Beyond Time Is Brain: Workflow Innovations From Door to Recanalization in Large Vessel Occlusion Stroke

The principle of “time is brain” has evolved from a metaphor to a quantifiable mandate in acute ischemic stroke treatment, particularly for individuals with large vessel occlusion (LVO) stroke. Delays in restoring blood flow lead to substantial neuronal loss—up to 1.9 million neurons per minute—worsening functional outcomes.¹ Whereas mechanical thrombectomy (MT) and intravenous thrombolysis (IVT) have transformed stroke care, their effectiveness depends heavily on the speed of implementation.² Faster hospital arrival to arterial puncture time is directly associated with higher successful reperfusion rates. 

Despite well-established guidelines for the treatment of individuals with LVO stroke, substantial real-world variability in treatment times may limit outcomes in this population, highlighting the need for streamlined, system-wide workflow optimization. The most favorable outcomes in individuals with LVO stroke occur when systems of care are engineered for speed and coordination to achieve swift recanalization, which includes integrating prehospital triage, rapid hospital activation, and efficient endovascular workflows.

This review article outlines innovative strategies and technologies designed to accelerate stroke care from the time of prehospital suspicion of stroke to recanalization, including advancements in prehospital care (eg, mobile stroke units [MSUs]), in-hospital protocols (eg, parallel processing), and cutting-edge technologies (eg, artificial intelligence [AI]–assisted triage, robotics) to enhance workflows for LVO stroke and improve outcomes in these individuals. The neurologist is uniquely suited to serve as both a clinical expert and systems architect in this endeavor.

MSUs: Bringing Stroke Care to the Patient’s Doorstep
MSUs are specialized ambulances equipped with portable CT scanners, point-of-care laboratories, and thrombolytics. Staffed by a multidisciplinary team, including emergency medical technicians, radiology technicians, stroke-trained nurses, and neurologists (onboard or via telemedicine), MSUs enable on-scene diagnosis and immediate IVT, significantly reducing onset-to-treatment times.³ This early intervention is imperative, because IVT within 60 minutes of onset dramatically improves functional outcomes.^4,5

Evidence supporting the utility of MSUs continues to grow. The Benefits of Stroke Treatment Delivered Using a Mobile Stroke Unit (BEST-MSU) trial (NCT02190500) showed that for every 100 patients treated using an MSU compared with regular emergency medical services (EMS) treatment, 27 experienced less disability and 11 achieved greater disability-free status at 90 days.⁶ Onset-to-needle times were significantly reduced, and more patients qualified for thrombectomy. The Berlin Prehospital or Usual Delivery in Stroke Care (B-PROUD, NCT03931616) study further demonstrated that MSU dispatch was associated with a significant shift toward better 3-month functional outcomes and lower disability compared with conventional ambulance care in Germany.⁷ A meta-analysis by Turc et al⁸ demonstrated that MSU use was associated with reductions of up to 30 minutes in treatment times and improved modified Rankin Scale scores.

MSUs also optimize prehospital triage by accurately identifying LVOs on-site.⁹ This allows direct routing of patients with LVO to comprehensive stroke centers for MT, bypassing delays from interhospital transfers. By bringing advanced diagnostics and expert assessment to the patient, MSUs extend comprehensive stroke centers’ capabilities into the prehospital environment, effectively shifting the “door” from the hospital entrance to the patient’s side and minimizing secondary transfers.

MSUs involve substantial financial investment, with purchase costs of ~$1 million USD and annual operational costs up to several hundred thousand USD.¹⁰ However, cost-effectiveness studies show that MSUs are highly cost-effective when long-term care costs are included for patients with less favorable outcomes from delayed IVT.¹¹ Staffing challenges include the limited supply of vascular neurologists and the need for extensive specialized training for all personnel. Telemedicine-based physician consultation can mitigate staffing and cost constraints associated with prehospital stroke care.¹²

Most MSUs operate in urban areas, where cost-effectiveness is favorable due to higher patient volumes.¹³ The “rendezvous” concept, where an MSU meets a conventional ambulance en route, offers a promising solution. A recent study showed that an MSU–EMS rendezvous model shortened dispatch-to-needle times by nearly 1 hour compared with standard EMS transport in rural counties, demonstrating its potential to bridge disparities in timely stroke care.¹³ Neurologists advocating for the use of MSUs should be prepared to justify their expenses by integrating clinical outcomes, long-term economic benefits, and strategic deployment models (eg, rendezvous systems) to ensure equitable access. This requires collaboration with health economists, policymakers, and EMS agencies.

AI-Assisted Triage: Early LVO Detection and Team Activation
AI is reshaping stroke care workflows by addressing the most consistent delay in acute care: time to decision-making. AI-powered stroke platforms, such as Viz.ai (San Francisco, CA) and RapidAI (San Mateo, CA), have been widely adopted to expedite acute stroke care by automating the interpretation of acute stroke neuroimaging and accelerating team communication. These systems use proprietary machine learning algorithms to analyze CT head scans without contrast; CT angiography of the head and neck; and CT perfusion studies to detect intracranial hemorrhages, LVOs, and ischemic cores and penumbras.^14,15 A key advantage of these systems is automated alerting. LVO detection algorithms can identify occlusions within 7 minutes of imaging. Alerts can be provided to the on-call stroke neurologist and interventionalist via a secure smartphone application which also displays source images, thus enabling faster decision-making. 

Real-world studies have demonstrated that these AI tools can reduce treatment delays. A cluster-randomized trial across 4 US stroke centers (NCT05838456) found that implementing automated LVO detection with mobile alerts cut the median door-to-groin puncture time from ~100 minutes to 88 minutes—an 11-minute improvement.¹⁶ Another multicenter study of >14,000 stroke cases reported that the use of an AI-based stroke care coordination platform shortened the time from hospital arrival to interventionalist notification by 30 to 40 minutes.¹⁷ The National Health Service in England reported halving transfer times (door-in-door-out was reduced from 140 to 79 minutes) after deploying an AI decision support system.¹⁸ Even modest improvements in time metrics lead to substantial gains in disability-free outcomes.

AI adoption is not without challenges. Overalerting can lead to alert fatigue, desensitizing providers to urgent notifications. Moreover, a single-center study observed no significant change in door-to-treatment times with use of AI, suggesting that benefits depend on effective integration into stroke protocols.¹⁹ Still, as of 2025, >1500 US hospitals have adopted an AI-powered stroke platform, underscoring their growing relevance. For neurologists, the priority lies in ensuring that these tools are effectively embedded into decision pathways and accompanied by training to ensure rapid, appropriate responses to AI-generated alerts.

Reperfusion is the Goal: A Call for Stroke Care System Redesign
Reducing the time to brain reperfusion, especially in people with LVO stroke, is now a recognized system-wide treatment priority. Although breakthroughs in IVT and MT have revolutionized stroke care, their real-world efficacy hinges on rapid, system-level execution. Reducing time to recanalization is no longer solely a medical act but rather a complex, cross-disciplinary engineering challenge that demands leadership from neurologists. A high-functioning stroke care system must operate as an integrated network in which prehospital teams, hospital departments (eg, vascular neurology, emergency, radiology, interventional departments), and hospital administrators coordinate their efforts with the singular purpose of achieving ultrarapid reperfusion in people with LVO stroke.²⁰

Neurologists are uniquely positioned to lead this transformation. Their involvement across the care continuum often provides a comprehensive view of workflow inefficiencies and opportunities for optimization. This leadership includes engaging EMS in developing prehospital routing protocols for LVO, implementing parallel processing in the emergency department (ED), and coordinating with radiologists and interventionalists to ensure imaging and angiography suite readiness.²¹ Using the examples of trauma and cardiac systems of care, stroke triage can ensure getting the right patient to the right place, the first time. 

A study by Man et al²² analyzing the Get With The Guidelines–Stroke Registry Tool demonstrated that implementation of the national Target: Stroke initiative (a program led by the American Heart Association/American Stroke Association providing 10 best-practice strategies to accelerate IVT therapy) reduced median door-to-needle times from 80 to 68 minutes and increased the proportion of patients treated within 60 minutes from 24.8% to 40.6%, underscoring that treatment efficiency at larger centers can offset additional transport time. Prehospital triage need not be restricted to detecting LVO; rather, distinguishing severe from milder strokes, whether ischemic or hemorrhagic, supports direct routing to higher-capability centers where timely reperfusion or specialized care is most likely to occur.

Systematic redesign of stroke systems has been shown to produce measurable improvements. A multicenter analysis by Aghaebrahim et al²³ demonstrated that lean workflow optimizations reduced door-to-recanalization times and were associated with greater functional independence at 90 days. Beyond protocol implementation, stroke systems must commit to continuous performance tracking, monitoring metrics such as door-to-imaging time and door-to-recanalization time as key performance indicators across institutions.²⁴

Ultimately, achieving faster reperfusion is not about isolated improvements, but about aligning every link in the stroke care chain toward the singular goal of preserving brain function (Table).

Hitting the Door Running: In-Hospital Workflow Innovations
To maintain the prehospital momentum, modern stroke centers rely on highly coordinated, parallel in-hospital processes that replace outdated sequential workflows. Rather than waiting for ED triage and evaluation, the stroke care team is activated prearrival, enabling simultaneous execution of tasks such as IV placement, laboratory draws, National Institutes of Health Stroke Scale scoring, and imaging preparation. Leading institutions have demonstrated that many of these actions can be completed before the patient even leaves the scanner, effectively reducing the timeline from door to decision-making.²¹

A major innovation in the optimization of stroke care is the adoption of direct-to-imaging or direct-to-angiography protocols, in which patients with suspected LVO bypass the ED entirely. Instead, they are transferred directly from the ambulance to the CT or angiography suite, a strategy shown to reduce door-to-groin puncture times by 15 to 30 minutes in real-world studies.²⁵ This protocol requires strong prehospital triage, seamless EMS communication, and high-fidelity coordination between all stroke care stakeholders. Equally transformative is the one-call activation model, which replaces traditional stepwise paging systems with a single communication that alerts all critical personnel at once—stroke neurologist, interventionalist, CT technician, and anesthesiologist—ensuring that the team assembles in parallel rather than in sequence.²⁶ These workflow upgrades are not just theoretical; institutions implementing them have shown significantly improved treatment times and outcomes, especially when paired with systematic training, simulation drills, and real-time time-tracking audits to identify bottlenecks. Ultimately, what separates high-performing stroke care systems is not merely access to thrombectomy, but the speed and cohesion with which it is delivered.

Future Directions: The Next Frontier in Speed and Access
As stroke care systems evolve, the next frontier lies in expanding both speed and equitable access to advanced stroke care. Portable CT and CT angiography units can bring diagnostic imaging directly into the field, allowing for earlier identification of LVOs and prehospital treatment stratification. Coupled with AI-guided triage platforms, these tools could dramatically accelerate patient selection for IVT or MT even before hospital arrival. Other transformative concepts include the robotic-assisted thrombectomy system and tele-directed endovascular procedures.²⁷ Currently in early clinical development, these systems may one day enable expert intervention across geographic boundaries, guided remotely from comprehensive stroke centers. In addition, the integration of personalized routing algorithms using physiologic and imaging biomarkers may allow dynamic, real-time transport decisions that optimize both access and outcome. The convergence of these technologies is pushing stroke care toward a hybrid future where location is no longer a limiting factor, and where the “door” can be redefined by data rather than distance. 

Conclusion: Leading the Charge Toward Faster Stroke Systems
Successful reperfusion is the product of a system, not a single intervention. “Time is brain” has become a performance benchmark, measurable across stroke registries, quality metrics, and patient outcomes. As the specialists best equipped to understand stroke pathophysiology and systems design, neurologists must champion this evolution. From pushing MSU deployment to guiding AI adoption to refining in-hospital flow to supporting future-facing technologies, neurologists are the drivers of progress and future success. The path to improving stroke outcomes does not hinge solely on new therapies, but also on optimizing how, when, and where existing therapies are delivered.