Clinical and Neuroimaging Outcomes of Direct Thrombectomy vs Bridging Therapy in Large Vessel Occlusion

Abstract

Objective:To evaluate the comparative safety and efficacy of direct endovascular thrombectomy(dEVT) compared to bridging therapy(BT:IV-tPA+EVT) and assess if BT potential benefit relates to stroke severity, size and initial presentation to EVT vs. non-EVT center.Methods:In a prospective multicenter cohort-study of imaging selection for endovascular thrombectomy[SELECT], anterior-circulation large vessel occlusion (LVO) patients presenting to EVT-capable centers within 4.5hours from last-known-well were stratified into BT vs. dEVT. The primary outcome was 90-day functional independence[modified Rankin Scale(mRS)=0-2]. Secondary outcomes included a shift across 90-day mRS grades, mortality, symptomatic intracranial hemorrhage. We also performed subgroup-analyses according to initial presentation to EVT-capable center (direct versus transfer), stroke severity and baseline infarct core volume.Results:We identified 226 LVOs (54%:men, mean age:65.6±14.6years, median NIHSS-score: 17, 28% received dEVT). Median time from arrival to groin-puncture did not differ in BT-patients when presenting directly[dEVT:1.43 (IQR=1.13-1.90) hours vs. BT:1.58(IQR=1.27-2.02)hours,p=0.40] or transferred to EVT-capable centers[dEVT:1.17 (IQR: 0.90-1.48) hours vs. BT:1.27 (IQR: 0.97-1.87) hours,p=0.24]. BT was associated with higher odds of 90-day functional independence (57% vs. 44%,aOR=2.02,95%CI:1.01-4.03,p=0.046) and functional improvement (adjusted cOR=2.06,95%CI:1.18-3.60,p=0.011), and lower likelihood of 90-day mortality (11% vs. 23%,aOR: 0.20,95%CI:0.07-0.58,p=0.003). No differences in any other outcomes were detected. In subgroup-analyses, BT patients with baseline NIHSS-scores<15 had higher functional independence likelihood compared to dEVT (aOR=4.87,95%CI:1.56-15.18,p=0.006); this association was not evident for patients with NIHSS-scores≥15 (aOR=1.05,95%CI:0.40-2.74,p=0.92). Similarly, functional outcomes improvements with BT were detected in patients with core volume strata (Ischemic core <50cc: aOR: 2.10, 95% CI:1.02-4.33, p=0.044 vs ischemic core ≥50cc: aOR: 0.41,95% CI:0.01-16.02,p=0.64) and transfer status (transferred: aOR: 2.21,95% CI:0.93-9.65,p=0.29 vs direct to EVT center: aOR:1.84,95%CI:0.80-4.23,p=0.15).Conclusions:Bridging therapy appears to be associated with better clinical outcomes, especially with milder NIHSS-scores, smaller presentation core volumes and those who were “dripped and shipped”. We did not observe any potential benefit of bridging therapy in patients with more severe strokes.Classification of Evidence:This study provides Class III evidence that for patients with ischemic stroke from anterior-circulation LVO within 4.5 hours from last-known-well, bridging therapy compared to direct endovascular thrombectomy leads to better 90-day functional outcomes.

European Stroke Organisation (ESO)–European Society for Minimally Invasive Neurological Therapy (ESMINT) expedited recommendation on indication for intravenous thrombolysis before mechanical thrombectomy in patients with acute ischemic stroke and anterior circulation large vessel occlusion

“…The investigators documented an overall shift toward better functional outcomes with bridging therapy compared with direct MT (adjusted cOR 4.51, 95% CI 1.44 to 14.15). The rates of 90-day good functional outcome were numerically but non-significantly higher in the bridging therapy group (47% vs 29%, p=0.14); similarly, the rates of 90-day mortality were numerically but non-significantly lower in the bridging therapy group (13% vs 29%, p=0.10), while the two groups had similar sICH rates 49. These findings were reproduced by a single-center German study that reported higher rates of excellent functional outcome (mRS scores 0–1 or return to prestroke mRS-score) in ‘drip and ship' patients receiving bridging therapy (23% vs 14% for direct MT) 46.…”

“…A subgroup analysis of the SELECT (Optimizing Patient Selection for Endovascular Treatment in Acute Ischemic Stroke) study evaluated LVO patients who were ‘dripped’ in primary stroke centers and ‘shipped’ to MT-capable centers. This analysis found that the rates of excellent functional outcome (mRS scores of 0–1) were significantly higher in patients receiving bridging therapy (36%) compared with direct MT (10%) 49. The investigators documented an overall shift toward better functional outcomes with bridging therapy compared with direct MT (adjusted cOR 4.51, 95% CI 1.44 to 14.15).…”

“…The probability of reduced disability was lower in the direct MT group compared with the bridging therapy group (adjusted cOR 0.22, 95% CI 0.07 to 0.69, p=0.01), but this result was based on a single study. 49 Direct MT was not significantly associated with all-cause mortality at 90 days (OR 1.42, 95% CI 0.59 to 3.44, p=0.43; I 2 =56% figure 12). In a sensitivity analysis in which propensity score matching results from the study by Di Maria et al were used instead of unadjusted results, 50 the pooled OR for mRS 0-2 was 0.75 (95% CI 0.53 to 1.07, p=0.11; I 2 =0%).…”

“…This analysis found that the rates of excellent functional outcome (mRS scores of 0-1) were significantly higher in patients receiving bridging therapy (36%) compared with direct MT (10%). 49 The investigators documented an overall shift toward better functional outcomes with bridging therapy compared with direct MT (adjusted cOR 4.51, 95% CI 1.44 to 14.15). The rates of 90-day good functional outcome were numerically but non-significantly higher in the bridging therapy group (47% vs 29%, p=0.14); similarly, the rates of 90-day mortality were numerically but non-significantly lower in the bridging therapy group (13% vs 29%, p=0.10), while the two groups had similar sICH rates.…”

Efficacy and safety of bridging thrombolysis initiated before transfer in a drip-and-ship stroke service

“…4 Consequently, exposure times to intravenous thrombolysis before starting endovascular therapy were rather short. Furthermore, in light of the neutral results of a first randomised clinical trial investigating prehospital triage for patients with suspected LVO to enable direct transfer to an 'endovascular-ready hospital' 5 and conflicting data from observational studies, [6][7][8][9] a controversial debate regarding the optimal stroke service structure continues. 10 The basic rationale of a drip-and-ship stroke service, that is, admission to the nearest primary stroke centre, is to provide intravenous thrombolysis as early as possible.…”