***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 
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    Input: Background — Thrombolytic therapy with intravenous alteplase within 4.5 hours of ischemic stroke onset increases the overall likelihood of an excellent outcome ( no , or nondisabling , symptoms ) . Any improvement in functional outcome distribution has value , and herein we provide an assessment of the effect of alteplase on the distribution of the functional level by treatment delay , age , and stroke severity . Methods — Prespecified pooled analysis of 6756 patients from 9 r and omized trials comparing alteplase versus placebo/open control . Ordinal logistic regression models assessed treatment differences after adjustment for treatment delay , age , stroke severity , and relevant interaction term(s ) . Results — Treatment with alteplase was beneficial for a delay in treatment extending to 4.5 hours after stroke onset , with a greater benefit with earlier treatment . Neither age nor stroke severity significantly influenced the slope of the relationship between benefit and time to treatment initiation . For the observed case mix of patients treated within 4.5 hours of stroke onset ( mean 3 hours and 20 minutes ) , the net absolute benefit from alteplase ( ie , the difference between those who would do better if given alteplase and those who would do worse ) was 55 patients per 1000 treated ( 95 % confidence interval , 13–91 ; P=0.004 ) . Conclusions — Treatment with intravenous alteplase initiated within 4.5 hours of stroke onset increases the chance of achieving an improved level of function for all patients across the age spectrum , including the over 80s and across all severities of stroke studied ( top versus bottom fifth means : 22 versus 4 ) ; the earlier that treatment is initiated , the greater the benefit Objectives Acute Recanalization of Thrombo-Embolic Ischemic Stroke with pREset ( ARTESp ) is a prospect i ve multicenter study assessing the efficacy and safety of the pREset stent retriever for the treatment of intracranial vessel occlusion . Determination of the effect of transfer status on clinical outcome was a secondary objective . Methods Efficacy was measured by recanalization success ( Thrombolysis in Cerebral Infa rct ion score ≥2b ) and favorable clinical outcome at 90 days ( modified Rankin Scale 0–2 ) . Intracranial hemorrhage ( ICH ) and death at 90 days were safety measures . The outcome of directly admitted ( DAP ) and transferred ( TP ) patients was investigated using multivariable regression models . Results Four study centers included 100 patients ( mean age 68.3 years , median National Institutes of Health Stroke Scale score 15 ) . Recanalization success was achieved in 84.4 % after a mean of 1.7 passes . ICH was detected in 14.0 % , with 2.0 % being symptomatic . At 90 days , 62.5 % of the patients had a favorable outcome and 7.3 % died . TP had longer occlusion times ( 289 vs 180 minutes , p<0.001 ) and a lower rate of favorable outcome ( 58.0 % vs 78.4 % , p=0.046 ) than DAP . Multivariable regression revealed occlusion time as the critical determinant ( OR=0.963 , 95 % CI 0.931 to 0.997 , p=0.032 ) , whereas transfer status itself showed no significant association ( OR=0.565 , CI 0.133 to 2.393 , p=0.438 ) . Conclusions pREset proved to be safe and effective for the treatment of acute intracranial vessel occlusion . Increased occlusion time impaired clinical outcome in TP . Trial registration number NCT02437409 ; Results Importance Intravenous thrombolysis ( IVT ) followed by mechanical thrombectomy ( MT ) is recommended to treat acute ischemic stroke ( AIS ) with a large vessel occlusion ( LVO ) . Most hospitals do not have on-site MT facilities , and most patients need to be transferred secondarily after IVT ( drip and ship ) , which may have an effect on the neurologic outcome . Objective To compare the functional independence at 3 months between patients treated under the drip- and -ship paradigm and those treated on site ( mothership ) . Design , Setting , and Participants This study used a prospect ively gathered registry of patients with AIS to select patients admitted through the Saint-Antoine and Tenon ( drip and ship ) or the Fondation Rothschild ( mothership ) hospitals from January 1 , 2013 , through April 30 , 2016 . The study included patients older than 18 years treated with bridging therapy for AIS with LVO of the anterior circulation . Among the 159 patients who received MT at the mothership , 100 had been transferred after IVT  from the drip- and -ship hospitals and 59 had received IVT on site . Main Outcomes and Measures The main outcome was 3-month functional independence ( modified Rankin scale score ⩽2 ) . Both groups were compared using a multivariate linear model , including variables that were significantly different in the 2 groups . Results During the study period , 497 patients were hospitalized at the drip- and -ship and mothership hospitals for an AIS eligible to reperfusion therapy ; 11 patients had a basilar artery occlusion and were excluded , leaving 100 patients in the drip- and -ship group ( mean age , 73 years ; age range , 60 - 81 years ; 57 men [ 57.0 % ] ) and 59 in the mothership group ( mean age , 70 years ; age range , 58 - 82 years ; 29 men [ 49.2 % ] ) . The proportion of patients with a favorable neurologic outcome at 3 months was similar in both groups ( drip and ship , 61 [ 61.0 % ] ; mothership , 30 [ 50.8 % ] ; P = .26 ) , even after adjusting the analysis for the baseline National Institutes of Health Stroke Scale score , diffusion-weighted imaging Alberta Stroke Program Early Computed Tomography Score , and general anesthesia ( P = .82 ) . Patients had less severe conditions in the drip- and -ship group ( median baseline National Institutes of Health Stroke Scale score , 15 vs 17 [ P = .03 ] ; median diffusion-weighted imaging Alberta Stroke Program Early Computed Tomography Score , 7.5 vs 7 [ P = .05 ] ) . Process times were longer in the drip- and -ship group ( onset-to-needle time , 150 vs 135 minutes ; onset-to-puncture time , 248 vs 189 minutes ; and onset-to-recanalization time , 297 vs 240 minutes ; P < .001 ) . Both groups were similar in terms of substantial recanalization ( Thrombolysis in Cerebral Ischemia scores 2B to 3 ; drip and ship , 84 [ 84.0 % ] ; mothership , 47 [ 79.7 % ] ; P = .49 ) and symptomatic hemorrhagic transformation ( drip and ship , 2 [ 2.0 % ] ; mothership , 2 [ 3.4 % ] ; P = .63 ) . Conclusions and Relevance This study found that patients treated under the drip- and -ship paradigm also benefit from bridging therapy , with no statistically significant difference compared with those treated directly in a comprehensive stroke center The outcome of ischemic stroke is related to the volume of brain that is infa rct ed , and the volume of infa rct ion is directly related to the time to reperfusion.1 In an anterior circulation , large-vessel ischemic stroke 1.9 million neurons are lost every minute.2 Treatment efficacy is dependent on time to treatment initiation . Acute ischemic stroke is treated medically with the administration of intravenous alteplase . Recent results of several r and omized trials established the efficacy of endovascular treatment in ischemic stroke.3–8 The facilities and expertise needed for endovascular procedures are only available at endovascular capable centers ( ECCs ) , which are typically tertiary care hospitals . Medical treatment with alteplase is more widely available . This creates 2 options for prehospital destination decision-making for suspected stroke : ( 1 ) transport the patient directly to the nearest ECC to receive alteplase and , if appropriate , immediate endovascular therapy even though this might mean bypassing a closer non-ECC ( nECC ; mothership model ) ; or ( 2 ) transport the patient to the nearest nECC to receive alteplase and then transfer the patient to the nearest ECC for endovascular therapy ( drip and ship model ) . There are advantages and disadvantages to each of these options , and it is currently unknown which of these options will lead to the highest probability of good outcome for the patient . The RACECAT trial in Barcelona , Spain , is planned to directly address this question ( NCT02795962 ) . Herein , we propose a methodology for addressing this problem using statistical probability modeling and suggest a c and i date model for evaluation . # # # Assumptions We make several assumptions in the development of the prediction models ( Table I in the online-only Data Supplement ) . First , these models apply when there is uncertainty on which transport and treatment decision to choose . Second , the nECC is the closest treatment center to the location of stroke occurrence . If an ECC is the Background and Purpose — Although successful reperfusion is usually defined as a modified Thrombolysis in Cerebral Infa rct ion ( mTICI ) 2B or 3 at the end of the procedure , studies have shown that mTICI 2B patients had poorer functional outcomes than TICI 3 patients . An mTICI 2C category has been recently introduced for patients with near-complete perfusion except for slow flow in a few distal cortical vessels or presence of small distal cortical emboli after mechanical thrombectomy . The purpose of this study was to evaluate the difference in functional outcome between patients achieving successful reperfusion ( ie , mTICI 2B , mTICI 2C , and TICI 3 scores ) . Methods — Ancillary study from the ASTER ( Contact Aspiration Versus Stent Retriever for Successful Revascularization ) prospect i ve multicenter blinded end point trial . Reperfusion results are reported as the mTICI score , including the mTICI 2C grade . Primary outcome was the percentage of patients with favorable outcome defined as a 90-day modified Rankin Scale score of 0 to 2 . Results — Two hundred ninety patients with successful reperfusion ( mTICI ≥2B ) , harboring ischemic stroke secondary to occlusion of the anterior circulation within 6 hours of onset of symptoms , undergoing mechanical thrombectomy by contact aspiration or stent retriever were included . Favorable outcome ( pre-specified as primary outcome of this ancillary study ) did not differ significantly between the 3 reperfusion grade s , with a similar positive effect of 2C ( odds ratio , 1.71 ; 95 % confidence interval , 0.98–3.00 ) and 3 ( odds ratio , 1.73 ; 95 % confidence interval , 0.88–3.41 ) grade s compared with 2B grade . After combining grade s 2C and 3 , patients had a significantly higher rate of favorable outcome than patients with 2B ( odds ratio , 1.72 ; 95 % confidence interval , 1.01–2.90 ; P=0.043 ) . Favorable outcome rate decreased with increasing onset-to-reperfusion time , with no significant interaction between mTICI 2C/3 grade and onset-to-reperfusion time on favorable outcome . Conclusions — Combining mTICI 2C and TICI 3 grade s helps to determine a subgroup of patients achieving better functional outcomes than mTICI 2B patients . Achieving mTICI 2C/3 reperfusion should be the new aim of mechanical thrombectomy for anterior circulation LVO BACKGROUND Among patients with acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation , less than 40 % regain functional independence when treated with intravenous tissue plasminogen activator ( t-PA ) alone . Thrombectomy with the use of a stent retriever , in addition to intravenous t-PA , increases reperfusion rates and may improve long-term functional outcome . METHODS We r and omly assigned eligible patients with stroke who were receiving or had received intravenous t-PA to continue with t-PA alone ( control group ) or to undergo endovascular thrombectomy with the use of a stent retriever within 6 hours after symptom onset  ( intervention group ) . Patients had confirmed occlusions in the proximal anterior intracranial circulation and an absence of large ischemic-core lesions . The primary outcome was the severity of global disability at 90 days , as assessed by means of the modified Rankin scale ( with scores ranging from 0 [ no symptoms ] to 6 [ death ] ) . RESULTS The study was stopped early because of efficacy . At 39 centers , 196 patients underwent r and omization ( 98 patients in each group ) . In the intervention group , the median time from qualifying imaging to groin puncture was 57 minutes , and the rate of substantial reperfusion at the end of the procedure was 88 % . Thrombectomy with the stent retriever plus intravenous t-PA  reduced disability at 90 days over the entire range of scores on the modified Rankin scale ( P<0.001 ) . The rate of functional independence ( modified Rankin scale score , 0 to 2 ) was higher in the intervention group than in the control group ( 60 % vs. 35 % , P<0.001 ) . There were no significant between-group differences in 90-day mortality ( 9 % vs. 12 % , P=0.50 ) or symptomatic intracranial hem 
    Output:
    
Conclusions Patients who had an acute ischemic stroke admitted directly to a comprehensive stroke center ( MS patients ) with endovascular capacities may have better 90-day outcomes than those receiving DS treatment .