Severity of anemia is correlated with the prevalence of left atrial low-voltage areas in patients with atrial fibrillation ablation

Background Although left atrial low-voltage areas (LVAs) are well-known indicator of atrial fibrosis and atrial fibrillation (AF) recurrence after catheter ablation, the association between anemia and prevalence of LVAs has not been clarified. We hypothesized that LVAs were more frequently found in patients with anemia than in those with normal hemoglobin levels. Purpose The purpose of this study was to investigate the association between hemoglobin levels and the prevalence of LVAs in patients with AF ablation. Methods In total, 1,473 (age, 68±10 years; female, 492 [33%]; persistent AF, 895 [61%]; CHA2DS2-VASc score, 2.5±1.5 points) consecutive patients who underwent initial AF ablation were enrolled in this study. Hemoglobin levels were measured before the ablation procedure, and anemia was defined as hemoglobin levels < 13.5 g/dL in male and < 12.0 g/dL in female. LVAs was defined as areas with bipolar voltage of <0.5 mV covered ≥5 cm² of left atrial surface area. Results Of 1,473 patients, LVAs existed in 348 (24%) patients. Hemoglobin levels was significantly lower in patients with LVAs than those without (13.4 ± 1.7 vs. 14.2 ± 1.5 g/dL, p <0.001). On classification by gender, only in male, hemoglobin levels were significantly lower in patients with LVAs than those without (Figure 1). The prevalence of LVAs increased with decreasing hemoglobin levels (Figure 2). On multivariate analysis including gender as a variable, anemia was an independent predictor of LVAs (odds ratio, 1.6; 95% confidence interval: 1.1–2.3; p=0.03). Conclusions The prevalence of LVAs increased with decreasing hemoglobin levels in patients with AF ablation. In particular, hemoglobin levels < 13.5 g/dL in male and < 12.0 g/dL in female was an independent predictor of LVA presence.