Direct Transfer to Angiography Following Mobile Stroke Unit Leads to Less Successful Recanalization, Increased Mortality

Findings from a retrospective chart review comparing patients with emergent large vessel occlusion (ELVO) showed that a direct-to-angiography approach from mobile stroke unit (MSU) was associated with less successful recanalization and increased mortality than opting for additional imaging studies first.

These data were presented at the 2023 International Stroke Conference (ISC), held February 8-10, in Dallas, Texas, by senior investigator Shazam Hussain, MD, FRCP, FAHA, director of the Cerebrovascular Center at Cleveland Clinic. The study featured 14 patients with ELVO who went directly to angio (DTA) and 52 patients who underwent additional imaging (CTA), with no differences in age, gender, pre-morbid vascular risk factors or presenting symptoms.

"The important thing to note about CT angiography on mobile stroke units is at that the current scanners only do head up imaging," Hussain told NeurologyLive®. "We don’t get a visualization of the neck, which can be very important from planning purposes. We suspect that this might be part of the reason why we’re seeing this difference in groups. Perhaps, while getting the CTA on the vehicle seems like an appealing idea, maybe it’s more about identifying those patients, getting the thrombolysis in the field, getting them to a center, and then getting the additional necessary workup that you need to optimize the situation."

Not only did the DTA group have a higher, but non-significant, initial median National Institutes of Health Stroke Scale (NIHSS) score, this group received more thrombolytic therapy relative to those who underwent additional imaging (P = .003). Additionally, with a median of 39 minutes, the DRA group had better door-to-groin times than those in the CTA group, who reported median times of 51.5 minutes (P = .02). Grades between 0-2a on the thrombolysis in cerebral infarction (TICI) system, used to determine the response of thrombolytic therapy for ischemic stroke, wore more frequently seen in the DTA group (35.7%) compared with the CTA group (9.6%; P = .03).

"These mobile stroke units have shown to decrease time to treatment, improve outcomes, and now we’re seeing the cost effectiveness analyses come out as well," Hussain added. "The place of mobile stroke is there, and we’re really getting into the nuances as we are in many areas within stroke. How can we optimize things for individual patients? It’s an exciting time, and we’re seeing a lot of interesting studies trying to understand these workflows. What are the little adjustments and tweaks that we need to make to optimize these workflows and get patients the best change at a good outcome."

READ MORE: 3-Year Follow-Up of STROKE-AF Demonstrates Stroke Risk Increase With Atrial Fibrillation

At the conclusion of the analysis, the mortality rate was significantly higher in the DTA group (35% vs 9%; P = .028); however, there was no between-group difference in functional outcomes, as assessed using modified Rankin Scale scores between 0-2 (28% vs 17%; P = .45). Additionally, between groups, there was a non-significantly higher incidence of tandem occlusions in the DTA group (28.5% vs 15%; P = .43), which may have played a factor into the results, Hussain noted.

"Worldwide, we’re seeing more places adopting the idea of inputting mobile stroke units," Hussain concluded. "We have excellent studies out of Berlin and Houston that have proven the outcome benefit. From a guidelines perspective, we’ll see if the new guidelines become more adopted. We know that ESO guidelines have promoted a high rating for mobile stroke units, which is important."

MSUs are becoming more prevalent across the world; however, there are still only a few major programs. One study, the phase 3 BEST-MSU trial (NCT02190500), has highlighted the impact MSUs have on disability and other stroke outcomes relative to standard management. In a cohort of 598 patients treated by MSUs, findings presented at ISC 2021 showed mean weighted mRS scores of 0.726 compared with scores of 0.657 in those treated with standard management (P = .002). Based on these findings, for every 100 patients treated with an MSU rather than standard management, 27 more will have less final disability and 11 more will be disability free, indicated by mRS scores of 0 or 1.

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REFERENCES
1. Martucci M, Toth G, Buletko A, Khawaja Z, Russman AN, Hussain MS. Mobile stroke unit: direct to angio or some stops along the way? Presented at: 2023 International Stroke Conference; February 8-10; Dallas, TX. Abstract WMP85
2. Grotta JC, Parker S, Gonzalez NR, et al. Benefits of stroke treatment delivered by a mobile stroke unit compared to standard management by emergency medical services (BEST-MSU study). Presented at International Stroke Conference 2021; March 17–19. Abstract LB 2