PPARγ agonist use and recurrence of atrial fibrillation after successful electrical cardioversion

Inflammation is associated with atrial fibrillation (AF), and peroxisome proliferator-activated receptor-gamma (PPARγ) agonists have anti-inflammatory properties. We tested whether pioglitazone reduced AF recurrence after electrical cardioversion (EC) by modifying systemic inflammation. In this randomized and prospective trial, patients with persistent AF and type 2 diabetes mellitus were randomized into a pioglitazone group (n=48) or a control group (n=49) before EC. Treatment was continued for 3 months or until AF recurred. Serum inflammatory markers [high sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α)] were measured at baseline and follow-up. During the 3-month follow-up, AF recurred in 22 (45.8%) patients of the pioglitazone-treated and 24 (49.0%) patients of the control group (P=0.756). However, the 3 inflammatory markers were significantly lowered with pioglitazone treatment during follow-up. Cox proportional hazards regression models showed that the predictors of recurrence included AF history (relative risk RR 1.002, 95% CI 1.003–1.061, P =0.037) and the left atrial diameter (RR 1.131, 95% CI 1.029–1.242, P = 0.010). In conclusion, while reducing some inflammatory markers, the PPARγ agonist pioglitazone did not affect the recurrence of AF after EC.