BACKGROUND & AIMS: Impairment in nutritional status (i.e. malnutrition) can significantly affect the progression and prognosis of patients with heart failure (HF). However, systematic evidence synthesizing its prevalence using new tools and associations with clinical outcomes remains insufficient. Therefore, this study aimed to systematically review the prevalence of malnutrition and its association with adverse clinical outcomes in patients with HF.

METHODS

We conducted a systematic review of observational studies identified in four databases (Pubmed, Embase, Web of Science and Scopus), without date or language restrictions. Studies reporting data on malnutrition diagnosis from any integrative tool, and its association with predefined clinical outcomes in HF patients were included. Outcomes of interest were mortality, disease exacerbation, quality of life, physical function, and length of hospital stay. The screening process (Rayyan®) and the data extraction (Redcap®) were independently conducted by two reviewers. Disagreements were solved by a third reviewer. Risk of bias in primary studies was assessed by New-Castle Ottawa scale. Certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Publication bias was explored. A meta-analysis with a random-effects model was performed to combine data using R software. Heterogeneity was explored by subgroup analyses.

RESULTS

Ninety one studies were included [38.4% conducted in Japan, 79.1% involving inpatients, 59.3% of with Controlling Nutritional Status (CONUT) score]. Pooled data (n = 90 studies, 51,086 patients) estimated the prevalence of malnutrition at 44.6% (95% CI, 37.7-51.7%; I 99.1%). This prevalence was higher in studies evaluating inpatients compared to outpatients (49.3 vs 27.1%) and in studies using the CONUT score rather than the Mini Nutritional Assessment (MNA) (60.5 vs 15.7%). Malnutrition was associated with higher risk of mortality (n = 28 studies, 23,163 patients; RR = 2.02, 95% CI 1.53-2.67; I² = 88.3%), and prolonged hospitalization (n = 7 studies, 4803 patients; RR = 2.14, 95% CI 1.83-2.50; I² = 0.0%), without differences in the subgroup analyses. The heterogeneity and small number of studies precluded a meta-analysis of the other outcomes. 33.3% of studies had high risk of bias. For all outcomes, the certainty of evidence was very low.

CONCLUSIONS

Malnutrition is a prevalent concern among patients with HF, increasing the risk of worse outcomes. The high risk of bias in primary studies and the incomplete explained heterogeneity graded the certainty of evidence as very low. Taken together, caution is necessary in interpreting our findings.

REGISTRATION

Internal Prospective Register of Systematic Reviews (PROSPERO registration code: CRD42024506372).