February 12, 2020
Study Evaluates Population Access to Endovascular Thrombectomy for Acute Ischemic Stroke
February 12, 2020—Amrou Sarraj, MD, et al conducted a study of current access paradigms and optimization methodology of endovascular thrombectomy (EVT) for acute ischemic strokes in the United States. The findings are available online ahead of print in Stroke.
The investigators found that EVT-access within 15 minutes is limited to less than one-fifth of the United States population. Additionally, optimization methodologies that increase EVT centers or bypass non-EVT to the closest EVT center both showed enhanced access. Results varied by states based on the population size and density. However, bypass showed more potential for maximizing direct EVT-access.
National and state efforts should focus on identifying gaps and tailoring solutions to improve EVT-access, concluded the investigators in Stroke.
For the study, the investigators mapped United States stroke-treating centers using geomapping and stratified into non-EVT or EVT if they reported one or more acute ischemic stroke thrombectomy codes in 2017 to the Centers for Medicare & Medicaid Services.
Direct EVT-access, defined as the population with the closest facility being an EVT-center, was calculated from validated trauma models adapted for stroke.
Current 15- and 30-minute access were described nationwide and at state-level with emphasis on four states (Texas, New York, California, Illinois).
The study used two optimization models, A and B. Model-A used a greedy algorithm to capture the largest population with direct access when flipping 10% and 20% non-EVT to EVT-centers to maximize access. Model-B used bypassing methodology to directly transport patients to the nearest EVT centers if the drive-time difference from the geocentroid to the hospital was within 15 minutes from the geocentroid to the closest non-EVT center.
As summarized in Stroke, 713 (37%) of 1,941 stroke centers were EVT. Approximately 61 million (19.8%) Americans have direct EVT access within 15 minutes and 95 million (30.9%) have access within 30 minutes.
In Texas, there were 65 (43%) EVT centers with 22% of the population currently within 15-minute access. Flipping 10% of hospitals with top population density improved access to 30.8% while bypassing resulted in 45.5% having direct access to EVT centers.
Similar results were found in New York (current, 20.9%; flipping, 34.7%; bypassing, 50.4%), California (current, 25.5%; flipping, 37.3%; bypassing, 53.9%), and Illinois (current, 15.3%; flipping, 21.9%; bypassing, 34.6%).
Nationwide, the current direct access within 15 minutes of 19.8% increased by 7.5% by flipping the top 10% non-EVT to EVT-capable in all states. Bypassing non-EVT centers by 15 minutes resulted in a 16.7% gain in coverage, reported the investigators in Stroke.