When this analysis was repeated using the data available from all patients with a 2-year follow-up (n = 83), multivariate analysis identified high-gradient AS (peak velocity ≧4 m/sec) and absence of CKD as independent predictors of Hb-recovery, whereas blood transfusion was no longer significantly associated with a reduced likelihood of Hb-recovery (Table 2). This evidence concerns the gene GSTM1 and chronic kidney disease.