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

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.