Functional TR is a progressive disease and if left untreated, will progress with worse survival [5]. In a recent study by Song et al., involving 638 patients who underwent left sided heart valve surgery without tricuspid valve surgery, moderate or severe TR was present at 5 years in 7.3 % of those who had none or trace TR at their initial surgery, and in 20 % of those who had mild TR [6]. Survival was significantly worse in those who developed late TR. Similarly, Dreyfus et al. reported that significant late TR developed in 34 % of patients who underwent mitral valve repair without tricuspid valve surgery and this was associated with worse NYHA functional class [7]. Matsunaga and Duran meanwhile reported an incidence of moderate or severe TR in 75 % of patients 3 years after mitral valve repair for functional ischaemic mitral regurgitation [8]. Calafiore et al. reported that TR progressed in 40 % of patients following mitral valve surgery without tricuspid valve surgery and this was associated with worse survival and functional class [9]. Yilmaz et al. meanwhile reported that mean TR grade increased significantly from a mean of 1.84–2.11 (p = 0.03) 5 years after isolated mitral valve surgery without concomitant tricuspid valve surgery, and 29.4 % of patients had moderate or more TR at 5 years compared to 16.5 % pre-operatively [10].

Important factors which may influence the progression of TR include the presence of annular dilatation, leaflet tethering and atrial fibrillation [11, 12]. TR is likely to progress if tricuspid annular dilatation or leaflet tethering are present and not addressed at the time of left sided heart valve surgery [11]. Conversely, TR is unlikely to progress in patients with mild TR and no significant annular dilatation, leaflet tethering or atrial fibrillation [11].