C-reactive protein-to-albumin ratio and the mortality of patients with heart failure: a meta-analysis

The C-reactive protein-to-albumin ratio (CAR) reflects the interplay between systemic inflammation and nutritional status, and has recently been proposed as a prognostic biomarker in heart failure (HF). However, its association with mortality risk across acute decompensated HF (ADHF) and chronic HF (CHF) populations remains uncertain. This meta-analysis evaluated the relationship between baseline CAR and all-cause mortality in HF. PubMed, Embase, Web of Science, CNKI, and Wanfang were searched for relevant longitudinal studies. Risk ratios (RRs) were pooled using a random-effects model accounting for heterogeneity. Prespecified subgroup and meta-regression analyses were performed to evaluate the influence of study characteristics. Twelve cohort studies involving 6,377 patients were included. High CAR was associated with a significantly increased risk of mortality (RR = 2.34, 95% CI 1.86–2.93), with moderate heterogeneity (I² = 66%). Notably, the association was weaker in prospective studies (RR = 1.45) compared with retrospective studies (RR = 2.50). Subgroup findings were consistent across regions (Asian: RR = 2.62; Western: RR = 1.87), HF phenotype (ADHF: RR = 2.15; CHF: RR = 2.47), age (< 65 years: RR = 2.36; ≥65 years: RR = 2.33), CAR cutoff (< 0.5 mg/g: RR = 2.60; ≥0.5 mg/g: RR = 2.16), follow-up duration (< 30 months: RR = 2.20; ≥30 months: RR = 2.45), and analytic model (univariate: RR = 2.71; multivariate: RR = 1.99). Meta-regression identified no significant moderators. Elevated baseline CAR is consistently associated with higher mortality risk in patients with HF. However, the strength of this association appears lower in prospective studies, suggesting that the overall pooled estimate may be influenced by biases inherent to retrospective designs. In addition, the clinical utility of CAR for risk stratification of patients with HF requires further validation in well-designed prospective studies.