Transfused patients had lower presenting Hb (87 vs. 105 g/L, p < 0.0001), higher rates of cardiac disease (29.4% vs. 12.9%, p = 0.009) and 5-azacytidine use (31.4% vs. 13.0%, p = 0.004). This evidence concerns the gene GSTM1 and heart disorder.