Evolution and regional disparities in guideline recommendations and evidence levels for structural heart disease

Significant advances have been made in the field of structural heart disease (SHD), yet guideline characteristics and evolution across regions remain uncertain. This study aims to analyze the distribution of class of recommendation and level of evidence (LOE) of SHD guidelines across American College of Cardiology/American Heart Association (ACC/AHA), European Society of Cardiology (ESC), and Chinese cardiovascular societies. We evaluated 1,867 recommendations from prior and current guidelines. In current guidelines, strong recommendations (Class I/III) constituted 53.2%, yet only 8.1% (38/470) were supported by highest-quality evidence (LOE A). Regional variations existed, with ACC/AHA showing predominant LOE B recommendations (56.3%) while ESC and Chinese guidelines featured mainly LOE C (79.4% and 69.5%, respectively). Longitudinal analysis revealed overall evidence improvement. These findings highlight persistent challenges in aligning recommendation strength with evidence quality across healthcare systems. Additionally, the disparity across regions underlines the importance of establishing international collaborative mechanisms to coordinate guideline development processes.