Impact of lifetime anaemia and iron control on outcomes in β-thalassaemia: Data from the longitudinal de-LIGHT study

Evidence on the impact of anaemia and iron control on morbidity and mortality in β-thalassaemia is limited to short-term studies assessing spot measures. We conducted a retrospective longitudinal cohort study of 557 patients with β-thalassaemia followed from diagnosis for a median of 38 years. There was a significant association between the lifetime proportion spent on transfusion and thalassaemia-related mortality (adjusted hazard ratios (HR) 0.987 for each 1-percent increase, p = 0.014). In both patients with non-transfusion-dependent β-thalassaemia (NTDT) and transfusion-dependent β-thalassaemia (TDT) (lifetime proportion on transfusion ≤70% and >70%, respectively), there was a significant association between a lifetime anaemia and iron control index (LAICI) and mortality (NTDT: adjusted HR 0.916 for each 1-point increase, p = 0.017; TDT: adjusted HR 0.672, p = 0.027). Survival was significantly lower in patients with suboptimal than optimal LAICI, defined based on international NTDT and TDT guidelines for anaemia and iron overload management (NTDT: adjusted HR 0.395, p = 0.046; TDT: adjusted HR 0.205, p = 0.020 for optimal vs. suboptimal LAICI). Patients with optimal LAICI had significantly lower odds of cardiac (NTDT, TDT), vascular (TDT), hepatic (NTDT), endocrine morbidity (NTDT, TDT) and osteoporosis (NTDT). Optimal anaemia and iron control throughout the entire disease course are essential to reduce morbidity and mortality in patients with β-thalassaemia.