Abstract WP81: Patient Characteristics Between Last Known Well and Symptom Onset Time: Patterns in the Time is Brain Study

Abstract

Background: Acute reperfusion treatment reduces morbidity in Acute Ischemic Stroke (AIS). National guidelines use Last Known Well (LKW) estimates to determine eligibility. When LKW and symptom onset (SO) are “coupled,” treatment eligibility determination is easier. However, eligibility becomes complex when times are “decoupled,” such as in wake-up strokes. We aimed to understand social differences in AIS patients with coupled vs decoupled LKW and SO times. Methods: Time is Brain is an ongoing, multicenter study assessing effects of social network dynamics on pre-hospital delay in socioeconomically disadvantaged stroke patients. Demographics, stroke characteristics, tPA administration, LKW, and SO times were collected from electronic medical records or interviews from Jan to Jul 2023. Symptom onset-to-door (OTD) times were calculated. Fourteen out of seventy patients diagnosed with intracerebral hemorrhage or transient ischemic attack were excluded. Fifty-six were divided into Coupled or Decoupled LKW/SO conditions. Mann-Whitney U , and Fisher’s exact or Pearson X 2 tests were performed. Significance was defined as p<0.05. Results: Fifty-six patients diagnosed with AIS have been enrolled (mean age 67.0± 14.3, 54.3% Female, median NIHSS 2). 87.5% (n=49) self-identified as non-Hispanic and 17.9% (n=10) as Black. Fourteen patients had coupled and forty-two had decoupled LKW/SO times. Among those with decoupled times, 81.0% (n=34) had onset at home and 26.2% (n=11) awoke with symptoms. Cortical AIS was prevalent in both groups (58.8% v. 41.5%, p-value: 0.815). EMS use (58.8% v. 60.4%, p-value: 0.762) and tPA administration (23.5% v. 18.9%, p-value: 1.000) were comparable. Decoupled LKW/SO patients less commonly presented with dysarthria than coupled patients (29.4% v. 54.7%, p=0.036). Median OTD time of coupled v. decoupled groups was 458.5 v.105 min (IQR: 101.25-996.75 v. 60-390.0; p-value: 0.048). Conclusions: In our preliminary analysis of this multicenter cohort, three out of every four AIS stroke patients presented with decoupled LKW/SO times. Decoupling commonly occurred outside the wake-up stroke setting. Ongoing studies will discern patient-level social and clinical characteristics that describe these two important AIS populations.