Prevalence and prognostic significance of anemia in patients with congestive heart failure treated with standard vs high doses of enalapril.
BACKGROUND
Anemia is common in patients with congestive heart failure (CHF), although its etiology and pathophysiology remain largely unexplained. The purpose of this study was to examine the prognostic significance of a low hematocrit (Hct) in patients with CHF and the possible role of angiotensin-converting enzyme inhibition in anemia development.


METHODS
Hct was measured at the time of enrollment of 160 patients with CHF, mean age 56 +/- 12 years, in New York Heart Association (NYHA) functional class 2.6 +/- 0.7 and with left ventricular ejection fraction of 20 +/- 9%. They were randomized to standard (mean: 17.9 +/- 4.3 mg/day) or high (mean: 42 +/- 19.3 mg/day) doses of enalapril. The follow-up duration was 2 years. Cox regression models were used to identify prognostic factors, and correlations among individual variables were tested.


RESULTS
Mean baseline Hct was 42.7 +/- 5%. In multivariate analyses, low Hct (p = 0.036), older age (p = 0.022) and low systolic blood pressure (p = 0.032) were independent predictors of death within 2 years. A correlation was found between baseline Hct and NYHA class (Spearman's correlation coefficient: -0.183, p = 0.008). A significant decrease in Hct from 43.2 +/- 4.9% at baseline to 40.7 +/- 4.4% at 2 years was observed in the group treated with high doses of enalapril (p < 0.001).


CONCLUSIONS
Low baseline Hct predicted poor 2-year prognosis in patients with CHF. Enalapril administered in high doses increased the incidence of anemia in this population. The underlying pathophysiologic mechanism and effects of maintaining a normal Hct on clinical outcomes remain to be determined.
Terrovitis
John V
JV
Heart Science Centre Harefield Hospital, Harefield, Middlesex, UK.
Anastasiou-Nana
Maria I
MI
Alexopoulos
George P
GP
Tsolakis
Elias J
EJ
Margari
Zafiria J
ZJ
Drakos
Stavros G
SG
Tsagalou
Eleftheria P
EP
Papazoglou
Panagiotis
P
Efentakis
Stylianos
S
Nanas
John N
JN
D000328:Adult; D000368:Aged; D000740:Anemia / Q000139:chemically induced* / Q000453:epidemiology; D004656:Enalapril / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D006333:Heart Failure / Q000150:complications* / Q000188:drug therapy*; D006400:Hematocrit; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis
D004656:Enalapril