***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background and Purpose — Endovascular therapy in addition to st and ard care ( EVT+SC ) has been demonstrated to be more effective than SC in acute ischemic large vessel occlusion stroke . Our aim was to determine the cost-effectiveness of EVT+SC depending on patients ’ initial National Institutes of Health Stroke Scale ( NIHSS ) score , time from symptom onset , Alberta Stroke Program Early CT Score ( ASPECTS ) , and occlusion location . Methods — A decision model based on Markov simulations estimated lifetime costs and quality -adjusted life years ( QALYs ) associated with both strategies applied in a US setting . Model input parameters were obtained from the literature , including recently pooled outcome data of 5 r and omized controlled trials ( ESCAPE [ Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke ] , EXTEND-IA [ Extending the Time for Thrombolysis in Emergency Neurological Deficits – Intra-Arterial ] , MR CLEAN [ Multicenter R and omized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherl and s ] , REVASCAT [ R and omized Trial of Revascularization With Solitaire FR Device Versus Best Medical Therapy in the Treatment of Acute Stroke Due to Anterior Circulation Large Vessel Occlusion Presenting Within 8 Hours of Symptom Onset ] , and SWIFT PRIME [ Solitaire With the Intention for Thrombectomy as Primary Endovascular Treatment ] ) . Probabilistic sensitivity analysis was performed to estimate uncertainty of the model results . Net monetary benefits , incremental costs , incremental effectiveness , and incremental cost-effectiveness ratios were derived from the probabilistic sensitivity analysis . The willingness-to-pay was set to $ 50 000/QALY . Results — Overall , EVT+SC  was cost-effective compared with SC ( incremental cost : $ 4938 , incremental effectiveness : 1.59 QALYs , and incremental cost-effectiveness ratio : $ 3110/QALY ) in 100 % of simulations . In all patient subgroups , EVT+SC led to gained QALYs ( range : 0.47–2.12 ) , and mean incremental cost-effectiveness ratios were considered cost-effective . However , subgroups with ASPECTS ⩽5 or with M2 occlusions showed considerably higher incremental cost-effectiveness ratios ( $ 14 273/QALY and $ 28 812/QALY , respectively ) and only reached suboptimal acceptability in the probabilistic sensitivity analysis ( 75.5 % and 59.4 % , respectively ) . All other subgroups had acceptability rates of 90 % to 100 % . Conclusions — EVT+SC is cost-effective in most subgroups . In patients with ASPECTS ⩽5 or with M2 occlusions , cost-effectiveness remains uncertain based on current data Background and Purpose — Mechanical thrombectomy has the potential to improve recanalization rates and outcomes for patients with ischemic stroke , but potential gains could be offset by procedural complications and costs . We evaluated the cost and utility of combined intravenous ( IV ) tissue-type plasminogen activator ( tPA ) and mechanical thrombectomy compared to IV tPA alone for acute large-vessel ischemic stroke . Methods — We constructed a decision tree for a hypothetical 68-year-old with a large-vessel ischemic stroke who is eligible for IV tPA . The interventional strategy was IV tPA , a cerebral angiogram , and mechanical thrombectomy and thrombolysis if indicated . Recanalization , hemorrhage complications , and outcomes for the interventional strategy were from the Multi-MERCI study . The medical strategy was IV tPA using inputs from a comprehensive systematic review . Costs were estimated from Medicare reimbursements . We modeled lifetime costs and utilities for disability using a Markov model and Monte-Carlo multivariable sensitivity analysis . Results — For the baseline scenario , the recanalization rate was 72.9 % for the interventional strategy and 46.2 % for the medical strategy . For the interventional strategy , the symptomatic hemorrhage rate was 8.6 % with recanalization and 15.4 % without . For the medical strategy , the corresponding rates were 3.6 % and 13.3 % , respectively . The interventional strategy was cost-effective in 97.6 % of simulations ( incremental cost-effectiveness ratio $ 16 001/ quality -adjusted life year ; 95 % CI , $ 2736–$39 232 ) . Conclusions — Based on observational data , the combination of IV tPA and mechanical thrombectomy for large-vessel ischemic stroke appears to be cost-effective compared to IV tPA alone . These findings require additional validation with r and omized trial data Background and Purpose — The only Food and Drug Administration ( FDA ) -approved treatment for acute ischemic stroke is tissue plasminogen activator ( tPA ) given intravenously within 3 hours of symptom onset . An alternative strategy for opening intracranial vessels during stroke is mechanical embolectomy , especially for patients ineligible for intravenous tPA .  Methods — We investigated the safety and efficacy of a novel embolectomy device ( Merci Retriever ) to open occluded intracranial large vessels within 8 hours of the onset of stroke symptoms in a prospect i ve , nonr and omized , multicenter trial . All patients were ineligible for intravenous tPA .  Primary outcomes were recanalization and safety , and secondary outcomes were neurological outcome at 90 days in recanalized versus nonrecanalized patients . Results — Recanalization was achieved in 46 % ( 69/151 ) of patients on intention to treat analysis , and in 48 % ( 68/141 ) of patients in whom the device was deployed . This rate is significantly higher than that expected using an historical control of 18 % ( P<0.0001 ) . Clinical ly significant procedural complications occurred in 10 of 141 ( 7.1 % ) patients . Symptomatic intracranial hemorrhages was observed in 11 of 141 ( 7.8 % ) patients . Good neurological outcomes ( modified Rankin score ≤2 ) were more frequent at 90 days in patients with successful recanalization compared with patients with unsuccessful recanalization ( 46 % versus 10 % ; relative risk [ RR ] , 4.4 ; 95 % CI , 2.1 to 9.3 ; P<0.0001 ) , and mortality was less ( 32 % versus 54 % ; RR , 0.59 ; 95 % CI , 0.39 to 0.89 ; P=0.01 ) . Conclusions — A novel endovascular embolectomy device can significantly restore vascular patency during acute ischemic stroke within 8 hours of stroke symptom onset and provides an alternative intervention for patients who are otherwise ineligible for thrombolytics Background and Purpose — Endovascular mechanical thrombectomy may be used during acute ischemic stroke due to large vessel intracranial occlusion . First-generation MERCI devices achieved recanalization rates of 48 % and , when coupled with intraarterial thrombolytic drugs , recanalization rates of 60 % have been reported . Enhancements in embolectomy device design may improve recanalization rates . Methods — Multi MERCI was an international , multicenter , prospect i ve , single-arm trial of  thrombectomy in patients with large vessel stroke treated within 8 hours of symptom onset . Patients with persistent large vessel occlusion after IV tissue plasminogen activator treatment were included . Once the newer generation ( L5 Retriever ) device became available , investigators were instructed to use the L5 Retriever to open vessels and could subsequently use older generation devices and /or intraarterial tissue plasminogen activator . Primary outcome was recanalization of the target vessel . Results — One hundred sixty-four patients received thrombectomy  and 131 were initially treated with the L5 Retriever .  Mean age±SD was 68±16 years , and baseline median ( interquartile range ) National Institutes of Health Stroke Scale score was 19 ( 15 to 23 ) . Treatment with the L5 Retriever result ed in successful recanalization in 75 of 131 ( 57.3 % ) treatable vessels and in 91 of 131 ( 69.5 % ) after adjunctive therapy ( intraarterial tissue plasminogen activator , mechanical ) . Overall , favorable clinical outcomes ( modified Rankin Scale 0 to 2 ) occurred in 36 % and mortality was 34 % ; both outcomes were significantly related to vascular recanalization . Symptomatic intracerebral hemorrhage occurred in 16 patients ( 9.8 % ) ; 4 ( 2.4 % ) of these were parenchymal hematoma type II . Clinical ly significant procedural complications occurred in 9 ( 5.5 % ) patients . Conclusions — Higher rates of recanalization were associated with a newer generation thrombectomy device compared with first-generation devices , but these differences did not achieve statistical significance . Mortality trended lower and the proportion of good clinical outcomes trended higher , consistent with better recanalization BACKGROUND AND PURPOSE We assessed the influence of functional status at 6 months after ischemic stroke on cause of death during long-term follow-up in 3 prospect i ve cohorts . METHODS The cohorts were 7710 patients from the Oxfordshire Community Stroke Project , Lothian Stroke Register , and International Stroke Trial .  Functional status was assessed at 6 months after stroke onset . Causes of death were identified from death certificates , and were also classified into " stroke-related " or " other " causes . We calculated the relative risk with 95 % CI to assess the association between dependency level and cause of death . We also performed a multivariable regression analysis to adjust for other relevant factors . RESULTS Six months after stroke onset 5961 ( 78 % ) patients were still alive . At the end of follow-up period , 1620 ( 47 % ) patients who were functionally dependent at 6 months after stroke onset had died vs 711 ( 28 % ) independent patients . Dependent patients had a relative risk of dying from stroke of 1.70 ( 95 % CI , 1.44 - 2.00 ) compared to independent patients . Overall , dependent patients had a relative risk of 1.68 ( 95 % CI , 1.49 - 1.91 ) of dying from stroke-related causes . Dependency remained significantly ( P<0.01 ) associated with stroke-related causes of death in a multivariable regression analysis . CONCLUSIONS Stroke-related deaths continue to be a problem during the years after an ischemic stroke , especially in patients who are functionally dependent at 6 months after onset . Better acute treatments to reduce dependency and adequate secondary prevention remain high priorities BACKGROUND Trials of endovascular therapy for ischemic stroke have produced variable results . We conducted this study to test whether more advanced imaging selection , recently developed devices , and earlier intervention improve outcomes . METHODS We r and omly assigned patients with ischemic stroke who were receiving 0.9 mg of alteplase per kilogram of body weight less than 4.5 hours after the onset of ischemic stroke either to undergo endovascular thrombectomy with the Solitaire FR ( Flow Restoration ) stent retriever or to continue receiving alteplase alone .  All the patients had occlusion of the internal carotid or middle cerebral artery and evidence of salvageable brain tissue and ischemic core of less than 70 ml on computed tomographic ( CT ) perfusion imaging . The co primary outcomes were reperfusion at 24 hours and early neurologic improvement ( ≥8-point reduction on the National Institutes of Health Stroke Scale or a score of 0 or 1 at day 3 ) . Secondary outcomes included the functional score on the modified Rankin scale at 90 days . RESULTS The trial was stopped early because of efficacy after 70 patients had undergone r and omization ( 35 patients in each group ) . The percentage of ischemic territory that had undergone reperfusion at 24 hours was greater in the endovascular-therapy group than in the alteplase-only group ( median , 100 % vs. 37 % ; P<0.001 ) . Endovascular therapy , initiated at a median of 210 minutes after the onset of stroke , increased early neurologic improvement at 3 days ( 80 % vs. 37 % , P=0.002 ) and improved the functional outcome at 90 days , with more patients achieving functional independence ( score of 0 to 2 on the modified Rankin scale , 71 % vs. 40 % ; P=0.01 ) . There were no significant differences in rates of death or symptomatic intracerebral hemorrhage . CONCLUSIONS In patients with ischemic stroke with a proximal cerebral arterial occlusion and salvageable tissue on CT perfusion imaging , early thrombectomy with the Solitaire FR stent retriever , as compared with alteplase alone , improved reperfusion , early neurologic recovery , and functional outcome . ( Funded by the Australian National Health and Medical Research Council and others ; EXTEND-IA Clinical Trials.gov number , NCT01492725 , and Australian New Zeal and Clinical Trials Registry number , ACTRN12611000969965 . ) Objective : To evaluate the cost-effectiveness of adding endovascular thrombectomy to st and ard care in patients with acute ischemic stroke . Methods : The cost-effectiveness analysis of endovascular thrombectomy in patients with acute is 
    Output:
    
Conclusions — There is a robust body of evidence for the cost and cost-effectiveness of EVT .
The cost analyses suggested that although EVT was associated with higher costs , it also result ed in improved patient outcomes .
From the cost-effectiveness studies , EVT seems to be good value for money when a threshold of $ 50 000 per quality -adjusted life year gained is adopted