Abstract Objective The objective of this systematic review and meta-analysis was to assess sarcopenia and its components as prognostic factors in patients with heart failure (HF). Methods From inception to December 2022, a systematic literature search was carried out utilizing PubMed, Web of Science, Scopus, and Cochrane Library databases. A meta-analysis employing a random-effects model was performed to assess the pooled effects. Results The systematic review and meta-analysis included 32 and 18 longitudinal studies, respectively. The prediction of 1- to 2-year all-cause mortality in sarcopenia was not statistically significant (hazard ratio (HR): 1.35, 95% CI 0.76–2.38, I² = 54%, P = 0.31). The lowest combined quartile and quantile of the population were used to define low handgrip strength that showed identical results (HR: 1.24, 95% CI 0.94–1.62, I² = 0%, P = 0.13). Low L3-L4 psoas muscle mass (HR: 2.20, 95% CI 1.26–3.83, I² = 87%, P < 0.01) and slow gait speed (HR: 1.45, 95% CI 1.20–1.74, I² = 0%, P < 0.01) were significant contributors to all-cause mortality risk. Additionally, a 0.1 m/s increase in gait speed demonstrated a significant reduction of all-cause mortality (HR: 0.77, 95% CI 0.66–0.90, I2 = 60%, P < 0.01). Our narrative synthesis also described appendicular lean mass (ALM) and short physical performance battery (SPPB) scores as significant prognostic factors. Conclusions Compared to patients with higher overall functional performance, those with HF and low ALM, low psoas muscle mass, low SPPB, and slow gait speed are at an increased risk of all-cause mortality. Early prevention and/or treatment of lower limb physical function deterioration may be an essential strategy to reduce the risk of premature death in HF. Graphical abstract