Cross-Sectional Study Demonstrating Specificity of Iron Kinetics in Atrial Fibrillation.

Background: In the context of cardiovascular disease (CVD), iron metabolism assessment plays a pivotal role in the diagnosis of anemia and chronic inflammation. However, data regarding the prevalence of anemia, iron deficiency, and iron overload among outpatients in real-world clinical settings remain limited. Moreover, the influence of specific diseases on iron kinetics within the CVD spectrum has not been fully elucidated.

Methods And Results: We conducted a retrospective analysis of 260 patients attending a cardiology outpatient clinic who had undergone blood sampling for comprehensive evaluation of anemia and iron kinetics. The prevalence of anemia among these outpatients was 36.1%, but iron deficiency was observed in only 13.8% of patients (absolute iron deficiency: 1.5%). Notably, stored iron positively correlated with free iron in patients with sinus rhythm, but not in patients with atrial fibrillation (AF). Intriguingly, this relationship followed a similar pattern in the paroxysmal and longstanding AF subgroups. Moreover, multivariate regression analysis showed that iron dynamics significantly explained hemoglobin levels in patients with sinus rhythm but not in those with AF.

Conclusions: Although chronic inflammation may be a contributing factor, iron dynamics exhibited a distinct profile in patients with AF. The correlation between transferrin saturation and stored iron, evident in sinus rhythm patients, was abolished in AF, which supports the notion of chronic inflammation in patients with AF.