LAUSR

AIM To determine what dietary interventions have been tested in HFpEF, the modulation method and outcomes employed and to summarise any evidence for benefit. METHODS AND RESULTS We performed key word searches in five bibliographic databases from 2001 to 2021, to identify randomised or experimental dietary interventions tested in HFpEF or mixed HF samples. Study characteristics were summarised according to PICO (population, intervention, comparator, outcome) categories and intervention complexity was assessed Twenty-five clinical investigations were retrieved; only ten (40%) were conducted exclusively in HFpEF; the remainder enrolled mixed HF samples. Most studies employed either highly tailored prescribed diets (n = 12, 48%) or dietary supplementation (n = 10, 40%) modalities. Dietary pattern interventions (n = 3, 12%) are less well represented in the literature. CONCLUSIONS Heterogeneity made pooling studies challenging. Better reporting of baseline characteristics and use of standardised HF lexicon would ensure greater confidence in interpretation of studies involving mixed HF populations. The field would benefit greatly from explicit reporting of the biological mechanism of action (e.g. the causal pathway) that an intervention is designed to modulate so that studies can be synthesised via their underlying mechanism of action by which diet may affect HF. An extension of the current set of core outcomes proposed by the European Society of Cardiology Heart Failure Association would ensure dietary clinical endpoints are more consistently defined and measured.