Twenty years of ESC heart failure guidelines: evolution of recommendation strength and evidence quality

Introduction Over the past two decades, major advances in the understanding and management of heart failure (HF) have contributed to meaningful reductions in HF-related morbidity and mortality. We sought to evaluate temporal trends in both the strength and quality of recommendations issued in the European Society of Cardiology (ESC) Heart Failure Guidelines over the last 20 years. Methods We assessed recommendation strength by analysing the relative proportions of Class of Recommendation (COR) I and III statements, and evaluated evidence quality by examining the proportions of Level of Evidence (LOE) A and B recommendations. All ESC HF Guidelines published within the past two decades were reviewed, with the 2021 ESC HF Guidelines—incorporating the 2023 Focused Update—representing the most recent version included. Results Five guideline editions were analysed: 2008, 2012, 2016, 2021, and the 2021 Guidelines with the 2023 Focused Update. The proportion of strong recommendations (COR I or III) ranged from 48% in 2021 to 65% in 2012. Evidence quality (LOE A or B) ranged from 47% in 2008 to 58% in 2012. In the most recent guideline iteration, evidence quality was substantially higher for therapeutic compared with diagnostic recommendations (63% vs. 19%, p < 0.001). No significant differences were observed in recommendation strength between treatment and diagnostic sections, nor in strength or evidence quality between chronic and acute HF recommendations. Conclusions Despite notable scientific and clinical progress in HF management over the past two decades, neither the strength nor the quality of recommendations in ESC HF Guidelines has shown meaningful improvement. These findings underscore the ongoing need for high-quality research to address persistent evidence gaps in the field.