Hypochloremia in chronic and acute heart failure scenarios: Prevalence and risk factors

Eur J Intern Med. 2025 Jun 10:S0953-6205(25)00215-8. doi: 10.1016/j.ejim.2025.05.022. Online ahead of print.

Abstract

Aims: Chloride plays a key role in maintaining volume homeostasis. Low plasmatic chloride levels are associated with diuretic resistance and worse outcomes in patients with heart failure (HF). This study focused on determining the prevalence and factors related to hypochloremia in patients with heart failure (HF) in chronic and acute settings.

Methods: We conducted a retrospective analysis of three cohorts: chronic HF patients from the Spanish Cardiorenal Registry, ambulatory patients with worsening heart failure (WHF) from the SALT-HF trial, and inpatient WHF admitted in a teaching-level center in Spain. Multivariate linear regression analyses were employed to identify factors associated with chloremia.

Results: The chronic HF cohort included 845 patients [median age 75 years, 38 % female, 62.7 % presenting with a left ventricular ejection fraction (LVEF)≤40 %]. The prevalence of hypochloremia was 5.5 %. The second cohort (ambulatory WHF) comprised 148 participants (median age 80 years, 30 % female, 50 % displaying LVEF ≥ 50 %). Here, hypochloremia was observed in 11 % of the sample. The third cohort (inpatient WHF) enrolled 427 patients (median age 87 years, 64 % female, 82 % with LVEF≥50 %). This group showed a hypochloremia prevalence of 24 %. Multivariate analysis identified lower plasma sodium, loop diuretic treatment, and higher CA125 as common factors independently related to lower chloride levels in the three cohorts.

Conclusions: Prevalence of hypochloremia in HF differ across clinical status. Lower chloride is associated with lower sodium levels, prior loop diuretic and thiazide treatment, and higher CA125 values.

Keywords: Chloride; Heart failure; Hypochloremia.