Abstract

INTRODUCTION: The prognostic effect of the direction of change in sodium (Na) level from admission to subsequent check in patients with acute heart failure (HF) has not been previously explored. METHODS: The ESCAPE trial data was utilized to study whether the rise of 1^st follow-up Na (at day 3) relative to admission (among patients with admission hyponatremia) is associated with favorable outcomes. The study endpoints were all-cause rehospitalization and a composite of death, rehospitalization and cardiac transplant, both up to 6-month after discharge. RESULTS: Patients with rise of 1^st follow-up Na (n = 43) had an average admission Na of 130.1 meq/L which increased to 134 meq/L at day 3 (P < 0.001), while patients without rise of 1^st follow up Na (n = 46) had an admission Na of 131 meq/L which decreased to 128.9 meq/L at day 3 (P < 0.001). There was an inverse association between the magnitude of change in Na level from admission to day 3 and the magnitude of change in blood urea nitrogen (BUN, r = -0.304, P = 0.004), creatinine (r = -0.401, P < 0.001) and weight (r = -0.279, P = 0.011) during the same time frame. Among those 89 cases, 56 (63%) were rehospitalized and 70 (79%) experienced the composite endpoint. Patients without rise in 1^st follow-up Na had higher frequency of rehospitalization (76.1% vs. 48.8%, univariate Odds ratio (OR) 1.778, 95% CI 1.174-2.693, P = 0.009) and composite endpoint (89.1% vs. 67.4%, univariate OR 1.779, 95% CI 1.208-2.619, P = 0.017), compared with those with Na rise. Cox regression analysis showed that rise in 1^st follow-up Na was independently associated with reduced rehospitalization (Hazard ratio (HR) 0.429, 95% CI 0.191-0.960, P = 0.04) and the composite endpoint (HR 0.430, 95% CI 0.201-0.920, P = 0.03) after covariate adjustment. CONCLUSION: Rise of first follow-up Na in patients with HF decompensation and hyponatremia on admission is associated with favorable intermediate-term outcomes.