BACKGROUND: Recent years have seen improvements in stroke-care pathways, including mobile stroke units (MSUs), and this may have affected the rate, predictors, and outcomes of patients with acute ischemic stroke who qualify for but do not receive treatment with intravenous thrombolysis (IVT). METHODS: This was a secondary observational cohort analysis of the prospective, multicenter BEST-MSU trial (Benefits of Stroke Treatment Delivered by a Mobile Stroke Unit Compared With Standard Management by Emergency Medical Services), conducted in 7 US cities from 2014 to 2020, comparing MSU management versus standard emergency department management for patients with suspected acute ischemic stroke. The analytical cohort comprised enrolled patients with confirmed acute ischemic stroke and no guideline contraindications to IVT. The outcome was a potential missed IVT opportunity, defined as patients not treated with IVT despite lacking contraindications. We used multivariable logistic regression to evaluate whether demographics, prestroke modified Rankin Scale, study site, comorbidities, National Institutes of Health Stroke Scale, blood pressure, international normalized ratio, glucose, antithrombotic use, and thrombectomy were associated with this outcome. RESULTS: Of 1515 enrolled patients, 927 met criteria for this analysis. Fifty-one participants (5.5%) had a potential missed IVT opportunity, including 4 of 555 (0.7%) in the MSU group versus 47 of 372 (12.6%) in the emergency department group (odds ratio, 0.05 95% CI, 0.02–0.12). In multivariable analysis, omitting study group, lower National Institutes of Health Stroke Scale (odds ratio, 0.95 95% CI, 0.90–0.99) and longer last known well-to-door time (odds ratio per 10 minutes, 1.08 95% CI, 1.03–1.13) were independently associated with a potential missed IVT opportunity. The leading reasons documented for withholding IVT were resolving symptoms (43%), time window concerns (18%), and minor deficits (10%). Among participants with a potential missed IVT opportunity and a recorded 3-month modified Rankin Scale (n=49), 19 (39%) had a score of 3 to 6. CONCLUSIONS: In the BEST-MSU trial, potential missed IVT opportunities occurred in 1-in-8 patients in the emergency department, and rarely on the MSU. Although often due to early improvement or minor deficits, more than one-third of these patients had poor functional status at 3 months. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02190500.
Navi et al. (Thu,) studied this question.