Is it real that no idiopathic tricuspid regurgitation anymore after atrial tricuspid regurgitation regarded as a distinct entity?

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background We have recently found that idiopathic tricuspid regurgitation (TR) had unique characteristics after a systemic approach to strictly define it. Atrial TR has been proposed that TR caused by right atrial dilatation related to the atrial fibrillation and without other causes of TR. Some researchers suggested idiopathic TR was no longer existed. Methods We retrospectively recruit 978 subjects with significant (moderate and severe) TR during a period of 9 months. We carefully evaluated their echocardiography images and divided these subjects into different type of TR according to a step-by-step systemic approach which we have developed. The characteristics of these TR were compared. Results After a step-by-step diagnostic approach, we found that there were 105 subjects with primary TR (10.7%), 76 (7.8%) pacemaker or other intracardiac instrumentation related, 388 (39.7%) left heart disease related, 32 (3.3%) congenital heart disease related, 160 (16.3%) pulmonary hypertension related, 7 (0.7%) right ventricular myopathy, and 210 (21.5%) idiopathic TR. Among idiopathic TR, 81 (38.6%) men, mean age 74.4 ± 14.0 years, 35 (16.7%) severe TR, and 82 (39%) atrial fibrillation. Compared to the idiopathic TR in sinus rhythm, subjects with atrial fibrillation had older age (78.1 ± 10.4 vs. 72.0 ± 13.9 years, p = 0.001), more severe TR (32 vs. 7 %, p <0.001), higher pulmonary artery pressure (43.5 ± 9.8 vs. 38.9 ± 7.9 mmHg, p = 0.001), less fractional area fraction of right ventricle (44.9 ± 13.3 vs. 51.1 ± 10.8 %, p = 0.001), larger tricuspid annulus (3.4 ± 0.7 vs. 2.8 ± 0.6 cm, p <0.001), and large right atrial area (23.2 ± 7.6 vs. 13.6 ± 4.5 cm2, p <0.001). Conclusion There were only 39% atrial TR among idiopathic TR in our study. Many significant TR subjects without other causes were still in sinus rhythm with smaller annulus and right atrial size. Even atrial TR do a distinct entity, there are still have TR subjects without any obvious causes (idiopathic TR).