Admission Serum Chloride Level Section as Predictor of Length of Stay in Acute Decompensated Heart Failure: A Prospective Observational Study

Introduction: Acute Decompensated Heart Failure (ADHF) frequently results in hospitalisation and is associated with significant morbidity. Recent evidence suggests that admission serum chloride levels may offer prognostic value beyond traditional markers such as sodium or natriuretic peptides. Aim: To assess the admission serum chloride level as predictor of length of stay in ADHF. Materials and Methods: This prospective observational study was conducted at the Department of General Medicine, Mahatma Gandhi Medical College and Research Institute, Puducherry, India, from August 2020 to May 2023, enrolled 60 adults (18-85 years) admitted with ADHF as defined by Modified Framingham criteria and Echocardiographic (ECHO) confirmation following ethical approval from the Institution. Informed consent was obtained from all participants. On admission, serum chloride and other blood parameters were measured. Serum chlorides levels were categorised as hypochloremia (<97 mEq/L), normochloremia (98-106 mEq/L), or hyperchloremia (≤107 mEq/L). The length of hospitalisation was recorded. The association between chloride and length of the stay was analysed using Analysis of Variance (ANOVA) in Statistical Package for Social Sciences (SPSS) version 25.0 and p-value <0.05 was considered significant. Results: The mean age of the participants were 62.7±10.8 years, with 60% males. Hypochloremia patients (n=11) had longer stays (13.09±1.58 days) than normochloremic (n=20; 7.75±1.97 days) and hyperchloremic (n=29; 4.90±1.35 days) (p-value <0.001) groups. Admission serum sodium (p-value=0.008) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) (p-value <0.001) varied significantly across chloride groups. There was strong negative correlation (r-value=-0.79; p-value <0.001) and the logistic regression showed that 1mEq/L increase in chloride cut the odds of prolonged stay by 53% (p-value=0.012) and confirms as a strong, independent predictor for length of hospital stay. Conclusion: Admission hypochloremia predicts prolonged hospitalisation in ADHF, supporting chloride assessment for risk stratification. Overall, serum chloride provides stronger prognostic information for ADHF than traditional markers.