Urinary chlorine at hospital admission as a predictor of diuretic resistance and clinical evolution in acute heart failure.

INTRODUCTION

The natriuresis measurement is useful to diagnose diuretic resistance (DR) and adjust furosemide doses in acute heart failure (AHF) hospitalized patients, but the utility of urinary chloride is unknown.

OBJECTIVES

To correlate the urine chloride at admission (UCLA) in AHF patients with the development of DR and cardiovascular (CV) events at the 180-day outpatient follow-up.

METHODOLOGY: A prospective study included patients hospitalized for AHF, without shock, creatinine >2.5 mg/dL or mechanical respiratory support at admission. They received 40 mg of intravenous furosemide at admission, UCLA was measured, and diuretic treatment was based on a protocol. DR was defined as the requirement for furosemide ≥240 mg/day, sequential nephron diuretic blocked (SNB), hypertonic saline serum, or renal replacement therapy.

RESULTS

116 patients were included, 51% were men, UCLA was 105 meq/L, and DR was developed in 17% of patients. The UCLA was associated with the development of DR (p 0.0001; AUC ROC curve 0.81; cut-off point 96 meq/L). UCLA <96 meq/L was associated with persistent congestion (p 0.01), furosemide ≥240 mg/day use (p 0.004), worsening of AHF (p 0.002) and renal function (p 0.02), use of SNB (p 0.001) and inotropic drugs (p 0.007), a longer hospital stay (p 0.02) and a higher CV death (p 0.05). At 180-day follow-up, UCLA <96 meq/L was associated with AHF readmissions (p 0.002).

CONCLUSION

In AHF hospitalized patients, low UCLA was associated with DR, persistent congestion, need for more aggressive decongestion strategies, worse in-hospital clinical outcomes and more AHF hospitalizations at 6 months.