Chloride Depletion Alkalosis as a Predictor of Inhospital Mortality in Patients with Decompensated Heart Failure

Abstract

Objectives: Chloride depletion alkalosis (CDA) is often seen as a consequence of diuresis in heart failure (HF) but its prognostic significance remains unknown. The purpose of this study was to evaluate the prognostic role of CDA in decompensated HF (DHF). Methods: A retrospective cohort analysis was performed on 674 patients who were admitted with DHF. Patients were assigned to 2 groups based on the change in serum bicarbonate (median = 3 mmol/l) after diuresis, which was calculated by computing the difference in the admission and discharge serum bicarbonate: the CDA group (a change in serum bicarbonate ≥3 mmol/l) and the non-CDA group (change in serum bicarbonate <3 mmol/l). The primary end points were inhospital mortality and the composite end point of all-cause 30-day mortality and hospital readmission for HF. Results: In a multivariable logistic regression model, the CDA group, i.e. 374 patients, had a lower inhospital mortality than the non-CDA group, i.e. 300 patients (OR 0.11, 95% CI 0.03-0.38; p = 0.0005) after adjusting for other covariates. There was no statistically significant difference in the combined end point of all-cause 30-day mortality and readmission between the 2 groups (OR 1.26, 95% CI 0.74-2.12; p = 0.39). Conclusion: The presence of CDA during hospitalization for DHF was independently associated with a better inhospital survival rate.