A Cochrane review [Abstract] 1 included 11 studies with a total of 794 subjects. All participants had symptomatic chronic heart failure (CHF), left ventricular systolic dysfunction (LVEF<40%) and anaemia (mean haemoglobin levels of participants ranged from 10.1 to 11.8g/dL). All studies met the NYHA criteria for symptoms with a predominance of NYHA class III patients. Mean study duration was 6.3 months, ranging from 2 months to 12 months.
Compared to control, erythropoiesis-stimulating agents (ESA) treatment significantly improved exercise duration by 96.8 seconds (95% CI 5.2 to 188.4) and 6-minute walk distance by 69.3 metres (95% CI 17.0 to 121.7). Benefit was also noted in terms of peak VO2 (+2.29 mL/kg/min, 95% CI 0.62 to 3.95), NYHA class (-0.73, 95% CI -1.11 to -0.36), ejection fraction (+5.8%, 95% CI 2.43 to 9.11), B-type natriuretic peptide (-226.99 pg/mL, 95% CI -322.68 to -131.29) and quality-of-life indicators, with a mean increase in haemoglobin of 1.98 g/dL (95% CI 1.62 to 2.35). There was also a significantly lower rate of heart failure related hospitalisations (RR 0.62, 95% CI 0.44 to 0.87) and lower all-cause mortality (RR 0.61, 95% CI 0.37 to 0.99). No increase in adverse events with ESA therapy was observed, however studies were of small sample sizes and limited duration. There was substantial heterogeneity between the trials for exercise tolerance measures, change in haemoglobin level, NYHA class and LVEF. No evidence of heterogeneity was found for CHF-related hospitalisations, all-cause mortality or adverse effect outcomes.
Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment and lack of blinding) and by inconsistency (substantial heterogeneity between the trials; heterogeneity in participants and interventions).
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