Burden of Mild (<13 g/dl) Anemia in Patients With Atrial Fibrillation (A Report from a Multicenter Registry With Patient-Reported Outcomes)

The prognostic impact of anemia, especially mild anemia, in atrial fibrillation (AF) remains unclear. We examined clinical burdens of mild anemia on the quality of life (QoL) and clinical outcomes of 1,677 AF patients. Patients were divided into a non-anemia (hemoglobin [Hb] ≥13 g/dl for men and Hb ≥12 g/dl for women) and a mild anemia group (10≤ Hb <13 g/dl for men and 10≤ Hb <12 g/dl for women). At baseline, 22.5% of patients (n = 378) had anemia; patients in the mild anemia group had higher CHA₂DS₂-VASc scores (3.7 vs 2.7; p <0.01) and brain natriuretic peptide levels (253.5 vs 159.6 pg/ml; p <0.01) and were more likely to develop chronic kidney disease (64.2 vs 42.9%; p <0.01) than those in the non-anemia group. During follow-up (mean 1.7 ± 0.4 years), patients with mild anemia had a higher risk of heart failure hospitalization and major bleeding events than those without (12.2 vs 3.8%; p <0.01 and 5.6 vs 2.5%; p <0.01, respectively). Mild anemia was an independent risk factor for heart failure hospitalization (adjusted hazard ratio: 1.67, 95% confidence interval 1.06 to 2.62, p = 0.03) but not for major bleeding (adjusted hazard ratio: 1.44, 95% confidence interval 0.80 to 2.62, p = 0.23). QoL improvement was less likely in the mild anemia group during follow-up, despite the lack of significant differences at baseline. In conclusion, the presence of even mild anemia was associated with increased risks of heart failure hospitalization and poor QoL improvement.