Shifts in Clinical Practice-Changing Acute Ischemic Stroke Research Over the Last Decade

The past decade has witnessed rapid growth of clinical-trial programs in Europe and Asia, with randomized clinical trials (RCTs) publications from these regions outpacing those of the U.S. However, limited data exist quantifying their relative influence on practice-defining results. Here, we evaluate these shifts by analyzing geographic origin, funding source, and clinical impact of practice-changing RCTs.

From the 2018 and 2026 American Heart Association/American Stroke Association (AHA/ASA) Acute Ischemic Stroke (AIS) Guidelines, we identified RCTs supporting new recommendations and extracted geographic origin (China/Europe/USA/Other), funding source (government/academic/non-profit vs. industry (private/mixed); NIH vs. non-NIH), and research topic (endovascular therapy (EVT), thrombolysis, imaging, poststroke care, and prehospital and systems of care). Analyses used unweighted, reference-density-weighted, and clinical-impact-weighted strategies. Temporal trends were assessed using the chi-square/Fisher's exact tests, with Rao-Scott adjusted chi-square tests accounting for weighting.

We identified 21 new recommendations (47 RCTs) in 2018 and 45 (89 RCTs) in 2026. In 2018, Europe led (51.1%), followed by the U.S. (31.9%), while China and other regions contributed minimally. By 2026, Europe remained first (36%), China rose to second (29.2%), and the U.S. declined to the smallest share (14.6%), across all weighted analyses (p<0.01). NIH-funded trials declined significantly from 21.3% (unweighted), 27.4% (reference-density-weighted), and 27.3% (clinical-impact-weighted) in 2018 to 4.5%, 4.8%, and 3.4%, respectively in 2026 (p<0.01 across all weighted strategies).

In this analysis, we identify a shift away from U.S.-based clinical trials and increasing contributions from China. U.S.-based RCTs fell from the second most cited to the least cited sources of practice-changing recommendations. NIH-funded research fell from nearly one-quarter in 2018 to <5% in 2026, highlighting increasing dependence on non-U.S. studies for U.S.-based care. These findings raise questions about the effectiveness of current AIS research paradigms in the U.S.