Impact of prophylactic corticosteroids on systemic inflammation after extensive atrial ablation in pigs

Prophylactic corticosteroids have been reported to attenuate the increase in C-reactive protein (CRP) and the incidence of atrial fibrillation (AF) both after heart surgery and AF ablation. We tested the impact of a single prophylactic corticosteroid dose on ultrasensitive CRP 24 h and 14 days after extensive linear atrial ablation (8 mm or 3.5 irrigated tip) guided by electroanatomical mapping (NavX) in pigs with normal hearts.

Pigs (n= 19; 35 kg) were divided into three groups: corticoid (n= 7), atrial ablation with administration of 500 mg methylprednisolone intravenous at anaesthetic induction; control (n= 7), atrial ablation only; and sham (n= 5), surgical procedure without ablation. Troponin and CRP were measured before, 24 h and 14 days after the procedure. After sacrifice, lesions were analysed macroscopically and histologically. Linear lesions were created in the right (n= 23) and left (n= 21) atrium of 14 animals, with no difference between groups. In all groups there was elevation of troponin and CRP 24 h after ablation, with a return to baseline values after 14 days. However, CRP levels of the control, corticoid, and sham groups were similar at all three time points analysed (baseline P= 0.52, 24 h P= 0.21, 14 days P= 0.66). Histological analysis did not show any difference between corticoid and control groups.

In this model, extensive biatrial RF ablation, per se, does not promote systemic inflammation. The use of a prophylactic single corticoid dose before ablation did not prevent systemic inflammation or alter the healing of the lesions.