It has been reported to plays an essential role in TGF-β1-elicited fibrogenesis underlying atrial fibrillation in humans, and in the cardiac remodeling induced by TGF-β1 and angiotensin II.22 Therefore, the direct effect of OCS on cardiac fibroblasts might also have contributed to a part of the ameliorating effect of OCS on the RV remodeling and function. Here, TGFB1 is linked to atrial fibrillation.