The top tertile of hematocrit change during hospitalization is associated with lower risk of mortality in acute heart failure patients

Background: Hemoconcentration has been proposed as surrogate for changes in volume status among patients hospitalized with acute heart failure (AHF) and is associated with a favorable outcome. However, there is a dearth of research assessing the clinical outcomes of hospitalized patients with hemoconcentration, hemodilution and unchanged volume status. Methods: We enrolled 510 consecutive patients hospitalized for AHF from April 2011 to July 2015. Hematocrit (HCT) levels were measured at admission and either at discharge or on approximately the seventh day of admission. Patients were stratified by delta HCT tertitles into hemodilution ((increment)HCT ≤ - 1.6%), no change (NC, -1.6% < (increment)HCT ≤1.5%) and hemoconcentration ((increment)HCT >1.5%) groups. The endpoint was all-cause death, with a median follow-up duration of 18.9 months. Results: Hemoconcentration was associated with lower left ventricle ejection fraction, as compared with NC and hemodilution groups, while renal function at entry, New York Heart Association class IV, and in-hospital worsening renal function (WRF) were not significantly different across the three groups. After multivariable adjustment, hemoconcentration had a lower risk of mortality as compared with hemodilution [hazard ratio (HR) 0.39, 95% confidence interval (CI) 0.24-0.63, P < 0.001], or NC (HR 0.54, 95% CI 0.33-0.88, P = 0.015], while hemodilution and NC did not have significantly differ in mortality (HR 0.72, 95% CI 0.48-1.10, P = 0.130). Conclusions: In patients hospitalized with AHF, an increased HCT during hospitalization is associated with a lower risk of all-cause mortality than a decreased or unchanged HCT. Furthermore, all-cause mortality does not differ significantly between patients with unchanged and decreased HCT values.