Abstract TP219: Positive Predicative Value of a Screening Tool in the Detection of Large Vessel Occlusion Stroke

Introduction: Randomized controlled trials have shown that endovascular thrombectomy (EVT) improves functional outcomes in patients with acute ischemic stroke secondary to a large vessel occlusion (LVO). The odds of a favorable clinical outcome with EVT are increased when onset to puncture times are reduced. Although the BEFAST screen, which is commonly used in most emergency rooms to detect stroke, is a sensitive tool, it does not differentiate between stroke subtypes. A targeted LVO screening tool that is fast, easy to use, and reliable can help detect LVO sooner, hastening delivery of emergency treatment to improve the odds of a favorable functional outcome. Objective: This project seeks to determine the positive predictive value (PPV) of a criteria-based early LVO screening tool for the detection of large vessel occlusion. Methods: One hundred and four patients across two hospitals with a positive BEFAST stroke assessment were evaluated with the “Early LVO Screen” from February 2024 to July 2025. Three criteria were included in the screening tool: gaze deviation, aphasia, and NIHSS ≥ 10. A positive screen indicated the patient had one or more of these criteria on initial clinical presentation. Patient positive screens were then compared with findings on standard vascular imaging. Results: A positive screen was noted in 104 patients. Forty-six of the 104 patients were found to have confirmed LVO on imaging, indicating a 44% overall PPV of the screen. Aphasia and NIHSS score ≥10 were the most common criteria detected in 67% of screened patients and together had a 66% PPV for detecting LVO. Gaze deviation was seen in 52% of patients and had a 61% PPV for detecting LVO. When gaze was combined with NIHSS > 10, the PPV for detecting LVO was 67%. When all three criteria were present, the PPV for identifying patients with LVO was 73%. Conclusion: The “Early LVO screen”, especially when all three criteria are present, is a quick and reliable screening tool that has a high PPV for detecting LVO prior to confirmation with vessel imaging. Having only three criteria to assess makes this an easy-to-use tool that can be utilized by neurology and non-neurology providers alike, with applications spanning pre-hospital and emergency room settings. By identifying patients with LVO sooner, this tool may be useful in decreasing time to neuroendovascular team notification and mobilization, in turn, hastening the delivery of life saving treatment to acute stroke patients.