BACKGROUND: Cardiac cachexia is a condition characterised by unintentional weight loss and muscle wasting in patients with heart failure. However, there is debate about the prognostic value of cardiac cachexia in these patients. OBJECTIVES: This meta-analysis aimed to evaluate the prognostic value of cardiac cachexia in patients who had heart failure. METHODS: We conducted a thorough literature search of the PubMed, Web of Science and Embase databases until 7 February 2025 to identify studies that examined the prognostic value of cardiac cachexia in patients with heart failure. The outcomes of interest were all-cause mortality and major adverse cardiovascular events (MACEs). The prognostic value of cachexia was determined by pooling the adjusted HR with a 95% CI. RESULTS: Nine studies, including 3821 patients with heart failure, met the inclusion criteria. Depending on the different definitions, the prevalence of cardiac cachexia varied from 11.2% to 37.8% in the included studies. A meta-analysis using a fixed-effects model showed that cardiac cachexia was associated with an increased risk of all-cause mortality (HR 1.59
95% CI 1.34 to 1.89) and MACEs (HR 2.41
95% CI 1.50 to 3.85). Subgroup analysis revealed that cardiac cachexia significantly predicted all-cause mortality, regardless of study design, heart failure subtypes, sample sizes, country, patients' age, definitions of cachexia, length of follow-up, baseline body mass index, left ventricular ejection fraction, and whether adjustment for renal function, smoking status, New York Heart Association class or heart failure medications was made. CONCLUSIONS: Cardiac cachexia is associated with a higher risk of all-cause mortality and MACEs in patients with heart failure. Assessing cardiac cachexia may provide valuable prognostic information for these patients.