BackgroundTo determine the optimal fluid resuscitation volume in septic patients with acutely decompensated heart failure (ADHF).MethodsSeptic patients with ADHF were identified from a tertiary urban medical center. The generalized additive models were used to explore the association between fluid resuscitation volume and endpoints, and the initial 3 h fluid resuscitation volume was divided into four groups according to this model: < 10 mL/kg group, ≥ 10 to ≤ 15 mL/kg group, > 15 to ≤ 20 mL/kg group, and > 20 mL/kg group. Logistic and Cox regression models were employed to explore the association between resuscitation volume and primary endpoint, in-hospital mortality, as well as secondary endpoints including 30-day mortality, 1-year mortality, invasive ventilation, and ICU admission.ResultsA total of 598 septic patients with a well-documented history of HF were enrolled in the study; 405 patients (68.8%) had sepsis-induced hypoperfusion. Patients with NYHA functional class III and IV were 494 (83.9%) and 22 (3.74%), respectively. Resuscitation volumes above 20 mL/kg (OR 3.19, 95% CI 1.31–8.15) or below 10 mL/kg (OR 2.33, 95% CI 1.14–5.20) significantly increased the risk of in-hospital mortality in septic patients, while resuscitation volumes between 15 and 20 mL/kg were not associated with the risk of in-hospital death in septic patients (OR 1.79, 95% CI 0.68–4.81). In the multivariable Cox models, the effect of resuscitation volume on 30-day and 1-year mortality in septic patients was similar to the effect on in-hospital mortality. Resuscitation volume exceeds 15 mL/kg significantly increased the risk of tracheal intubation, while fluid resuscitation volume was not associated with ICU admission in the septic patients. In septic patients with hypoperfusion, these fluid resuscitation volumes have similar effects on patient outcomes. This association was consistent across the three subgroups with worsened cardiac function, as well as in sensitivity analyses.ConclusionsOur study observed that an initial fluid resuscitation volume of 10–15 mL/kg in the first 3 h was optimal for early resuscitation in septic patients with ADHF, particularly those with worsened cardiac function. These results need to be confirmed in randomized controlled trials with larger sample sizes.