Timing of Intervention Recommendations for Timing of Intervention Referenced studies that support the recommendations are summarized in Online Data Supplement 32. COR LOE Recommendations In patients with severe TR (Stages C and D) undergoing left-sided valve surgery, tricuspid valve surgery is recommended.1 8 In patients with progressive TR (Stage B) undergoing left-sided valve surgery, tricuspid valve surgery can be beneficial in the context of either 1) tricuspid annular dilation (tricuspid annulus end diastolic diameter >4.0 cm) or 2) prior signs and symptoms of right-sided HF.3 10 In patients with signs and symptoms of right-sided HF and severe primary TR (Stage D), isolated tricuspid valve surgery can be beneficial to reduce symptoms and recurrent In patients with signs and symptoms of right- sided HF and severe isolated secondary TR attributable to annular dilation (in the absence of pulmonary hypertension or left-sided disease) who are poorly responsive to medical therapy (Stage D), isolated tricuspid valve surgery can be beneficial to reduce symptoms and recurrent hospitalizations.11,12,15 19 In asymptomatic patients with severe primary TR (Stage C) and progressive RV dilation or systolic dysfunction, isolated tricuspid valve surgery may be considered.12,20 In patients with signs and symptoms of right- sided HF and severe TR (Stage D) who have undergone previous left-sided valve surgery, reoperation with isolated tricuspid valve surgery may be considered in the absence of severe pulmonary hypertension or severe RV Synopsis Treatment of secondary TR is targeted at pulmonary hypertension or myocardial disease. Surgical treatment is performed for selected patients with TR at the time of surgery for left-sided valve lesions to treat severe TR (Stages C and D) and to prevent later development of severe TR in patients with progressive TR (Stage B). 