Isolated severe tricuspid regurgitation: an unrecognised and undertreated problem of the forgotten valve

Until recently, there has been little attention paid to the treatment of tricuspid regurgitation (TR) aside from small series of patients with congenital disease or infective endocarditis. This reflects both the relative rarity of ‘primary TR’, as well as the perception that most TR was felt to be ‘secondary’ to pulmonary hypertension or a cardiomyopathic process, in which case the treatment was directed towards the underlying cause. However, there is now recognition of an increasing number of patients who present with ‘isolated’ TR. ‘Isolated TR’ is defined as the absence of primary tricuspid leaflet pathology, the absence of pulmonary hypertension and normal or near-normal left ventricular (LV) systolic function: in such cases, it is the TR itself that results in the signs and symptoms of right heart failure (HF). Such isolated TR is commonly associated with (1) chronic atrial fibrillation, (2) prior left heart surgery or (3) pacemaker device leads. Even with increased recognition of isolated TR, there is a reluctance to operate, in part due to a high reported operative mortality. Notably, despite increasing numbers of operations across the country, a high mortality rate of 10%–15% persisted in several studies.1 2 Therefore, patients are often conservatively managed or referred only at a late stage for surgery with advanced right HF and end-organ damage; and this approach has not unsurprisingly been associated with poor outcomes. In a recent cohort study from the national readmission database (2016–2017), >40% of patients who underwent isolated tricuspid valve (TV) surgery were referred late for surgery, with a fourfold higher operative mortality compared with those who had a timely referral.3 In this setting, Park et al 4 have contributed to an important observational study of 238 patients undergoing isolated TV surgery over nearly two decades at a large medical centre in South Korea. …