Association of pre-ablation level of vitamin D with atrial fibrillation recurrence after catheter ablation: reply

Vitamin D was not involved in our article, because there had been no studies focusing on the association of vitamin D and atrial fibrillation (AF) recurrence after catheter ablation.¹

We surely agreed with the opinion of Levent et al. that it might be beneficial to exploring the role of pre-ablation vitamin D in evaluating the risk of post-ablation AF recurrence, because series of mechanism studies had indicated the role of vitamin D in the pathogenesis of AF.

But we disagreed with the pathological mechanism stated by Levent et al. (euw289). The mechanism we recognized was as follows: the antioxidant activity of vitamin D could inhibit reactive oxygen species production; reactive oxygen species could trigger AF due to the formation of the inflammation and proarrhythmic substrate. Besides, Vitamin D could negatively regulate RAAS, and angiotensin II might participate in the atrial structural and electrical remodeling.^2,3 Moreover, vitamin D could also modulate the calcium homeostasis and had a direct electromechanical effect.⁴ Besides, Levent et al. referred that vitamin D could up-regulate anti-inflammatory cytokines, but the effect was in immature dendritic cells,⁵ which had no relationship with AF.

Studies about vitamin D and post-ablation AF recurrence were still lacking. The results of epidemiologic studies about vitamin D deficiency and AF prevalence were still ambiguous.³ The study focusing on the role of vitamin D in preventing and terminating AF was still in the phase of animal testing, which was conducted in five rabbits with heart failure,⁴ therefore it is valuable and of great urgency to evaluate the role of vitamin D in AF occurrence and recurrence.

Conflict of interest: none declared.

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