for every 10 mm Hg higher SBP [95% confidence interval, 1.09-1.44]). Between SBP and IAT, there was no interaction for functional outcome, symptomatic intracranial hemorrhage, or other safety parameters; the absolute benefit of IAT was evident for the whole SBP range. The same was found for diastolic BP. CONCLUSIONS: BP does not affect the benefit or safety of IAT in patients with acute ischemic stroke caused by proximal intracranial vessel occlusion. Our data provide no arguments to withhold or delay IAT based on BP. CLINICAL TRIAL REGISTRATION: URL: http://www.isrctn.com. Unique identifier: ISRCTN10888758.

Endovascular thrombectomy after large-vessel ischaemic stroke: a meta-analysis of individual patient data from five randomised trials.

BACKGROUND: In 2015, five randomised trials showed efficacy of endovascular thrombectomy over standard medical care in patients with acute ischaemic stroke caused by occlusion of arteries of the proximal anterior circulation. In this meta-analysis we, the trial investigators, aimed to pool individual patient data from these trials to address remaining questions about whether the therapy is efficacious across the diverse populations included. METHODS: We formed the HERMES collaboration to pool patient-level data from five trials (MR CLEAN, ESCAPE, REVASCAT, SWIFT PRIME, and EXTEND IA) done between December, 2010, and December, 2014. In these trials, patients with acute ischaemic stroke caused by occlusion of the proximal anterior artery circulation were randomly assigned to receive either endovascular thrombectomy within 12 h of symptom onset or standard care (control), with a primary outcome of reduced disability on the modified Rankin Scale (mRS) at 90 days. By direct access to the study databases, we extracted individual patient data that we used to assess the primary outcome of reduced disability on mRS at 90 days in the pooled population and examine heterogeneity of this treatment effect across prespecified subgroups. To account for between-trial variance we used mixed-effects modelling with random effects for parameters of interest. We then used mixed-effects ordinal logistic regression models to calculate common odds ratios (cOR) for the primary outcome in the whole population (shift analysis) and in subgroups after adjustment for age, sex, baseline stroke severity (National Institutes of Health Stroke Scale score), site of occlusion (internal carotid artery vs M1 segment of middle cerebral artery vs M2 segment of middle cerebral artery), intravenous alteplase (yes vs no), baseline Alberta Stroke Program Early CT score, and time from stroke onset to randomisation. FINDINGS: We analysed individual data for 1287 patients (634 assigned to endovascular thrombectomy, 653 assigned to control). Endovascular thrombectomy led to significantly reduced disability at 90 days compared with control (adjusted cOR 2.49, 95% CI 1.76-3.53; p<0.0001). The number needed to treat with endovascular thrombectomy to reduce disability by at least one level on mRS for one patient was 2.6. Subgroup analysis of the primary endpoint showed no heterogeneity of treatment effect across prespecified subgroups for reduced disability (pinteraction=0.43). Effect sizes favouring endovascular thrombectomy over control were present in several strata of special interest, including in patients aged 80 years or older (cOR 3.68, 95% CI 1.95-6.92), those randomised more than 300 min after symptom onset (1.76, 1.05-2.97), and those not eligible for intravenous alteplase (2.43, 1.30-4.55). Mortality at 90 days and risk of parenchymal haematoma and symptomatic intracranial haemorrhage did not differ between populations. INTERPRETATION: Endovascular thrombectomy is of benefit to most patients with acute ischaemic stroke caused by occlusion of the proximal anterior circulation, irrespective of patient characteristics or geographical location. These findings will have global implications on structuring systems of care to provide timely treatment to patients with acute ischaemic stroke due to large vessel occlusion. FUNDING: Medtronic.

Influence of Device Choice on the Effect of Intra-Arterial Treatment for Acute Ischemic Stroke in MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands).

BACKGROUND AND PURPOSE: Intra-arterial treatment by means of retrievable stents has been proven safe and effective. In MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands), the choice of the type of thrombectomy device was left to the discretion of the interventionist. The aim of this study was to explore the differences in functional outcome, neurological recovery, reperfusion, extent of infarction, and adverse events according to stent type and make. METHODS: The primary outcome was functional outcome at 90 days, assessed with the modified Rankin Scale (mRS). Neuroimaging outcomes included occlusion on computed tomographic angiography at 24 hours, infarct volume at 5 to 7 days, and modified thrombolysis in cerebral infarction scores. Safety outcomes included death within 90 days and any symptomatic intracerebral hemorrhage. We analyzed possible interactions between stent type and treatment with multiple regression models. Treatment effects were adjusted for patient age, stroke severity, and collateral score. RESULTS: Of the 500 patients included in the trial, 233 were allocated to intervention. Of these, 124 (53%) were first treated with Trevo (adjusted common odds ratio for shift on the mRS [acOR, 1.98; 95% confidence interval, 1.30-2.92]), 31 (13%) with Solitaire (acOR, 1.90; 95% confidence interval, 0.97-3.73), 40 (17%) with other retrievable stents or mechanical devices (acOR, 0.96; 95% confidence interval, 0.51-3.93], and 38 (16%) could not be treated. There was no interaction between device and treatment effect on functional outcome and all other secondary and safety outcomes. CONCLUSIONS: We found no evidence for a differential effect of thrombectomy for acute ischemic stroke by type of stent. CLINICAL TRIAL REGISTRATION: URL: http://www.isrctn.com. Unique identifier: ISRCTN10888758.

Clot Burden Score on Baseline Computerized Tomographic Angiography and Intra-Arterial Treatment Effect in Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: A high clot burden score (CBS) is associated with favorable outcome after intravenous treatment for acute ischemic stroke. The added benefit of intra-arterial treatment might be less in these patients. The aim of this exploratory post hoc analysis was to assess the relation of CBS with neurological improvement and endovascular treatment effect. METHODS: For 499 of 500 patients in the MR CLEAN study (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands), the CBS was determined. Ordinal logistic regression models with and without main baseline prognostic variables were used to assess the association between CBS (continuous or dichotomized at CBS of 6) and a shift toward better outcome on the modified Rankin Scale. The model without main baseline prognostic variables only included treatment allocation and CBS. Models with and without a multiplicative interaction term of CBS and treatment were compared using the χ2 test to assess treatment effect modification by CBS. RESULTS: Higher CBS was associated with a shift toward better outcome on the modified Rankin Scale; adjusted common odds ratio per point CBS was 1.12 (95% confidence interval, 1.04-1.20]. Dichotomized CBS had an adjusted common odds ratio of 1.67 (95% confidence interval, 1.12-2.51). Both effect estimates were slightly attenuated by adding baseline prognostic variables. The addition of the interaction terms did not significantly improve the fit of the models. There was a small and insignificant increase of intra-arterial treatment efficacy in the high CBS group. CONCLUSIONS: A higher CBS is associated with improved outcome and may be used as a prognostic marker. We found no evidence that CBS modifies the effect of intra-arterial treatment. CLINICAL TRIAL REGISTRATION: URL: http://www.trialregister.nl. Unique identifier: NTR1804. URL: http://www.controlled-trials.com. Unique identifier: ISRCTN10888758.

Collateral Status on Baseline Computed Tomographic Angiography and Intra-Arterial Treatment Effect in Patients With Proximal Anterior Circulation Stroke.

BACKGROUND AND PURPOSE: Recent randomized trials have proven the benefit of intra-arterial treatment (IAT) with retrievable stents in acute ischemic stroke. Patients with poor or absent collaterals (preexistent anastomoses to maintain blood flow in case of a primary vessel occlusion) may gain less clinical benefit from IAT. In this post hoc analysis, we aimed to assess whether the effect of IAT was modified by collateral status on baseline computed tomographic angiography in the Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN). METHODS: MR CLEAN was a multicenter, randomized trial of IAT versus no IAT. Primary outcome was the modified Rankin Scale at 90 days. The primary effect parameter was the adjusted common odds ratio for a shift in direction of a better outcome on the modified Rankin Scale. Collaterals were graded from 0 (absent) to 3 (good). We used multivariable ordinal logistic regression analysis with interaction terms to estimate treatment effect modification by collateral status. RESULTS: We found a significant modification of treatment effect by collaterals (P=0.038). The strongest benefit (adjusted common odds ratio 3.2 [95% confidence intervals 1.7-6.2]) was found in patients with good collaterals (grade 3). The adjusted common odds ratio was 1.6 [95% confidence intervals 1.0-2.7] for moderate collaterals (grade 2), 1.2 [95% confidence intervals 0.7-2.3] for poor collaterals (grade 1), and 1.0 [95% confidence intervals 0.1-8.7] for patients with absent collaterals (grade 0). CONCLUSIONS: In MR CLEAN, baseline computed tomographic angiography collateral status modified the treatment effect. The benefit of IAT was greatest in patients with good collaterals on baseline computed tomographic angiography. Treatment benefit appeared less and may be absent in patients with absent or poor collaterals. CLINICAL TRIAL REGISTRATION: URL: http://www.trialregister.nl and http://www.controlled-trials.com. Unique identifier: (NTR)1804 and ISRCTN10888758, respectively.

The effect of age on outcome after intra-arterial treatment in acute ischemic stroke: a MR CLEAN pretrial study.

BACKGROUND: In recent randomized controlled trials (RCTs) intra-arterial treatment (IAT) has been proven effective and safe for patients with acute ischemic stroke (AIS). So far, there seemed to be no interaction between older age (>80) and main treatment effect. We studied the association of older age with outcome and adverse events after IAT in a cohort of intra arterially treated patients. METHODS AND FINDINGS: Data from all AIS patients with proven proximal anterior circulation cerebral artery occlusion who were intra arterially treated between 2002 until the start of the MR CLEAN trial were studied retrospectively. Duration of the procedure, recanalization (Thrombolysis In Cerebral Infarction score (TICI)), early neurological recovery (i.e. decrease on NIHSS of ≥ 8 points) after one week or at discharge, good functional outcome at discharge by modified Rankin Scale (mRS ≤ 2) and the occurrence of neurological and non-neurological adverse events were assessed and the association with age was investigated. In total 315 patients met our inclusion criteria. Median age was 63 years (range 22-93) and 17 patients (5.4%) were over 80. Age was inversely associated with good functional outcome (adjusted Odds Ratio (aOR) 0.80, 95% CI: 0.66-0.98) for every 10 years increase of age. Age was not associated with longer duration of the procedure, lower recanalization rate or less early neurological recovery. The risk of all adverse events (aOR 1.27; 95% CI: 1.08-1.50) and non-neurological adverse events (aOR 1.34; 95% CI: 1.11-1.61) increased, but that of peri-procedural adverse events (aOR 0.79; 95% CI: 0.66-0.94) decreased with age. CONCLUSION: Higher age is inversely associated with good functional outcome after IAT in patients with AIS. However, treatment related adverse events are not related to age. These findings may help decision making when considering treatment of older patients with AIS.

Evolution of Intra-arterial Therapy for Acute Ischemic Stroke in The Netherlands: MR CLEAN Pretrial Experience.

INTRODUCTION: The Multicenter Randomized Clinical trial of Endovascular treatment for Acute ischemic stroke in the Netherlands (MR CLEAN) trial showed efficacy of intra-arterial (IA) treatment in acute ischemic stroke (AIS). We studied the evolution of IA treatment for AIS and its effects on clinical outcome and recanalization in The Netherlands in the pre-MR CLEAN era. METHODS: Data on 517 patients with AIS treated with IA therapy were collected retrospectively from all intervention centers in The Netherlands from 2002 to the start of participation in the MR CLEAN trial. Clinical outcome was measured by means of the modified Rankin Scale score and recanalization with the Thrombolysis in Cerebral Infarction Scale. RESULTS: IA therapy was first used in patients with basilar artery occlusion. Over the years, there was a gradual increase in the number of anterior circulation strokes treated. There was a shift in applied therapies from primary IA therapy to combined intravenous and IA therapy and from IA thrombolysis to mechanical thrombectomy. Time from symptom onset to treatment decreased. Recanalization rates gradually increased. At the same time, there was a trend toward more favorable outcomes after 3 months and fewer deceased patients both at discharge and after 3 months. However, none of these changes reached statistical significance. CONCLUSION: The treatment approach used in the MR CLEAN trial was the result of an evolution of practise in the preceding years, with gradual improvement in technical and clinical outcomes.

Type of anesthesia and differences in clinical outcome after intra-arterial treatment for ischemic stroke.

BACKGROUND AND PURPOSE: Intra-arterial treatment (IAT) in patients with acute ischemic stroke (AIS) can be performed with or without general anesthesia (GA). Previous studies suggested that IAT without the use of GA (non-GA) is associated with better clinical outcome. Nevertheless, no consensus exists about the anesthetic management during IAT of AIS patients. This study investigates the association between type of anesthesia and clinical outcome in a large cohort of patients with AIS treated with IAT. METHODS: All consecutive patients with AIS of the anterior circulation who received IAT between 2002 and 2013 in 16 Dutch hospitals were included in the study. Primary outcome was functional outcome on the modified Rankin Scale at discharge. Difference in primary outcome between GA and non-GA was estimated using multiple ordinal regression analysis, adjusting for age, stroke severity, occlusion of the internal carotid artery terminus, previous stroke, atrial fibrillation, and diabetes mellitus. RESULTS: Three hundred forty-eight patients were included in the analysis; 70 patients received GA and 278 patients did not receive GA. Non-GA was significantly associated with good clinical outcome (odds ratio 2.1, 95% confidence interval 1.02-4.31). After adjusting for prespecified prognostic factors, the point estimate remained similar; statistical significance, however, was lost (odds ratio 1.9, 95% confidence interval 0.89-4.24). CONCLUSIONS: Our study suggests that patients with AIS of the anterior circulation undergoing IAT without GA have a higher probability of good clinical outcome compared with patients treated with general anesthesia.

Influence of the interventionist's experience on outcomes of endovascular thrombectomy in acute ischemic stroke: results from the MR CLEAN Registry.

BACKGROUND: The relationship between the interventionist's experience and outcomes of endovascular thrombectomy (EVT) for acute ischemic stroke of the anterior circulation, is unclear. OBJECTIVE: To assess the effect of the interventionist's level of experience on clinical, imaging, and workflow outcomes. Secondly, to determine which of the three experience definitions is most strongly associated with these outcome measures. METHODS: We analysed data from 2700 patients, included in the MR CLEAN Registry. We defined interventionist's experience as the number of procedures performed in the year preceding the intervention (EXPfreq), total number of procedures performed (EXPno), and years of experience (EXPyears). Our outcomes were the baseline-adjusted National Institutes of Health Stroke Scale (NIHSS) score at 24-48 hours post-EVT, recanalization (extended Thrombolysis in Cerebral Infarction (eTICI) score ≥2B), and procedural duration. We used multilevel regression models with interventionists as random intercept. For EXPfreq and EXPno results were expressed per 10 procedures. RESULTS: Increased EXPfreq was associated with lower 24-48 hour NIHSS scores (adjusted (a)ß:-0.46, 95% CI -0.70 to -0.21). EXPno and EXPyears were not associated with short-term neurological outcomes. Increased EXPfreq and EXPno were both associated with recanalization (aOR=1.20, 95% CI 1.11 to 1.31 and aOR=1.08, 95% CI 1.04 to 1.12, respectively), and increased EXPfreq, EXPno, and EXPyears were all associated with shorter procedure times (aß:-3.08, 95% CI-4.32 to -1.84; aß:-1.34, 95% CI-1.84 to -0.85; and aß:-0.79, 95% CI-1.45 to -0.13, respectively). CONCLUSIONS: Higher levels of interventionist's experience are associated with better outcomes after EVT, in particular when experience is defined as the number of patients treated in the preceding year. Every 20 procedures more per year is associated with approximately one NIHSS score point decrease, an increased probability for recanalization (aOR=1.44), and a 6-minute shorter procedure time.

Penumbral imaging and functional outcome in patients with anterior circulation ischaemic stroke treated with endovascular thrombectomy versus medical therapy: a meta-analysis of individual patient-level data.

BACKGROUND: CT perfusion (CTP) and diffusion or perfusion MRI might assist patient selection for endovascular thrombectomy. We aimed to establish whether imaging assessments of irreversibly injured ischaemic core and potentially salvageable penumbra volumes were associated with functional outcome and whether they interacted with the treatment effect of endovascular thrombectomy on functional outcome. METHODS: In this systematic review and meta-analysis, the HERMES collaboration pooled patient-level data from all randomised controlled trials that compared endovascular thrombectomy (predominantly using stent retrievers) with standard medical therapy in patients with anterior circulation ischaemic stroke, published in PubMed from Jan 1, 2010, to May 31, 2017. The primary endpoint was functional outcome, assessed by the modified Rankin Scale (mRS) at 90 days after stroke. Ischaemic core was estimated, before treatment with either endovascular thrombectomy or standard medical therapy, by CTP as relative cerebral blood flow less than 30% of normal brain blood flow or by MRI as an apparent diffusion coefficient less than 620 µm2/s. Critically hypoperfused tissue was estimated as the volume of tissue with a CTP time to maximum longer than 6 s. Mismatch volume (ie, the estimated penumbral volume) was calculated as critically hypoperfused tissue volume minus ischaemic core volume. The association of ischaemic core and penumbral volumes with 90-day mRS score was analysed with multivariable logistic regression (functional independence, defined as mRS score 0-2) and ordinal logistic regression (functional improvement by at least one mRS category) in all patients and in a subset of those with more than 50% endovascular reperfusion, adjusted for baseline prognostic variables. The meta-analysis was prospectively designed by the HERMES executive committee, but not registered. FINDINGS: We identified seven studies with 1764 patients, all of which were included in the meta-analysis. CTP was available and assessable for 591 (34%) patients and diffusion MRI for 309 (18%) patients. Functional independence was worse in patients who had CTP versus those who had diffusion MRI, after adjustment for ischaemic core volume (odds ratio [OR] 0·47 [95% CI 0·30-0·72], p=0·0007), so the imaging modalities were not pooled. Increasing ischaemic core volume was associated with reduced likelihood of functional independence (CTP OR 0·77 [0·69-0·86] per 10 mL, pinteraction=0·29; diffusion MRI OR 0·87 [0·81-0·94] per 10 mL, pinteraction=0·94). Mismatch volume, examined only in the CTP group because of the small numbers of patients who had perfusion MRI, was not associated with either functional independence or functional improvement. In patients with CTP with more than 50% endovascular reperfusion (n=186), age, ischaemic core volume, and imaging-to-reperfusion time were independently associated with functional improvement. Risk of bias between studies was generally low. INTERPRETATION: Estimated ischaemic core volume was independently associated with functional independence and functional improvement but did not modify the treatment benefit of endovascular thrombectomy over standard medical therapy for improved functional outcome. Combining ischaemic core volume with age and expected imaging-to-reperfusion time will improve assessment of prognosis and might inform endovascular thrombectomy treatment decisions. FUNDING: Medtronic.

Dystonic Head Tremor and the Coexistence of Headache.

Background: Head tremor may be observed in the presence of cervical dystonia and sometimes coexists with headache. We wished to investigate the presence of headache in dystonic head tremor. Methods: We studied the files of 19 patients from our outpatient clinic (1997-2017) with dystonic head tremor and assessed the co-occurrence of headache. We also performed a literature search of the topic. Results: Cervicogenic headache was present in nearly 37% of patients with dystonic head tremor. More than 85% of our patients presented with a "no-no" head tremor. Discussion: Headache is common in dystonic head tremor. Cervicogenic headache seems to be more frequent in patients with dystonic head tremor than in the general population. Future studies should compare the presence of cervicogenic headache in essential head tremor patients with that in patients suffering from dystonic head tremor.

Endovascular thrombectomy in patients with acute ischaemic stroke and atrial fibrillation: a MR CLEAN subgroup analysis.

AIMS: Endovascular thrombectomy (EVT) improves outcome after acute ischaemic stroke (AIS) caused by an intracranial occlusion. The aim of the present study was to determine whether atrial fibrillation (AF) modifies the effect of EVT. METHODS AND RESULTS: MR CLEAN was a randomised clinical trial of EVT plus usual care vs. usual care alone for patients with an intracranial occlusion. The primary outcome was the modified Rankin scale (mRS) score at 90 days. The primary effect parameter was the adjusted common odds ratio (acOR), estimated with ordinal logistic regression and adjusted for age and stroke severity at baseline. Treatment effect modification by AF was assessed using a multiplicative interaction variable. We included all 500 patients. In total, 135 (27%) had AF. These patients were older, had a worse pre-stroke mRS score and were less often treated with IV alteplase. In patients without AF, the estimated treatment effect was similar to the overall treatment effect (acOR 1.9, 95% CI: 1.3 to 2.7). In patients with AF, the treatment effect appeared lower (acOR 1.0, 95% CI: 0.6 to 1.9). The interaction of treatment effect and AF was not significant (p=0.09, after adjustment p=0.12). CONCLUSIONS: This study did not show significant difference in the EVT effect between acute stroke patients with and those without AF.

The relationship between interventionists' experience and clinical and radiological outcome in intra-arterial treatment for acute ischemic stroke. A MR CLEAN pretrial survey.

BACKGROUND: Intra-arterial treatment in acute ischemic stroke is safe and effective as recently shown in several randomized clinical trials. The level of experience of the interventionist performing the IAT procedure has not been studied. The present study investigates effects of interventionists' experience on technical aspects of the procedure and clinical outcome of the patient. METHODS: In this study of 313 patients with a proximal intracranial arterial anterior circulation occlusion, treated in the Netherlands from 2002 until participation in the Multicenter Randomized Clinical trial of Endovascular treatment for acute ischemic stroke (MR CLEAN), data were collected retrospectively. The association of the senior interventionists' experience with duration of the procedure, adverse events, recanalization, neurological outcome, and functional outcome at discharge was analyzed. Multiple regression models adjusted for age, sex, stroke severity, carotid terminus occlusion, use of a retrievable stent and onset to door time were used. RESULTS: No association between interventionists' experience and recanalization, neurological outcome, or functional outcome was observed in a strict selection of patients. This strict selection include a start of intra-arterial treatment within 6h, no coagulation disturbances, systolic blood pressure<185mmHg and diastolic blood pressure<110mmHg), blood glucose level between 2.7 and 22.2mmol/L and the existence of a proximal intracranial occlusion. However, significant shorter procedure times were found with more experienced interventionists' [adjusted beta coefficient -0.67, 95% CI: -1.24 to -0.11], when using less strict inclusion criteria. CONCLUSION: No significant relation between the level of experience and either serious neurologic adverse events or poor outcomes was observed in this study of treatments by interventionists with experience of <50 previous procedures. We need further research to explore the relation of much higher levels of interventionists' and team experience with procedure times, results and patient outcomes.

Quality of life after intra-arterial treatment for acute ischemic stroke in the MR CLEAN trial-Update.

Background Health-related quality of life measured with the EuroQol Group 5-Dimension Self-Report Questionnaire was one of the secondary outcomes in the Multicenter Randomized Clinical trial of Endovascular treatment for Acute ischemic stroke in the Netherlands (MR CLEAN). We reported no statistically significant difference in EuroQol Group 5-Dimension Self-Report Questionnaire score between the intervention and control groups, but deaths were not included. Aims Reanalyze the effect of intra-arterial treatment for large vessel occlusion in acute ischemic stroke patients on health-related quality of life in more detail. We now include patients who died during follow-up. Methods The EuroQol Group 5-Dimension Self-Report Questionnaire questionnaires were obtained 90 days after treatment. We used the Dutch tariff to derive a utility index from the EuroQol Group 5-Dimension Self-Report Questionnaire score. Treatment effect was estimated with the Mann-Whitney U test and linear regression. The effect of treatment on the distribution of EuroQol Group 5-Dimension Self-Report Questionnaire dimension scores was assessed with ordinal logistic regression. Results We obtained EuroQol Group 5-Dimension Self-Report Questionnaire scores from 457 (91.7%) of the 500 patients, including 108 who died before follow-up. Median EuroQol Group 5-Dimension Self-Report Questionnaire score in the intervention group was 0.57, and 0.39 in the control group (p = 0.03). Treatment effect estimated with linear regression was 0.07 (95%CI: -0.001 to 0.143). Treatment specifically affected EuroQol Group 5-Dimension Self-Report Questionnaire dimensions "mobility" (OR: 0.43, 95%CI: 0.29-0.66), "self-care" (OR: 0.60, 95%CI: 0.41-0.89), and "usual activities" (OR: 0.53, 95%CI: 0.36-0.79). Conclusion Treatment had a limited effect on quality of life, as measured with the EuroQol Group 5-Dimension Self-Report Questionnaire. Nevertheless, patients with acute ischemic stroke caused by an intracranial occlusion in the anterior circulation, who had intra-arterial treatment, experience better health-related quality of life than patients without intra-arterial treatment. Trial Registration URL: http://www.isrctn.com/ISRCTN10888758 Unique identifier: ISRCTN10888758.