We read the work by Shimony et al published in a recent issue of The American Journal of Cardiology . Their work is commendable and describes a novel risk predictor for postoperative atrial fibrillation (POAF), namely, right ventricular myocardial performance index (RV-MPI). The investigators have postulated the role of inflammatory markers in the causation of right ventricular dysfunction and POAF. There has been significant evidence from previous studies to suggest the role of pericardial adiposity in arrhythmogenesis. Recently, it has been shown that increased pericardial fat volume is also strongly associated with POAF after coronary artery bypass grafting.

It is hypothesized that epicardial fat modulates the adjacent myocardial tissue by exerting a local paracrine effect with increased expression of numerous inflammatory markers such as interleukin 6. It has also been questioned that proinflammatory nature of epicardial fat may increase the chances of heart failure because of its anatomic proximity to the myocardium. It thus remains an intriguing question for future studies to see if the epicardial fat tissue burden and pericardial fat volume have an independent correlation to RV-MPI. The available evidence from these studies however reinforces the consideration for prophylactic use of anti-inflammatory therapies such as statins and colchicine. Although anti-inflammatory therapies have been shown to reduce POAF in controlled investigations (like colchicine in COlchicine for the Prevention of the Post-pericardiotomy Syndrome [COPPS] substudy), to the best of our knowledge, a direct comparison of the serum inflammatory markers with anti-inflammatory therapies and RV-MPI is lacking.

Thus, a direct comparison of the serum inflammatory markers with the epicardial fat burden, RV-MPI, and anti-inflammatory therapies is warranted in future prospective investigations, which would provide a better insight into the etiopathogenesis of POAF after coronary artery bypass grafting. It would also be important to account for the preoperative incidence of interatrial blocks in both the groups, as it can independently affect the conduction and lead to POAF.