Abstract TMP8: Predictors of Large Vessel Occlusion in Kaiser Stroke EXPRESS Program

Abstract

Background: In 2015, trials showed that rapid endovascular stroke treatment (EST) of qualified patients with large vessel occlusion (LVO) resulted in improved outcomes over treatment with IV tPA alone. In 2015, Kaiser Permanente Northern California (KPNC) redesigned its acute stroke care work flow for its 21 stroke centers, which included expedited IV t-pa treatment, rapid CTA investigation, expedited transfer of appropriate patients for EST. We assessed for predictors of LVO post-implementation. Methods: The KPNC Stroke EXPRESS program was live in all centers by January 2016. Using clinical data for 1/1/16 - 7/10/16, we evaluated the frequency and locations of LVO, and patient characteristics of those with LVO. Multivariate logistic regression was used to examine whether age, gender, race, or an NIHSS ≥ 8 are predictors of LVO. Results: There were 2,204 tele-stroke alert cases from the ED. Among 993 (39.3%) that proceeded as likely acute stroke, 812 (81.8%) were evaluated with CTA. Out of those who had a CTA, 152 (18.7%) were found to have LVO as followed: 27 (17.8%) ICA, 87 (57.2%) M1, 24 (15.8%) M2, 6 (4.0%) basilar, 5 (3.3%) PCA, and 3 (2.0%) vertebral. Of those with LVO, 97 (63.8%) were treated with EST. Patients with LVO had a higher median NIHSS (15 vs. 5 in those without LVO). Neglect (27% vs. 7%) and gaze deviation (16% vs. 1%) were more likely to be seen among those with LVO and treated with EST compared to those without LVO. In multivariate analysis, age (OR=1.02, 95% CI 1.00 - 1.03, p=0.01) and NIHSS ≥8 (OR = 4.99, 95% CI 3.32- 7.49, p < 0.001) were associated with LVO. PPV for NIHSS ≥8 was 75.7%. Conclusions: In our large multi-ethnic population of acute stroke patients, a relatively small percentage (19%) was found to have LVO and only a subset qualified for EST. Predictors of LVO included NIHSS ≥8, increasing age, and presence of neglect and gaze preference. Given the low numbers of patients brought in for acute stroke treatment who ended up with a LVO requiring EST, further research is needed to assess a given system’s ability to rapidly evaluate and transfer as appropriate for EST rather than paramedic based diversion.