Anemia affects exercise capacity without compromising the benefits of cardiac rehabilitation in patients with heart failure

Introduction. Anemia in chronic heart failure (HF) patients is an independent predictor of mortality and its prevalence increases with the severity of HF.
Objectives. Prospectively assess the impact of hemoglobin (Hb) levels on the baseline exercise capacity and physical retraining results in patients with left ventricular systolic dysfunction.
Methods and material. We included 246 patients with heart failure of different etiologies with a mean age 56 ± 12 years with an ejection fraction <40%. All were considered anemic male patients with Hb <13 g/L and less than <12 g/L in women. All patients underwent a physical training program in cycloergometer with an average of 20 sessions.
Results. The 55.7% of patients was anemic. Hb rates did not differ before or after the rehabilitation program in any of the two groups.
The presence of anemia negatively influenced in exercise capacity measured by the exercise duration (5.08 ± 2.4 vs 5.9 ± 2.9 minutes, P=0.001), maximum load (68.3 ± 22.8 vs 80.2 ± 27.7 watts, p=0.0005) or peak oxygen consumption (14.9 ± 4.4 vs 16.9 ± 5.4 ml/kg/min, P=0.0001). The percentage gain in exercise capacity by training is comparable in both groups: 20.1 ± 22.1% and 18.9 ± 22.8%.
Conclusion. In patients with HF, anemia is responsible for metabolic, biochemical, and functional modifications, leading to a worsening of left ventricular dysfunction, a reduction of physical capacities and consequently deterioration in the quality of life. However, the rehabilitation benefits are similar in anemic and non anemic patients.

Keywords: Heart failure; Anemia; Hemoglobin; Baseline exercise capacity; Rehabilitation