Tricuspid Regurgitation, the Once-Forgotten Valve: Current Management Options and Remaining Gaps After the 2025 European Society of Cardiology Guidelines Update

Historically considered a “neglected” valvular disease, moderate-to-severe tricuspid regurgitation (TR) is now recognized as an important contributor to morbidity, mortality, and right-sided heart failure (HF). Natural history studies show that significant TR is frequently associated with left-sided valve disease, particularly mitral valve disease, and independently predicts poor outcomes as severity increases. The 2025 European Society of Cardiology (ESC)/European Association for Cardio-Thoracic Surgery (EACTS) Guidelines for the Management of Valvular Heart Disease place unprecedented emphasis on TR, elevating this condition from a secondary afterthought to a central element of comprehensive valvular therapy. This reflects an evolution of evidence over the past decade, underscored by increased diagnostic sensitivity through multimodal imaging and the development of novel therapeutic options. However, gaps in the existing evidence persist, and addressing these uncertainties will support future research. This paper provides a comprehensive review of the evidence on TR, incorporates updates from the latest European guidelines, focuses on the most relevant and controversial aspects of patient selection, and identifies key areas where knowledge is insufficient. Furthermore, this review revisits the historical foundations of tricuspid valve research, highlighting how several anatomical concepts fundamental to contemporary interventions were already described as early as the 17th century, underscoring the long-standing scientific interest in this once “forgotten” valve.