Low-Level Vitamin D Is Associated with Atrial Fibrillation in Patients with Chronic Heart Failure.

Abstract

Atrial fibrillation (AF) frequently accompanies heart failure (HF), and causes exacerbation of symptoms and treatment failure in such patients. Vitamin D was recently suggested to be an important mediator of cardiovascular disease, including HF. The aim of this study was to evaluate the relationship between vitamin D deficiency and AF in patients with chronic HF. The study included 180 chronic HF patients that were divided into 2 groups based on having sinus rhythm [AF (-) group] or chronic AF [AF (+) group]. Vitamin D status was assessed via measurement of the serum 25-hydroxyvitamin D (25[OH]D) concentration. Mean age of the patients was 66 ± 8.7 years and 53.9% were male. There weren't any significant differences in age, gender, body mass index, etiology or chronic HF stage between the 2 groups. The vitamin D level in the AF (+) group was significantly lower than in the AF (-) group (11.05 ng/mL vs. 20 ng/mL, p < 0.001) and the parathyroid hormone level was significantly higher in the AF (+) group (76.7 vs. 55 pq mL, p < 0.001). The left atrium to body surface area ratio (LA/BSA) was significantly higher in the AF (+) group (45.03 mm/m2 vs. 42.05 mm/m2, p < 0.01). Independent predictors (based on multiple regression) of AF were vitamin D level (OR = 0.854, 95% CI: 0.805-0.907, p < 0.001) and LA/BSA ratio (OR = 1.077, 95% CI: 1.003-1.156, p < 0.05). The optimal vitamin D cut-off value for the prediction of AF was 16.50 ng/mL, with a sensitivity of 76.0% and specificity of 65.5% (AUC = 0.75, 95% CI: 0.67-0.82). A low plasma vitamin D concentration was strongly associated with AF in patients with chronic HF.