Transtubular potassium concentration gradient as a surrogate measure of arterial underfilling in acute decompensated heart failure

Abstract

Background: The monitoring of tissue hypoperfusion and the subsequent neurohumoral activation (ie, arterial underfilling) during decongestion is important for the management of acute decompensated heart failure (ADHF). The transtubular potassium concentration gradient (TTKG) has been reported to be a marker of renal aldosterone bioactivity. This study tested the hypothesis that TTKG can be a surrogate of arterial underfilling in patients with ADHF. Methods and Results: We measured TTKG at discharge in 100 ADHF patients. The primary outcome measure was the occurrence of tissue hypoperfusion events (defined according to the “Cold Modified 2014” definition criteria) within 1 month after discharge. The secondary outcome measure was the occurrence of cardiac death or ADHF readmission within 3 months after discharge. On receiver operating characteristic curve analysis, TTKG predicted tissue hypoperfusion events with high accuracy (C-statistic, 0.889) for a cut-off of 6.0. Multivariate Cox regression analyses demonstrated independent relationships between TTKG and both the primary and secondary outcomes. Conclusions: TTKG has utility as a surrogate of arterial underfilling, and spot TTKG at discharge may be a prognostic marker in ADHF patients.