The Association between Hematocrit and All-Cause Mortality in Patients with Acute Congestive Heart Failure

A Retrospective Cohort Study

Abstract

Hematocrit (HCT) has clinical significance in the prognosis of acute heart failure (AHF). This study investigated the association between HCT and 365-day all-cause mortality rate from the MIMIC-IV database. We also explored the specific inflection point for HCT that affects the varying clinical prognoses in patients with AHF.

A total of 2,193 patients with AHF were extracted from the MIMIC-IV database. Patients were divided into 3 groups based on HCT levels at admission: low-HCT (< 30%), middle-HCT (30% - 40%), and high-HCT groups (≥ 40%). Ten variables were identified using the least absolute shrinkage and selection operator regression. In multivariable Cox regression, HCT was identified as an independent protective factor for 365-day all-cause mortality in patients with AHF (HR = 0.98, P = 0.004). The restricted cubic spline curve revealed a nonlinear relationship between the 2 (P nonlinear = 0.002), with inflection points at 30. According to the threshold effect analysis of HCT on mortality, patients in the low HCT group had a significantly higher mortality rate (HR = 0.92, P = 0.001). Finally, subgroup analysis revealed no interaction (P > 0.05).

A negative association exists between HCT and 365-day all-cause mortality in patients with AHF. Low HCT (< 30%) was significantly associated with a higher mortality rate in patients with AHF.