Abstract Body (Do not enter title and authors here): Background
Nearly one million individuals in the U.S. experience ischemic stroke annually and one-year recurrent stroke risk may exceed 10%. American Heart Association (AHA) Get-With-The-Guidelines-Stroke® Registry (GWTG-S) data suggests that up to 40% of stroke patients are discharged with an undocumented or cryptogenic etiology which may lead to suboptimal secondary prevention. Consequently, improved cardiology and neurology collaboration and evidence-based post-stroke evaluation may help identify stroke etiology, reduce recurrent stroke risk and improve outcomes.

Methods
In 2022, the AHA, in collaboration with HCA Healthcare and HCA Healthcare Foundation, designed and launched Getting to the Heart Of Stroke^TM (GTTHOS) in 10 HCA Healthcare comprehensive stroke centers to improve: 1) cardiology and neurology stroke care collaboration, 2) evidence-based post-stroke diagnostic evaluation and 3) assessment of social determinants of health and barriers to care. Components included a learning collaborative model, virtual performance improvement consultations, Plan-Do-Study-Acts, multidisciplinary teams, custom and existing GWTG-S metrics and performance improvement feedback.

Results
Using existing and custom GWTG-S data, GTTHOS centers increased rates of documented stroke etiology (58.06% vs. 48.63%), while decreasing cryptogenic stroke rates (31.01% vs. 34.89%) and lack of a documented stroke etiology (10.93% vs. 16.48%) (all comparisons on discharge, follow-up vs. baseline, p<0.0001). In addition, the use of evidence-based post-stroke diagnostic evaluation increased in GTTHOS centers, including intracranial vascular and carotid imaging, echocardiography, short-term and extended (surface, implantable) cardiac monitoring (Table).

Conclusion
In this novel AHA GTTHOS initiative in patients with stroke, which includes improved cardiology and neurology collaboration, rates of identified stroke etiology increased, while cryptogenic stroke and lack of a documented stroke etiology decreased. Furthermore, evidence-based post-stroke diagnostic evaluation, including imaging, echocardiography and short- and long-term surface and implantable cardiac monitoring, increased. These findings may contribute to improved outcomes.