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Updated October 2025
Stroke Emergency Care

Acute Ischemic Stroke: Triage, Thrombolysis, and Thrombectomy

For suspected acute ischemic stroke, rapid triage prioritizes last-known-well ascertainment, large-vessel-occlusion (LVO) screening, and parallel imaging. Intravenous thrombolysis within 4.5 hours improves outcomes and should be provided when eligible without delaying endovascular thrombectomy. Mechanical thrombectomy is standard of care for anterior-circulation LVO within 6 hours and, with imaging selection, up to 24 hours. Perfusion- or DWI/CTP-based selection expands the late window and optimizes benefit–risk.

Clinical question
How should clinicians triage and treat adults with suspected acute ischemic stroke, including the roles of thrombolysis and mechanical thrombectomy across early and late time windows?
StrokeThrombolysisThrombectomyPerfusion ImagingEmergency MedicineNeurology
Key points
Front-door triage
Activate code stroke at triage, document last-known-well, perform FAST-ED/NIHSS-LVO screen, and obtain parallel labs and non-contrast CT with CTA ± CTP to identify hemorrhage and LVO rapidly [4], [3].
Early IV thrombolysis
Administer IV alteplase/tenecteplase within 4.5 hours when eligible; do not delay or withhold for potential EVT transfer—bridging is generally safe and standard in many systems [7], [11], [13].
Mechanical thrombectomy
Perform EVT for anterior-circulation LVO up to 6 hours; with DAWN/DEFUSE 3–style selection and perfusion imaging, benefit extends to 16–24 hours after last-known-well [1], [3], [9].
Bridging vs direct EVT
Randomized data (e.g., DIRECT-MT, SKIP) and meta-analyses show non-inferiority signals for EVT alone in select populations, but system-level practice often favors bridging when not contraindicated; shared protocols recommended [10], [14], [15].
Systems of care
Prehospital LVO routing and in-hospital code-stroke pathways shorten door-to-needle and door-to-groin times and improve outcomes; ensure 24/7 EVT capability or rapid transfer [4], [5], [9].
Evidence highlights
Substantial disability reduction in anterior LVO ≤6 h; benefit consistent across trials [1]
Early EVT efficacy
DAWN/DEFUSE 3 criteria extend EVT to 16–24 h with imaging selection; robust mRS benefit [1]
Late window EVT
IVT+EVT vs EVT alone: mixed RCT/meta-analytic signals; functional outcomes similar in several trials; reperfusion nuances persist [10], [14], [15]
Bridging strategy
ED Pathway
Time-Critical Triage and Imaging
Prioritize rapid identification of LVO and eligibility for reperfusion therapies while minimizing door-to-needle and door-to-groin times.
1
Immediate triage and activation
Activate code stroke at triage. Record exact last-known-well. Perform glucose check and LVO screen (e.g., FAST-ED, RACE). Parallel labs and IV access. Notify CT/IR teams early to compress timelines [4], [5].
2
Imaging sequence
Obtain non-contrast CT to exclude hemorrhage, then CTA head/neck to detect LVO. Add CTP or DWI/PWI MRI when late-window or clinical–imaging mismatch is suspected to estimate core vs penumbra for triage to EVT [1], [3].
3
Early-window thrombolysis (≤4.5 h)
If no contraindication, deliver IV thrombolytic promptly. Begin transfer to EVT center in parallel if LVO suspected/confirmed; do not delay IVT for EVT logistics [7], [11], [13].
4
Endovascular thrombectomy (EVT)
Offer EVT for ICA/M1 (and selected M2/posterior) occlusions ≤6 h. In 6–24 h window, select patients using DAWN/DEFUSE 3–like criteria with perfusion or DWI–FLAIR mismatch to identify salvageable tissue [1], [3], [9].
5
Bridging vs direct EVT
Where timely IVT is feasible and not contraindicated, many systems favor bridging. RCTs (e.g., DIRECT-MT, SKIP) show similar 90-day mRS with direct EVT in some settings; develop local protocols reflecting capabilities and transfer times [10], [14], [15].
Therapy
Thrombolysis and Thrombectomy: Key Points
Evidence-based criteria that drive decision-making across windows.
Time windows
IV thrombolysis: strongest evidence ≤4.5 h from last-known-well [7], [11], [13]
EVT: standard ≤6 h for anterior-circulation LVO [1]
Late-window EVT: 6–16 h (DEFUSE 3) and 6–24 h (DAWN) with imaging selection [1], [3]
Imaging selection
NCCT to exclude hemorrhage; CTA to confirm LVO [4], [9]
Perfusion CT/MR to define core/penumbra and clinical–imaging mismatch in late window [1], [3]
Use standardized thresholds and automated software when available to reduce delays [3]
IVT pearls
Administer promptly when eligible; benefits include improved reperfusion and functional outcomes in early window [11], [13]
Do not delay for EVT workup—start IVT while arranging endovascular care (bridging) [7], [11]
Tenecteplase is an accepted alternative in many systems; follow local protocols [7]
EVT indications
Anterior-circulation LVO (ICA terminus/M1) with disabling deficits; consider M2/posterior on case-by-case basis [1], [9]
Late window requires small core and substantial penumbra or clinical–core mismatch (e.g., DAWN/DEFUSE 3) [1], [3]
Aim for fast puncture-to-reperfusion times; first-pass effect improves outcomes
Bridging vs direct EVT
DIRECT-MT and SKIP suggest non-inferiority of direct EVT on 90-day mRS in specific Asian cohorts; global generalizability is debated [10]
Meta-analyses show similar functional outcomes but nuanced differences in early reperfusion and symptomatic ICH; protocolize per system [14], [15]
If IVT eligible and no significant delay, many centers still favor bridging to maximize early recanalization [11], [14]
Systems and equity
Prehospital LVO routing and ED ‘code-LVO’ pathways shorten time-to-treatment and improve outcomes [4], [5]
Access gaps persist; organized transfer networks are critical to deliver EVT benefits broadly [5], [8], [9]
References
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