Acute Heart Failure, Hemoglobin Decrease Associated With Worse Outcome in Recent Study

Patients with acute heart failure have been shown to have a greater risk of both hospitalization and all-cause mortality following the occurrence of at least 1 acute anemic episode, or a drop in hemoglobin (Hb) levels exceeding 30%, according to the results of a study out of Spain published in Journal of Clinical Medicine.

“Well-established as a prognostic factor, the prevalence [of anemia] is more than 25% in all patients with heart failure and even greater in older adults,” the study authors said. “Moreover, a progressive reduction of hemoglobin (Hb) implies a poor prognosis.” However, how much of an impact significant Hb drops have on outcomes in patients with heart failure has not been investigated, they noted, and that served as the basis of their study.

Their total study population comprised 45,437 patients being treated for heart failure who were tested for and had their Hb levels recorded between January 1, 2012, and December 31, 1026. More than half (54.9%) were female, the mean (SD) age was 74.3 (11.0) years, and the average follow-up was 2.9 years. Their data were obtained from the electronic health records of the Valencian Health Agency’s ABUCASIS and corroborated by hospital records.

The study results demonstrate that 6.4% of study enrollees had at least 1 Hb fall, 0.3% had 2 or more Hb falls, and 0.8% had concomitant acute kidney injury (AKI). Episodes of Hb falls totaled 3512 for 3373 patients, or 2.8 per 100 patients with heart failure each year and happened more among the male study subjects.

Risk of hospitalization, however, increased across the board, after the first episode of anemia, for the 10.3% (3.6/100 patients with heart failure/year) of patients who experienced acute heart failure over the course of the study, with each of the 3 measures:

• 1 Hb fall: HR, 1.30 (95% CI, 1.19-1.43)
• 2 or more Hb falls: HR, 1.59 (95% CI, 1.14-2.23)
• Concomitant AKI: HR, 1.61 (95% CI, 1.27-2.03)

In addition, 10,490 patients died overall (7.4/100 patients with heart failure/year) during the study. This group had 9037 Hb fall episodes, which broken out equate to 2.6% with at least 1 episode, 0.1% with 2 or more, and 0.3% with concomitant AKI. A drop in Hb levels was again associated with inferior outcomes, this time for all-cause mortality, for the 3 measures:

• 1 Hb fall: HR, 2.20 (95% CI, 2.06-2.35)
• 2 or more Hb falls: HR, 3.14 (95% CI, 2.48-3.97)
• Concomitant AKI: HR, 3.20 (95% CI, 2.73-3.75)

Baseline Hb levels were also significantly lower, up to 20%, among the groups with 2 or more Hb falls and with AKI compared with the people who did not have an anemic episode: 10.2 to 11.4 g/dL compared with 12.8 g/dL, respectively. Also in the Hb falls/AKI group, the baseline mean (SD) glomerular filtration rate was significantly lower compared with the overall result: 48.5 (27.2) vs 64.1 (23.3) mL/min/1.73 m².

“Patients with heart failure are at risk of developing AKI, due to a low cardiac output or congestive status, as well as the use of drugs blocking the renin-angiotensin system or diuretics. In an AKI condition, Hb falls is an accompanying element, mainly in the most severe classes, and increase the burden to the heart,” the investigators concluded.

With the incidence of heart failure on the rise, and hospitalizations for the condition as a results, the authors caution clinicians to be more vigilant in cases accompanied by anemia.

Reference

Lopez C, Holgado JL, Fernandez A, et al. Impact of acute hemoglobin falls in heart failure patients: a population study. J Clin Med. Published online June 15, 2020. doi:10.3390/jcm9061869