Impact of Acute Hemoglobin Falls in Heart Failure Patients: A Population Study

Abstract

Aims: This study assessed the impact of acute hemoglobin (Hb) falls in heart failure (HF) patients. Methods: HF patients with repeated Hb values over time were included. Falls in Hb greater than 30% were considered to represent an acute episode of anemia and the risk of hospitalization and all-cause mortality after the first episode was assessed. Results: In total, 45,437 HF patients (54.9% female, mean age 74.3 years) during a follow-up average of 2.9 years were analyzed. A total of 2892 (6.4%) patients had one episode of Hb falls, 139 (0.3%) had more than one episode, and 342 (0.8%) had concomitant acute kidney injury (AKI). Acute heart failure occurred in 4673 (10.3%) patients, representing 3.6/100 HF patients/year. The risk of hospitalization increased with one episode (Hazard Ratio = 1.30, 95% confidence interval (CI) 1.19-1.43), two or more episodes (HR = 1.59, 95% CI 1.14-2.23, and concurrent AKI (HR = 1.61, 95% CI 1.27-2.03). A total of 10,490 patients have died, representing 8.1/100 HF patients/year. The risk of mortality was HR = 2.20 (95% CI 2.06-2.35) for one episode, HR = 3.14 (95% CI 2.48-3.97) for two or more episodes, and HR = 3.20 (95% CI 2.73-3.75) with AKI. In the two or more episodes and AKI groups, Hb levels at the baseline were significantly lower (10.2-11.4 g/dL) than in the no episodes group (12.8 g/dL), and a higher and significant mortality in these subgroups was observed. Conclusions: Hb falls in heart failure patients identified those with a worse prognosis requiring a more careful evaluation and follow-up.

Keywords: acute kidney injury; anemia; blood loss; heart failure; hospitalization; mortality.

Figure 1

Cumulative risk of hospital admissions due to Acute Heart Failure by subgroup of patients with episodes of hemoglobin (Hb) fall with significant differences. No Hb fall (blue line): reference; one episode (yellow): HR = 1.30 (95% confidence interval (CI) 1.19–1.43); two or more (orange): HR = 1.59 (95% CI 1.14–2.23); and concomitant acute kidney injury (AKI) (green): HR = 1.61 (95% CI 1.27–2.03). Table number of subjects during the study.

Figure 2

Risk of all-cause mortality by subgroup of patients with episodes of Hb falls with significant differences. No Hb (blue line): reference; one episode (yellow): HR = 2.20 (95% CI 2.06–2.35); two or more episodes (orange): HR = 3.14 (95% CI 2.48–3.97); and concomitant AKI (green): HR = 3.20 (95% CI 2.73–3.75). Table number of subjects during the study.