New etiological classification of tricuspid regurgitation

Earlier, tricuspid regurgitation was classified into primary and secondary TR. Primary TR was TR in which abnormalities of tricuspid valve caused the regurgitation. In secondary TR, tricuspid valve leaflets were normal, but structural changes in the tricuspid annulus or right ventricle resulted in poor leaflet coaptation and regurgitation. A new comprehensive classification has been introduced by the Tricuspid Valve Academic Research Consortium [1]. There are three categories in this classification with a few subclassifications as well. Secondary TR is divided into atrial secondary tricuspid regurgitation and ventricular secondary tricuspid regurgitation, just as in the case of mitral regurgitation. TR associated with cardiac implantable electronic device (CIED) leads has been divided into type A where the lead is causing TR and type B in which CIED lead is just an incidental finding.

Primary TR contributes to only 5-10% and could be degenerative due to prolapse or flail leaflet, congenital as in apical displacement of Ebstein’s anomaly, or acquired as in tumors, trauma, carcinoid, rheumatic heart disease or radiation. Secondary TR is the commonest, contributing to 80%. Ventricular secondary TR could be due to heart failure, either HFpEF or HFrEF, left sided valvular lesions causing post capillary pulmonary hypertension, pulmonary cause for precapillary pulmonary hypertension, or due to a right ventricular cause with RV dilatation or dysfunction as in RV infarct or dysplasia. Atrial secondary TR is due to right atrial or tricuspid annular dilatation,which could be related to age, atrial fibrillation or HFpEF.

CIED related TR contributes to around 10-15% and in the causative variety, leaflet impingement, perforation, valvular or subvalvular adhesions or restriction. In the incidental variety, the CIED lead is present without interfering the tricuspid valve apparatus. Pathology will be that of the primary disease process. So it will be one of the previous classes.

Reference

1. Hahn RT, Lawlor MK, Davidson CJ, Badhwar V, Sannino A, Spitzer E, Lurz P, Lindman BR, Topilsky Y, Baron SJ, Chadderdon S, Khalique OK, Tang GHL, Taramasso M, Grayburn PA, Badano L, Leipsic J, Lindenfeld J, Windecker S, Vemulapalli S, Redfors B, Alu MC, Cohen DJ, Rodés-Cabau J, Ailawadi G, Mack M, Ben-Yehuda O, Leon MB, Hausleiter J; TVARC Steering Committee. Tricuspid Valve Academic Research Consortium Definitions for Tricuspid Regurgitation and Trial Endpoints. J Am Coll Cardiol. 2023 Oct 24;82(17):1711-1735. doi: 10.1016/j.jacc.2023.08.008. Epub 2023 Oct 4. PMID: 37804294.