Systolic blood pressure on admission as a marker of fluid re-distribution in acute heart failure

Abstract

Background: The relation between systolic blood pressure (sBP) on admission and the extent of fluid re-distribution in patients with acute heart failure (AHF) remains unclear. This study aimed to investigate this relation.

Methods: We enrolled consecutive patients who were admitted for AHF in our cardiology department and divided them into three groups according to the tertiles of sBP on admission as follows: low, intermediate, and high sBP groups. Weight changes and estimated relative plasma volume changes (ΔePV) on admission and 24h later were determined in each patient. ΔePV were calculated with the Strauss formula using hemoglobin and hematocrit levels. Univariate and multiple regression analyses were performed to investigate the relation between sBP and ΔePV.

Results: The ΔePV of low, intermediate, and high sBP groups were 104.3%, 108.2%, and 121.3%, respectively. High sBP group showed a significantly larger ΔePV than the other two groups (p<0.001 and 0.004, respectively). The body weight of patients in the high sBP group slightly but significantly decreased within 24h (-0.64±0.92kg, p=0.002). The initial sBP had a significant correlation with ΔePV (R², 0.295; p<0.001). Multiple regression analysis showed significant association between initial sBP with ΔePV.

Conclusions: These results indicate that large amounts of extravasated fluid existed on admission in patients with a high initial sBP. The sBP on admission could be a simple and useful indicator for the extent of fluid re-distribution in AHF.

Keywords: Acute heart failure; Blood pressure; Clinical scenario; Fluid re-distribution; Plasma volume.