Puck S.S. Fransen

Time to Treatment With Endovascular Thrombectomy and Outcomes From Ischemic Stroke: A Meta-analysis

IMPORTANCE Endovascular thrombectomy with second-generation devices is beneficial for patients with ischemic stroke due to intracranial large-vessel occlusions. Delineation of the association of treatment time with outcomes would help to guide implementation. OBJECTIVE To characterize the period in which endovascular thrombectomy is associated with benefit, and the extent to which treatment delay is related to functional outcomes, mortality, and symptomatic intracranial hemorrhage. DESIGN, SETTING, AND PATIENTS Demographic, clinical, and brain imaging data as well as functional and radiologic outcomes were pooled from randomized phase 3 trials involving stent retrievers or other second-generation devices in a peer-reviewed publication (by July 1, 2016). The identified 5 trials enrolled patients at 89 international sites. EXPOSURES Endovascular thrombectomy plus medical therapy vs medical therapy alone; time to treatment. MAIN OUTCOMES AND MEASURES The primary outcome was degree of disability (mRS range, 0-6; lower scores indicating less disability) at 3 months, analyzed with the common odds ratio (cOR) to detect ordinal shift in the distribution of disability over the range of the mRS; secondary outcomes included functional independence at 3 months, mortality by 3 months, and symptomatic hemorrhagic transformation. RESULTS Among all 1287 patients (endovascular thrombectomy + medical therapy [n = 634]; medical therapy alone [n = 653]) enrolled in the 5 trials (mean age, 66.5 years [SD, 13.1]; women, 47.0%), time from symptom onset to randomization was 196 minutes (IQR, 142 to 267). Among the endovascular group, symptom onset to arterial puncture was 238 minutes (IQR, 180 to 302) and symptom onset to reperfusion was 286 minutes (IQR, 215 to 363). At 90 days, the mean mRS score was 2.9 (95% CI, 2.7 to 3.1) in the endovascular group and 3.6 (95% CI, 3.5 to 3.8) in the medical therapy group. The odds of better disability outcomes at 90 days (mRS scale distribution) with the endovascular group declined with longer time from symptom onset to arterial puncture: cOR at 3 hours, 2.79 (95% CI, 1.96 to 3.98), absolute risk difference (ARD) for lower disability scores, 39.2%; cOR at 6 hours, 1.98 (95% CI, 1.30 to 3.00), ARD, 30.2%; cOR at 8 hours,1.57 (95% CI, 0.86 to 2.88), ARD, 15.7%; retaining statistical significance through 7 hours and 18 minutes. Among 390 patients who achieved substantial reperfusion with endovascular thrombectomy, each 1-hour delay to reperfusion was associated with a less favorable degree of disability (cOR, 0.84 [95% CI, 0.76 to 0.93]; ARD, -6.7%) and less functional independence (OR, 0.81 [95% CI, 0.71 to 0.92], ARD, -5.2% [95% CI, -8.3% to -2.1%]), but no change in mortality (OR, 1.12 [95% CI, 0.93 to 1.34]; ARD, 1.5% [95% CI, -0.9% to 4.2%]). CONCLUSIONS AND RELEVANCE In this individual patient data meta-analysis of patients with large-vessel ischemic stroke, earlier treatment with endovascular thrombectomy + medical therapy compared with medical therapy alone was associated with lower degrees of disability at 3 months. Benefit became nonsignificant after 7.3 hours.

Time to Reperfusion and Treatment Effect for Acute Ischemic Stroke: A Randomized Clinical Trial

IMPORTANCE Intra-arterial treatment (IAT) for acute ischemic stroke caused by intracranial arterial occlusion leads to improved functional outcome in patients treated within 6 hours after onset. The influence of treatment delay on treatment effect is not yet known. OBJECTIVE To evaluate the influence of time from stroke onset to the start of treatment and from stroke onset to reperfusion on the effect of IAT. DESIGN, SETTING, AND PARTICIPANTS The Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN) was a multicenter, randomized clinical open-label trial of IAT vs no IAT in 500 patients. The time to the start of treatment was defined as the time from onset of symptoms to groin puncture (TOG). The time from onset of treatment to reperfusion (TOR) was defined as the time to reopening the vessel occlusion or the end of the procedure in cases for which reperfusion was not achieved. Data were collected from December 3, 2010, to June 3, 2014, and analyzed (intention to treat) from July 1, 2014, to September 19, 2015. MAIN OUTCOMES AND MEASURES Main outcome was the modified Rankin Scale (mRS) score for functional outcome (range, 0 [no symptoms] to 6 [death]). Multiple ordinal logistic regression analysis estimated the effect of treatment and tested for the interaction of time to randomization, TOG, and TOR with treatment. The effect of treatment as a risk difference on reaching independence (mRS score, 0-2) was computed as a function of TOG and TOR. Calculations were adjusted for age, National Institutes of Health Stroke Scale score, previous stroke, atrial fibrillation, diabetes mellitus, and intracranial arterial terminus occlusion. RESULTS Among 500 patients (58% male; median age, 67 years), the median TOG was 260 (interquartile range [IQR], 210-311) minutes; median TOR, 340 (IQR, 274-395) minutes. An interaction between TOR and treatment (P = .04) existed, but not between TOG and treatment (P = .26). The adjusted risk difference (95% CI) was 25.9% (8.3%-44.4%) when reperfusion was reached at 3 hours, 18.8% (6.6%-32.6%) at 4 hours, and 6.7% (0.4%-14.5%) at 6 hours. CONCLUSION AND RELEVANCE For every hour of reperfusion delay, the initially large benefit of IAT decreases; the absolute risk difference for a good outcome is reduced by 6% per hour of delay. Patients with acute ischemic stroke require immediate diagnostic workup and IAT in case of intracranial arterial vessel occlusion. TRIAL REGISTRATION trialregister.nl Identifier: NTR1804.

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.

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 anesthetic management during intra-arterial therapy for acute stroke in MR CLEAN.

Background: The aim of the current study was to assess the influence of anesthetic management on the effect of treatment in the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN). Methods: MR CLEAN was a multicenter, randomized, open-label trial of intra-arterial therapy (IAT) vs no IAT. The intended anesthetic management at the start of the procedure was used for this post hoc analysis. The primary effect parameter was the adjusted common odds ratio (acOR) for a shift in direction of a better outcome on the modified Rankin Scale (mRS) at 90 days, estimated with multivariable ordinal logistic regression analysis, which included a term for general anesthesia (GA). Results: GA was associated with significant (p = 0.011) effect modification, resulting in estimated decrease of 51% (95% confidence interval [CI] 31%–86%) in treatment effect compared to non-GA. We found a shift in the distribution on the mRS in favor of non-GA compared to control group (acOR 2.18 [95% CI 1.49–3.20]). The shift in distribution between GA and control group was in a similar direction (acOR 1.12 [95% CI 0.71–1.78]) with loss of statistical significance. Conclusions: In this post hoc analysis, we found that the type of anesthetic management influences outcome following IAT. Only treatment without general anesthesia was associated with a significant treatment benefit in MR CLEAN. Classification of evidence: This study provides Class II evidence that for patients with acute ischemic stroke undergoing IAT, mRS scores at 90 days improve only in patients treated without GA.

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.)

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.

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 &khgr;2 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.

Treatment in patients who are not eligible for intravenous alteplase: MR CLEAN subgroup analysis

Background and purpose Patients with acute ischemic stroke due to intracranial large vessel occlusion benefit from intra-arterial therapy. Uncertainty exists about the effect of intra-arterial therapy in patients with contraindications for treatment with intravenous alteplase treatment. Our aim was to describe the clinical characteristics of this subgroup of patients and whether intra-arterial therapy is as safe and effective as it is after intravenous alteplase treatment. Methods All 500 MR CLEAN patients were included and we distinguished between patients who were and were not treated with intravenous alteplase treatment. We estimated the effect of intra-arterial therapy on the shift on the modified Rankin Scale score with ordinal logistic regression analysis and tested for interaction of intravenous alteplase treatment with intra-arterial therapy on outcome. Furthermore, safety parameters and serious adverse events were analyzed. Results Fifty-five patients (11%) were not treated with intravenous alteplase treatment, mostly because of prolonged coagulation time tests or recent surgery. These patients were older and more often had atrial fibrillation or other vascular comorbidity. There was no interaction between intravenous alteplase treatment and intervention effect (p = 0.927). Intra-arterial therapy effect size in patients without intravenous alteplase treatment was 2.06 [95% CI: 0.69–6.13] and in patients with intravenous alteplase treatment 1.71 [95% CI: 1.22–2.40]. There were no safety issues. Conclusions For patients with acute ischemic anterior circulation stroke caused by intracranial large vessel occlusion, who have contraindications for intravenous alteplase, intra-arterial treatment is not less effective or less safe than in patients who receive the treatment after intravenous alteplase. Clinical trial registration Clinical trial registration-URL: http://www.trialregister.nl. Unique identifier: (NTR)1804. Clinical trial registration-URL: http://www.controlled-trials.com. Unique identifier: ISRCTN10888758.