Abstract 179: Functional Outcomes of Pre-hospital Stroke Thrombolysis Compared to Conventional Care; the Stroke Emergency Mobile (STEMO) Project

Effect of prehospital workflow optimization on treatment delays and clinical outcomes in acute ischemic stroke: A systematic review and meta-analysis

BACKGROUND

The prehospital phase is critical in ensuring that stroke treatment is delivered quickly and is a major source of time delay. This study sought to identify and examine prehospital stroke workflow optimizations (PSWOs) and their impact on improving health systems, reperfusion rates, treatment delays, and clinical outcomes.

METHODS

The authors conducted a systematic literature review and meta-analysis by extracting data from several research databases (PubMed, Cochrane, Medline, and Embase) published since 2005. We used appropriate key search terms to identify clinical studies concerning prehospital workflow optimization, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

The authors identified 27 articles that looked at the impact of prehospital workflow optimizations on time and treatment parameters; 26 were included in the meta-analysis. The PSWO were subgrouped into three categories: improved intravenous thrombolysis (IVT) triage, large-vessel occlusion (LVO) bypass, and mobile stroke unit (MSU). The salient findings are as follows: improved IVT triage led to significantly improved rates of IVT (relative risk [RR] = 1.80, 95% confidence interval [CI] = 1.18 to 2.75); however, MSU did not (RR = 1.22, 95% CI = 0.98 to 1.52). Improved IVT triage (standard mean difference [SMD] = -0.82, 95% CI = -1.32 to -0.32), LVO bypass (SMD = -0.80, 95% CI = -1.13 to -0.47), and MSU (SMD = -0.87, 95% CI = -1.57 to -0.17) were found to significantly reduce door-to-needle time for IVT. MSU was found to significantly reduce call-to-needle (SMD = -1.41, 95% CI = -1.94 to -0.88) and onset-to-needle (SMD = -1.15, 95% CI = -1.74 to -0.56) times for IVT. MSU additionally demonstrated significant reduction in door-to-perfusion (SMD = -0.72, 95% CI = -1.32 to -0.12) as well as call-to-perfusion (SMD = -0.73, 95% CI = -1.08 to -0.38) times for EVT. Finally, PSWO did not demonstrate significant improvements in rates of good functional outcome (RR = 1.04, 95% CI = 0.97 to 1.12) or mortality at 90 days (RR = 1.00, 95% CI = 0.76 to 1.31).

CONCLUSIONS

This systematic review and meta-analysis found that PSWO significantly improves several time metrics related to stroke treatment leading to improvement in IVT reperfusion rates. Thus, the implementation of these measures in stroke networks is a promising avenue to improve an often-neglected aspect of the stroke response. However, the limited available data suggest functional outcomes and mortality are not significantly improved by PSWO; hence, further studies and improvement strategies vis-à-vis PSWOs are warranted.

Melbourne Mobile Stroke Unit and Reperfusion Therapy

Background and Purpose—

Mobile stroke units (MSUs) are increasingly used worldwide to provide prehospital triage and treatment. The benefits of MSUs in giving earlier thrombolysis have been well established, but the impacts of MSUs on endovascular thrombectomy (EVT) and effect on disability avoidance are largely unknown. We aimed to determine the clinical impact and disability reduction for reperfusion therapies in the first operational year of the Melbourne MSU.

Methods—

Treatment time metrics for MSU patients receiving reperfusion therapy were compared with control patients presenting to metropolitan Melbourne stroke units via standard ambulance within MSU operating hours. The primary outcome was median time difference in first ambulance dispatch to treatment modeled using quantile regression analysis. Time savings were subsequently converted to disability-adjusted life years avoided using published estimates.

Results—

In the first 365-day operation of the Melbourne MSU, prehospital thrombolysis was administered to 100 patients (mean age, 73.8 years; 62% men). The median time savings per MSU patient, compared with the control cohort, was 26 minutes ( P <0.001) for dispatch to hospital arrival and 15 minutes ( P <0.001) for hospital arrival to thrombolysis. The calculated overall time saving from dispatch to thrombolysis was 42.5 minutes (95% CI, 36.0–49.0). In the same period, 41 MSU patients received EVT (mean age, 76 years; 61% men) with median dispatch-to-treatment time saving of 51 minutes ([95% CI, 30.1–71.9], P <0.001). This included a median time saving of 17 minutes ([95% CI, 7.6–26.4], P =0.001) for EVT hospital arrival to arterial puncture for MSU patients. Estimated median disability-adjusted life years saved through earlier provision of reperfusion therapies were 20.9 for thrombolysis and 24.6 for EVT.

Conclusions—

The Melbourne MSU substantially reduced time to reperfusion therapies, with the greatest estimated disability avoidance driven by the more powerful impact of earlier EVT. These findings highlight the benefits of prehospital notification and direct triage to EVT centers with facilitated workflow on arrival by the MSU.