Introduction: Mobile stroke unit (MSU) allows for early intravenous thrombolysis (IVT) delivery in the pre-hospital setting and is ideal for investigation into early stroke therapy. We hypothesized that there are patient characteristics which influence the rapidity of IVT delivery and Door-To-Needle (DTN) time.
Methods: We reviewed 124 patients treated with IVT on MSU from 2014-2017. Patient characteristics including age, initial National Institute of Health stroke scale (NIHSS), presence of aphasia, gaze deviation, focal motor weakness, history of atrial fibrillation, prior history of stroke or transient ischemic attack (TIA) and presence of anticoagulation (AC) were analyzed with Rank-Sum test and multivariate regression.
Results: Median door-to-needle (DTN) time was 29 minutes (interquartile range (IQR) 25-38). Median age was 63.5 years old and median initial NIHSS was 9 (IQR 6-16). Focal motor weakness was associated with shorter DTN times (29 minutes with weakness compared to 31 minutes without weakness, p = 0.01). Presence of anticoagulation was associated with longer DTN time (43 minutes with AC compared to 29 minutes without AC, p=0.04). Age, presence of aphasia, gaze deviation, total initial NIH stroke scale, history of atrial fibrillation, prior stroke or TIA were not associated with DTN times. In a multivariate regression model, focal motor weakness and history of anticoagulation but not age were associated with DTN times.
Conclusion: Focal motor weakness is a notable initial patient characteristic which drives early IVT delivery and history of anticoagulation prolonged DTN in patients treated on MSU.