The optimal management of patients with functional tricuspid regurgitation (TR) at the time of left-sided heart-valve surgery continues to cause controversy. It is well recognised that patients with severe functional TR should have concomitant tricuspid-valve repair, but the management of mild or moderate TR at the time of left-sided heart-valve surgery continues to be debated.1

In this issue of the journal, Song et al (see article on page 931) address the very important question of whether mild TR should be surgically addressed during left-sided heart-valve surgery.2 In a retrospective study of 638 patients who underwent left-sided heart-valve surgery without tricuspid valve surgery, 548 patients had none or trace TR (grade 0–1/4), and 90 patients had mild TR (grade 2/4). At a mean follow-up of 64 months, moderate or severe TR developed in 7.3% in those who had none or trace TR, and in 20% in those who had mild TR. Compared with patients who did not develop significant late TR, patients who developed significant late TR had a higher late mortality (16.3% vs 4.9%, p = 0.004) and a lower event-free survival (76% vs 91%, p<0.001).

Limitations to this study include:

1. It is a retrospective study and measurements of TR grade and tricuspid annulus size were done retrospectively. It is well recognised that retrospective assessment of such parameters is not as accurate as real-time assessment, as adequate imaging views may not have been obtained. Moreover, a single preoperative echo measurement of TR severity done at rest may not reflect the true severity of TR, as this is dependent on right ventricular (RV) preload, afterload and contractility.

2. The aetiology of the left-sided heart-valve lesion included a high proportion of patients with rheumatic valve disease (45%). Although the authors report that there was no rheumatic involvement of the tricuspid valve by …