Atrial fibrillation (AF) provides extremel rapid excitation frequency in both atria, and induces several pathophysiological mechanisms by influencing each other to promote AF. This auto-enhancing feature is often described by the well-known concept “AF begets AF”. The cure of AF by creating pulmonary vein (PV) isolation may be able to reverse the spiral and be able to achieve reverse remodeling. Because of the initial focus on PV in the pathogenesis of AF, the effects of reverse remodeling after catheter ablation (CA) have been investigated on improvement of the left-sided cardiac system. On the other hand, tricuspid regurgitation (TR), the most neglected of all valvular diseases, is increasingly recognized as an important prognostic condition in heart failure patients. Previous reports, which tested the role of CA for AF patients with TR, have demonstrated that maintenance of SR provides reverse remodeling of the right-sided cardiac system, but have yet to prove whether this leads to improvement in patient prognosis. What is new and noteworthy about the report by Ukita et al. in this issue is that they found that TR improvement itself improves major event-free survival rate (incidence of heart failure hospitalization and all-cause mortality). However, several issues remain unresolved in their report. They observed a low AF recurrence rate in the TR-improved group, but did not address the possibility that AF suppression itself contributed to improve event-free survival rate. Further investigation is required to clarify whether TR improvement or maintenance of SR is the greater contributor to improved prognosis in AF.