Iron deficiency and hematinic deficiencies in atrial fibrillation: A new insight into comorbidities

Iron deficiency (ID) is the most common nutritional deficiency, and iron metabolism becomes further deteriorated in the presence of certain conditions, such as heart failure (HF). Atrial fibrillation (AF) has many similarities to HF, including a chronic inflammatory pathophysiology; however, the prevalence of ID and other hematinic deficiencies in AF patients have not been determined.

In this study, the prevalence of iron (serum ferritin <100 µg/L or ferritin 100-299 µg/L with transferrin saturation <20%), vitamin B12 (<200 pg/mL), and folate deficiency (<4.0 ng/mL) was evaluated in 101 patients with non-valvular AF with preserved left ventricular ejection fraction and no signs of HF, and the results were compared with 35 age- and gender-matched controls.

Anemia was detected in 26% of the patients. A total of 48 (47.6%) patients had ID, 10 (9.9%) had a vitamin B12 deficiency, and 13 (12.9%) had a folate deficiency. The prevalence of ID was similar in the controls and the paroxysmal AF patients, but increased gradually in persistent and permanent AF. Univariate logistic regression analysis demonstrated that permanent vs. paroxysmal AF [Odds ratio (OR): 2.17; 95% confidence interval (CI): 0.82-5.69; p=0.011], high sensitive C-reactive protein (OR: 1.47; 95% CI: 0.93-2.36; p=0.019), N-terminal pro b-type natriuretic peptide (OR: 1.24; 95% CI: 0.96-1.71; p=0.034), and white blood cell count (OR: 1.21; 95% CI: 0.95-1.58; p=0.041) were associated with ID. In multivariable analysis, permanent AF remained as an independent clinical associate of ID (OR: 4.30; 95% CI: 0.83-12.07; p=0.039).

ID is common in permanent AF, as in HF. Inflammation and neurohormonal activation seem to contribute to its development.