OBJECTIVE: This study aimed to determine whether any change occurred over time in level of evidence (LoE) of therapeutic interventions supporting heart failure (HF) and other European Society of Cardiology guideline recommendations.
RESULTS: We selected topics with at least three documents released between 2008 and April 2022. Classes of recommendations (CoR) and supporting LoE related to therapeutic interventions within each document were collected and compared over time. A total of 1822 recommendations from 18 documents on 6 topics [median number per document = 112, 867 (48%) CoR I] were included in the analysis. There was a trend towards a reduction over time in the percentage of CoR I in HF (46-36-34%), non-ST elevation myocardial infarction (NSTEMI; 78-58-54%), and pulmonary embolism (PE; 65-50-39%) guidelines, with a decrease in the total number of recommendations for HF only. Percentage of CoR I was stable over time around 40% for valvular heart disease (VHD) and atrial fibrillation (AF), and around 60% for cardiovascular prevention (CVP), with an increase in the total number of recommendations for VHD and CVP and a decrease for AF. Among CoR I, 319 (37%) were supported by LoE A, with a decrease over time for HF (56-46-42%), an increase for NSTEMI (29-38-48%) and AF (28-31-36%), a bimodal distribution for PE and CVP, and a lack for VHD.
CONCLUSIONS: LoE supporting therapeutic recommendations in contemporary European guidelines is generally low. Physicians should be aware of these limitations, and scientific societies promote a greater understanding of their significance and drive future research directions.