The progression of tricuspid regurgitation: it seems capricious, or are we just too ignorant to understand it?

This editorial refers to ‘Development of significant tricuspid regurgitation over time and prognostic indications: new insights into natural history’†, by E.A. Prihadi et al., on page 3574. The 20th century found little attention paid to tricuspid regurgitation (TR). Most TR is secondary to right ventricular (RV) pressure or volume overload and, as such, the reasoning was treat the primary cause and the TR will improve. There is of course merit to this concept. However, the 21st century brought new focus on TR for several reasons. First, the increased use of device leads that cross the tricuspid valve increased the incidence of both nuisance and more serious TR. Second, cardiac surgery performed in patients with TR due to left-side overloading valve lesions did not always improve TR following left-sided surgery. In fact, paradoxically, not only did TR fail to improve following surgery, it sometimes worsened.1 Thus, the clinician was left with a patient with well-treated left heart disease only to have them suffer from right heart failure. The problem of post-operative TR was compounded by the fact that reoperation on such patients to treat residual TR often had a very high operative risk.2 , 3 Third, we came to realize that we had very few benchmarks to guide therapy. While several parameters are recognized ‘triggers’ for left-sided intervention,4 almost none exist to guide TR therapy, leaving the clinician in a quandary about what to do and when to do it. Thus, in the surgical community, there is a broad difference of opinion regarding intraoperative management of secondary TR, ranging at one end of the spectrum where patients are aggressively treated with a dilated annulus even if TR is absent5 to, at the other end, avoiding tricuspid repair in all but the most severe cases.6 The management decision is made harder because, in some patients, TR improves following left-sided surgery, only to worsen later in time.7–9 The only area of agreement is that tricuspid repair or replacement at the time of left-sided surgery reduces TR or prevents its worsening post-operatively.10 , 11 There is some evidence that TR treatment during left-sided surgery reduces post-operative heart failure,12 , 13 but there is little proof that TR treatment improves long-term survival, albeit there have been no rigorous prospective survival trials to adequately examine the hypothesis.