**1. Introduction**

Moderate or severe tricuspid regurgitation (TR) is a common disorder affecting over 1.6 million people in the United States and close to 70 million worldwide [1, 2]. In the vast majority of cases, the underlying mechanism is functional, due to right ventricular (RV) remodeling in patients with left-side heart disease, atrial fibrillation, primary pulmonary hypertension (PH) or RV dysfunction [3]. Although TR has been traditionally considered to be a benign valve disorder in comparison with left valve disease, it is conversely associated to a poorer prognosis. Furthermore, this finding has been consistently reported in different clinical scenarios, even in the absence of PH or right-side heart failure (HF) [4, 5]. However, most patients with significant TR only receive medical treatment and very few undergo invasive surgical approach if no concomitant coronary or left valvular disease is present [6]. Thus, surgical tricuspid valve (TV) repair or replacement in isolated TR is fairly indicated and reported periprocedural mortality can be as high as 20% [7, 8]. Recently, new percutaneous techniques have shown promising results for the treatment of TR and appear as an alternative to conventional surgery in those cases where only conservative management could be offered in the past due to high surgical risk. In this chapter we will review the different devices that are currently available and to date published evidence for these approaches.
