Hello, my name is Brittany Owusu-Ajay Thompson. I'm an incoming neurosurgery resident at the University of Massachusetts, and this is my senior author, Dr. Ralph Ramey, a neurosurgeon at St. Barnabas Hospital in the Bronx. We have no disclosures. This map is one that you are all probably familiar with, showing the rate of stroke hospitalizations throughout the United States. As you can see, the highest rates are within the eastern southern United States, known as the stroke belt. New York is not part of the stroke belts, but if we zoom in, we can see that the Bronx is New York's own stroke belt, with a population of 1.4 million and six designated stroke centers, five primary stroke centers, and one comprehensive stroke center. This is a map of the Bronx and all its local hospitals. Circled in red is St. Barnabas Hospital, one of the five primary stroke centers in the Bronx. In 2019, New York State implemented a set of pre-hospital guidelines for EMS to use when assessing a potential stroke patient. Upon arrival, EMS evaluates the patient for any new neurological deficits. If deficits are present, they then use the SLAM scoring system to assess facial droop, arm drift, speech deficit, and grip strength. A score ranging from zero to six is given, with a lower score of zero to three being better than four or greater. Patients with a score of zero to three are transported to a primary stroke center. Patients with a score of four or greater have to be assessed further for the presence of trauma or seizure as a cause, wheelchair bound or bed bound at baseline, loss of consciousness, less known while greater than five hours, and transport time to a thrombectomy stroke center greater than 30 minutes. These specific criteria were designed to prevent the transport of patients to thrombectomy centers that would not be candidates for thrombectomy treatment. If none of these criteria are met, then the patient is transported to a thrombectomy-capable stroke center. Previous studies have assessed the accuracy of stroke prediction instruments for diagnosing large vessel occlusion strokes. This systematic review done by the American Heart Association and the American Stroke Association analyzed various prediction instruments, including LAMs, indicating low rates of sensitivity, variable specificity, with a very low positive predictive value of only 50 to 60%, and a negative predictive value of less than 90%. However, currently there is no real world data on these scoring systems and their accuracy on predicting large vessel occlusion strokes. For this purpose, we performed a retrospective chart review from a prospective database of all patients brought in by EMS with a presumptive diagnosis of stroke to St. Barnabas Hospital in the fiscal year of 2018. We retrospectively applied this cohort to the 2019 guidelines that were not available at that time, calculating the LAMs and SLAMs for these patients using the available clinical data. Our cohort consisted of 181 patients, 98 female, 83 male, with a mean age of 68 years old and racial demographics similar to the population in the Bronx. Negative stroke cases were ischemic or transient ischemic attack with a mean NIH stroke scale of 6.8, mean LAMs and SLAMs of 1.8 and 2.3, respectively. Of this cohort, 14 patients received IV thrombolysis and 16 cases of LVO were confirmed and transferred to a thrombectomy-capable stroke center. When the 2019 guidelines were applied to the 2018 cohort, we found 49 patients had an SLAMs of 4 or greater. Of these 49, 17 would have met exclusion criteria, 32 of the patients would have been taken directly to a thrombectomy stroke center, while up to a third of LVOs would have been missed by this protocol and brought to St. Barnabas Hospital. For more details on these results, please reference our poster number 1127. There was a clear difference between the LAMs, SLAMs, and NIH stroke scale scores in LVO stroke patients in comparison to non-LVO stroke patients, with higher scores in patients with LVO stroke. All p-values were found to be statistically significant across the scoring systems. We found the same data when we broke down the scores based on thresholds, with a threshold of 4 for LAMs and SLAMs and 12 for NIH stroke scale. LVO stroke patients received higher scores of 4 or greater on the LAMs and SLAMs and 12 or greater on NIH stroke scale. The New York 2019 criteria for transportation showed statistically more patients with LVO than non-LVO. Despite the positive association between higher scores and the presence of LVO stroke, we found sensitivities to be low throughout, ranging from 53.3 to 78.6%, and extremely low positive predictive values ranging from as low as 20.4 to as high as 31.4%. This explains why up to a third of LVO strokes are missed on the field and also explains the high rate of false positives. In conclusion, sensitivity and positive predictive value of LAMs, SLAMs, and New York 2019 guidelines for LVO stroke are poor. Non-LVO strokes are flagged more than twice as often than LVO strokes. Up to a third of LVOs are missed. A more reliable prediction instrument is needed to better guide EMS on where to transport patients for proper stroke care. Thank you.

stroke hospitalizations

Bronx, New York

pre-hospital guidelines

SLAM scoring system

large vessel occlusion strokes