Not all anemia is the same: Distinct in-hospital hemoglobin patterns and prognosis in HFpEF and HFrEF - Insights from the SAKURA-HF registry.

BACKGROUND

Anemia is common in heart failure (HF), but the prognostic significance of in-hospital hemoglobin (Hb) changes remains unclear. We evaluated whether Hb trajectories during hospitalization for acute HF predict post-discharge outcomes using the Academic Research Consortium for High Bleeding Risk (ARC-HBR) anemia threshold of 11.0 g/dL.

METHODS

We analyzed 871 consecutive patients hospitalized for acute HF in the SAKURA-HF Registry (2020-2023). Patients were categorized according to admission and discharge Hb: Group 1, persistent anemia (<11.0 to <11.0 g/dL); Group 2, improved anemia (<11.0 to ≥11.0 g/dL); Group 3, new-onset anemia (≥11.0 to <11.0 g/dL); and Group 4, persistent non-anemia (≥11.0 to ≥11.0 g/dL). The primary endpoint was a composite of all-cause mortality or HF rehospitalization within 1 year after discharge. Kaplan-Meier analysis, log-rank testing, and Cox proportional hazards models were applied overall and by HF phenotype [HF with preserved ejection fraction (HFpEF) vs HF with mildly reduced or reduced EF (HFmrEF/HFrEF)].

RESULTS

During 1-year follow-up, 279 patients (32.0%) experienced the primary endpoint. Event rates differed significantly among groups (log-rank χ2 = 37.1, p < 0.001), with the highest incidence in Group 1 (48.6%). Compared with Group 4, Group 1 had an increased risk in univariable analysis [hazard ratio (HR) 2.28, 95% confidence interval (CI) 1.74-2.99] and remained independently associated with the endpoint (adjusted HR 1.80, 95% CI 1.09-2.97). In HFpEF, Group 1 was a strong independent predictor (adjusted HR 2.40, 95% CI 1.03-5.59), whereas in HFmrEF/HFrEF, associations observed in univariable analysis were attenuated after adjustment. Persistent anemia was more frequent in HFpEF than HFmrEF/HFrEF (28.5% vs 14.2%).

CONCLUSIONS

Persistent in-hospital anemia represents a strong independent predictor of 1-year adverse outcomes, particularly in HFpEF. In HFmrEF/HFrEF, Hb dynamics may instead act as a surrogate marker of congestion and renal dysfunction. Monitoring in-hospital Hb trajectories may facilitate phenotype-specific risk stratification.