Hypochloremia as a predictor of In Hospital Outcome in Patients with Acute Decompensated Heart Failure

Heart failure (HF) is a major health problem in India with a post admission mortality of 20%–30%.[2

HF is one of the leading causes of hospitalization for patients aged 65 and above.

Most of the literature in HF till recently has primarily focused on hyponatremia as the major predictor of short and long-term morbidity and mortality.

Historically, sodium alone has been considered as the major contributor to volume homeostasis, and limited research attention has been given to chloride, a major extracellular anion that is abundantly present in intravascular and interstitial compartments and that counterbalances the positive charges of sodium.

Several studies have found that the single best predictor of mortality was an elevated blood urea nitrogen (>43 mg/dl), followed by low systolic blood pressure (<115mm Hg) and high serum creatinine (>2.75mg/dl), additional factors being presence of congestion, reduced left ventricular ejection fraction (LVEF), ischemic etiology, anemia, elevated natriuretic peptide levels.

Recent epidemiological studies have implicated chloride, rather than sodium, as the driver and predictor of poor survival previously attributed to hyponatremia in heart failure.

DESCRIPTION

Patients with diagnosis of acute decompensated heart failure admitted in Kasturba Hospital, In Department of Medicine and Department Of Cardiology in Wards, HDUs,ICUs will be divided into tertiles based on admission chloride levels.

 The following details of all patients will be included in the study.

 Age, sex, demographic data and comorbidities.

 History with particular emphasis on treatment history and cardiac symptomatology before admission and through the course of hospital stay.

 Physical examination with focus on weight, jugular venous pressure (JVP), pedal edema, cardiac auscultation.

 Investigations to be done:  echocardiography, Serum electrolytes, Serum uric acid, NT pro BNP, Renal Function Test (RFT), Liver Function Test (LFT), Complete Blood Count (CBC).

All the quantitative parameters such as age of patient and length of stay , serum chloride level,serum potassium, serum urea, serum creatinine, haemoglobin levels, ejection fraction( EF%) and serum sodium levels will be expressed as mean and standard deviation or median with interquartile range in case of  non-normality of data.

 Categorical variables, such as gender, presence of diabetes mellitus, hypertension, smoking, etc. will be presented as percentages. The differences in the mean values of various parameters such as mean length of stay, blood urea nitrogen, serum potassium, sodium, uric acid, NT pro BNP, etc. amongst different serum chloride levels will be tested for statistical significance by analysis of variance or by non-parametric test of significance in case of non-normality of the data.

 The relationship between the length of stay and serum chloride levels will be assessed by estimating correlation coefficient. Multiple correlational coefficient will also be calculated to evaluate the relationship of serum chloride levels with length of stay considering the other confounding factors such as blood urea nitrogen, serum potassium, sodium, uric acid, NT pro BNP.

 Differences in mean or median values between the two groups such as serum chloride <96meq/L, >101 meq/L will be tested for statistical significance by Student –t test or Mann-Whitney test in case of non-normality of the data. Similarly, association of various qualitative variables such as presence of various comorbidities with different groups of serum chloride levels will be tested for statistical significance by Chi-Square test of significance.