Tricuspid Regurgitation: Predicting the Need for Interventio
Interest in tricuspid valve (TV) pathology has rapidly expanded in response to studies showing poor clinical outcomes in patients with functional tricuspid regurgitation (TR) and the limited indications and options for treatment, resulting in significant undertreatment of the disease. Primary TR due to primary valve lesions is currently uncommon, with causes including rheumatic heart disease, myxomatous valve disease, Ebstein’s anomaly, infective endocarditis, carcinoid or infiltrative valvulopathy, and iatrogenic trauma (pacemaker or implantable cardioverter-defibrillator leads or right ventricular [RV] biopsy).

The etiology of more than 90% of TR is functional or secondary in the setting of tricuspid annular (TA) dilatation, with or without tricuspid leaflet tethering. There are multiple etiologies of secondary TR. The least common is isolated functional TR (FTR), in which mid-RV shape and function remain normal and isolated annular dilatation in the setting of aging or chronic atrial fibrillation result in right atrial (RA) enlargement and TA remodeling. Another uncommon etiology of secondary TR is primary RV disease, including isolated RV infarction.

The most common etiology of secondary TR is left-sided heart disease and pulmonary hypertension (either pre-capillary or post-capillary). Prihadi et al. showed that >60% of patients with significant TR on echocardiography had left heart myocardial disease, native left-sided valvular disease, or prior left-sided valve surgery. Irrespective of the specific initial etiology, TR is a progressive disease in the setting of RV and RA remodeling.

Interest in FTR has expanded rapidly in the setting of poor clinical outcomes associated with the disease and the limited indications and options for treatment. Currently, severe FTR should be addressed at the time of surgery for left-sided valve disease, but ongoing trials will assess the utility of earlier intervention. Given the high surgical risk for isolated TV surgery, novel transcatheter techniques (both repair and replacement) are currently being investigated. Future trials will clarify the role of medical therapy and interventions in patients with TR disease.