['In patients with chronic heart failure (HF), mortality is inversely related to haemoglobin (hgb) concentration. We investigated the prognostic importance of anaemia in patients with acute myocardial infarction (AMI) and left ventricular systolic dysfunction (LVSD) with and without HF.', 'We studied 1731 patients with AMI and left ventricular ejection fraction </=35% from the TRAndolapril Cardiac Evaluation (TRACE) study. Mild anaemia (110 g/L</=hgb<120 g/L in women and 120 g/L</=hgb<130 g/L in men) was present in 264 patients (15%), 114 (7%) had moderate (100 g/L</=hgb<110 g/L in women and 110 g/L</=hgb<120 g/L in men) and 59 (3%) had severe (hgb <100 g/L in women and <110 g/L in men) anaemia. According to the WHO criteria (hgb </=120 g/L in women and <130 g/L in men), 25% had anaemia. Anaemia was associated with increasing age, higher serum creatinine, lower body mass index, history of chronic HF, and worse NYHA class. In multivariable analyses including other prognostic factors only severe anaemia was associated with increased mortality, hazard ratio 1.59 (1.20-2.11). Anaemia was of prognostic importance in patients with HF, but not without HF. In HF patients the hazard ratios were 1.73 (1.26-2.36), 1.20 (0.93-1.56) and 1.05 (0.88-1.25) for severe, moderate and mild anaemia, respectively.'] Is anaemia an independent predictor of mortality in patients with left ventricular systolic dysfunction following acute myocardial infarction?