INTRODUCTION
Acute heart failure (AHF) is the final consequence of a large number of
cardiovascular diseases and is one of the most important health care
problems in developed countries. The prevalence of AHF is increasing
with the aging of the
population1.
This disease causes relevant mordibity and mortality and is among the
main causes of hospitalization, hospital mortality and health care costs
in
Spain2,3,4,5,
with most hospital admissions being made through hospital emergency
departments (HEDs)6,7,8,9.
Although the role of anemia as a triggering factor of cardiac
decompensation is well known10, in the last years the
study of anemia in patients with heart failure (HF) has become the focus
of increasing interest due to its elevated prevalence and prognostic
implications. HF has been described as being associated with greater
hospitalization and with an increase in mortality in patients with a
reduced and preserved ejection
fraction11. The
prevalence of HF varies widely in the different studies available,
ranging from 4 to 55%, with one third of the patients presenting
decompensated HF12,13.This variability can be
explained by the different study populations selected and by the absence
of consensus in relation to the definition of anemia in the different
studies14, although when using the criteria of the
World Health Organization (WHO) (hemoglobin [Hb] < 12 g/dl
in women and < 13 g/dl in men), the prevalence is 30 % in
stable patients and 50% in decompensated hospitalized
patients15.
The cause of anemia in patients with HF is probably multifactorial.
Different mechanisms have been
described16:
reduction in intestinal iron absorption, increase in cytosines,
activation of the renin-angiotensin-aldosterone system, renal
dysfunction due to vasoconstriction and renal ischemia and loss of
erythropoietin and transferrin by the coexistence of proteinuria and
hematic losses related to antiaggregant or anticoagulant treatments.
Multiple observational studies have found that the presence of anemia
conditions a worse prognosis in patients with HF17, in
terms of mortality and readmission due to decompensation of HF. Data on
the impact of anemia on mortality in patients with AHF are scarce, and
the studies available are retrospective and usually include patients who
are hospitalized in conventional hospital wards. In a recent study
including 756 patients admitted for AHF, it was observed that Hb values
< 10 g/dL were significantly related to a greater mortality at
3 years, greater readmission at 30 days and longer hospital
stay18.
It has been reported that the use of iron and erythropoietin may be
beneficial in these patients. Silverberg and col19demonstrated that this treatment improved the ventricular ejection
fraction and functional capacity in a group of refractory HF patients.
The beneficial effect of the correction of anemia in this group of
patients was translated into a better quality of life, functional
capacity and lower rate of readmissions.
It is still not clear whether the association between anemia and the
outcomes of patients with AHF is causal or anemia is a marker of risk.
The favorable results of studies on the treatment of anemia together
with the harmful hemodynamic effects and the possibilty that it favors
myocardial ischemia support a cause-effect relationship. Therefore, the
main aim of this study was to evaluate the effect of anemia on
short-term mortality (30 days) and at one year in patients with AHF and
determine the implication of anemia in progressive mortality from
patient inclusion until one year of follow-up.