The following is a summary of “Prognostic impact of serum chloride concentrations in acute heart failure patients: A systematic Rreview and meta-analysis,” published in the September 2023 issue of Emergency Medicine by Wu, et al.

For a meta-analysis, researchers sought to evaluate the incidence of hypochloremia and its impact on the prognosis of patients with acute heart failure (AHF), given its common occurrence in emergency departments and its association with electrolyte disorders, particularly focusing on chloride ion.

A comprehensive search was conducted in Cochrane Library, Web of Science, PubMed, and Embase databases for studies investigating the relationship between chloride ion and AHF prognosis up to December 29, 2021. Inclusion criteria were applied, and two researchers performed data extraction independently. The Newcastle-Ottawa Scale (NOS) assessed the quality of the included studies. Meta-analysis was carried out using Review Manager 5.4.1 software, with hazard ratios (HR) or relative risks (RR) and 95% CI as effect measures.

Seven studies involving 6,787 AHF patients were included in the meta-analysis. The incidence of hypochloremia in AHF patients at admission was found to be 17% (95% CI: 0.11–0.22). A reduction of one mmol/L in serum chloride at admission correlated with a 6% increased risk of all-cause death in AHF patients (HR = 1.06, 95% CI: 1.04–1.08, P < 0.00001). The hypochloremia group exhibited a 1.71 times increased risk of all-cause death compared to the non-hypochloremia group (RR = 1.71, 95% CI: 1.45–2.02, P < 0.00001). Moreover, the progressive hypochloremia group demonstrated a 2.24 times higher risk (HR = 2.24, 95% CI: 1.72–2.92, P < 0.00001), and the persistent hypochloremia group exhibited a 2.80 times higher risk of all-cause death (HR = 2.80, 95% CI: 2.10–3.72, P < 0.00001).

The evidence suggested that reduced chloride ion levels at admission are associated with a poor prognosis for AHF patients, with persistent hypochloremia indicating a worse prognosis. Caution was warranted in interpreting outcomes with limited data, such as progressive hypochloremia, persistent hypochloremia, and the composite of death + HF hospitalization, which are supported by only two studies in the literature.

Source: sciencedirect.com/science/article/abs/pii/S0735675723002851