Rigour of Development of European Society of Cardiology, American College of Cardiology and American Heart Association guidelines over a 12-year period (2013-2024): a systematic review of guidelines

Introduction: The ESC and ACC/AHA regularly publish guidelines for the management of cardiovascular disease. By definition, a guideline should follow strict methodological criteria, and have a transparent, traceable and reproducible development process. We aimed to assess the overall strength of the recommendations and rigour of methodological development in ESC and ACC/AHA guidelines.

Methods: A systematic review of the ESC and ACC/AHA guidelines published from 2013 to 2024 was conducted. Documents Class of Recommendation (COR) and Level of Evidence (LOE) of recommendations were included. For each document, data regarding citation count (ISI and Scholar), and COR and LOE of the recommendations were extracted. Guidelines were assessed for rigour of methodological development using the Appraisal of Guidelines for Research & Evaluation II (AGREE II) instrument.

Results: Among the 76 included guidelines, the average citation-per-year was 344 (ISI) and 681 (Scholar). Forty-nine % of the recommendations were classified as COR I (strong recommendations), while 46% were based solely on expert opinion (LOE C). The overall AGREE II methodology domain score was 29 ± 6 (range 7-56), with lowest performance for the domains of systematic search of evidence, use of predefined criteria for selecting the evidence and external review. Both the strength of the recommendations and rigour of development showed a stable trend over the past 12 years. The ACC/AHA guidelines followed more rigorous development methods compared to ESC (AGREE II 36±3 vs. 24 ± 3).

Conclusions: Clinical guidelines from the main European and American cardiovascular societies are highly cited but show significant limitations in methodological rigour.