Heart failure and anemia: Effects on prognostic variables

Anemia is frequent in heart failure (HF), and it is associated with higher mortality. The predictive power of established HF prognostic parameters in anemic HF patients is unknown.

Clinical, laboratory, echocardiographic and cardiopulmonary-exercise-test (CPET) data were analyzed in 3913 HF patients grouped according to hemoglobin (Hb) values. 248 (6%), 857 (22%), 2160 (55%) and 648 (17%) patients had very low (<11g/dL), low (11-12 for females, 11-13 for males), normal (12-15 for females, 13-15 for males) and high (>15) Hb, respectively.

Median follow-up was 1363days (606-1883). CPETs were always performed safely. Hb was related to prognosis (Hazard ratio (HR)=0.864). No prognostic difference was observed between normal and high Hb groups. Peak oxygen consumption (VO₂), ventilatory efficiency (VE/VCO₂ slope), plasma sodium concentration, ejection fraction (LVEF), kidney function and Hb were independently related to prognosis in the entire population. Considering Hb groups separately, peakVO₂ (very low Hb HR=0.549, low Hb HR=0.613, normal Hb HR=0.618, high Hb HR=0.542) and LVEF (very low Hb HR=0.49, low Hb HR=0.692, normal Hb HR=0.697, high Hb HR=0.694) maintained their prognostic roles. High VE/VCO₂ slope was associated with poor prognosis only in patients with low and normal Hb.

Anemic HF patients have a worse prognosis, but CPET can be safely performed. PeakVO₂ and LVEF, but not VE/VCO₂ slope, maintain their prognostic power also in HF patients with Hb<11g/dL, suggesting CPET use and a multiparametric approach in HF patients with low Hb. However, the prognostic effect of an anemia-oriented follow-up is unknown.