Intro: Shorter door-to-needle time (DTN) is associated with better outcomes for ischemic stroke. National increases in tPA volumes are partially driven by treatment of larger numbers of minor strokes. However, it is not known whether treatment times differ in these patients. We sought to evaluate DTN and component times in minor strokes.
Hypothesis: In minor strokes DTN is longer due to more diagnostic uncertainty
Methods: We reviewed the record of all patients who received tPA in our ED from 7/2011-7/2015. Minor stroke was defined as NIHSS≤5. We compared demographics, EMS usage, pre-notification rates and DTN between minor strokes and all others. We also compared DTN component times, specifically neurologist-dependent times where diagnostic uncertainty may be apparent (stroke activation (SA)-to-tPA and imaging-to-tPA) and ED-dependent times which capture initial stroke recognition (door-to-SA and door-to-imaging). Means were compared via t test, medians via Mann Whitney U test, and dichotomous variables via chi square test.
Results: Over this period 311 patients received tPA; 126 (41%) were minor strokes. There were no significant differences in language (48 vs 52% English-speaking, p=0.6) or sex (39 vs 34% male, p=0.3) for minor strokes compared to all others. Minor strokes were younger (62 vs 73 years, p<0.01), less likely to use EMS (55 vs 80%, p<0.01), and less likely to receive pre-notification by EMS (43 vs 71%, p<0.01).
We found longer DTN (61 vs 55 min, p=0.01) in minor strokes compared to all others. For DTN components, door-to-SA (5 vs 2 min, p<0.01) and door-to-imaging (27 vs 21 min, p<0.01) were longer in minor strokes while imaging-to-tPA (33 vs 32 min, p=1.0) and SA-to-tPA (50 vs 51 min, p=0.5) were not. In the subgroup arriving by EMS, these differences persisted although they were no longer significant (DTN 59 vs 54 min, p=0.4; door-to-SA 4 vs 1 min, p=0.05; door-to-imaging 25 vs 20 min, p=0.05).
Conclusion: We found longer DTN in minor strokes. The difference in door-to-stroke activation and door-to-imaging but not other component times suggests delayed recognition of minor strokes at ED presentation. Similarly, less frequent pre-notification points to poor recognition by EMS. Efforts are needed to improve minor stroke recognition by EMS and ED providers