Atrial secondary tricuspid regurgitation: pathophysiology, definition, diagnosis, and treatment

Abstract

Atrial secondary tricuspid regurgitation (A-STR) is a distinct phenotype of secondary tricuspid regurgitation with predominant dilation of the right atrium and normal right and left ventricular function. Atrial secondary tricuspid regurgitation occurs most commonly in elderly women with atrial fibrillation and in heart failure with preserved ejection fraction in sinus rhythm. In A-STR, the main mechanism of leaflet malcoaptation is related to the presence of a significant dilation of the tricuspid annulus secondary to right atrial enlargement. In addition, there is an insufficient adaptive growth of tricuspid valve leaflets that become unable to cover the enlarged annular area. As opposed to the ventricular phenotype, in A-STR, the tricuspid valve leaflet tethering is typically trivial. The A-STR phenotype accounts for 10%-15% of clinically relevant tricuspid regurgitation and has better outcomes compared with the more prevalent ventricular phenotype. Recent data suggest that patients with A-STR may benefit from more aggressive rhythm control and timely valve interventions. However, little is mentioned in current guidelines on how to identify, evaluate, and manage these patients due to the lack of consistent evidence and variable definitions of this entity in recent investigations. This interdisciplinary expert opinion document focusing on A-STR is intended to help physicians understand this complex and rapidly evolving topic by reviewing its distinct pathophysiology, diagnosis, and multi-modality imaging characteristics. It first defines A-STR by proposing specific quantitative criteria for defining the atrial phenotype and for discriminating it from the ventricular phenotype, in order to facilitate standardization and consistency in research.

Keywords: Atrial fibrillation; Atrial functional tricuspid regurgitation; Secondary tricuspid regurgitation; Transcatheter interventions; Tricuspid regurgitation; Tricuspid valve.

Graphical Abstract

Characteristic aspects of atrial vs. ventricular secondary tricuspid regurgitation and the possible overlapping features that may occur between the two typical phenotypes (the check mark means ‘presence of’; the tick means ‘absence of’). Depending on its etiology, some of the listed features of ventricular secondary tricuspid regurgitation may be absent in some patients (LVEF < 50%, left-sided VHD etc). CIED, cardiac implantable electronic device; ES, end-systolic; HD, heart disease; HFpEF, heart failure with preserved ejection fraction; HVD, heart valve disease; LVEF, left ventricular ejection fraction; PH, pulmonary hypertension; RA, right atrium; RV, right ventricle; TA, tricuspid annulus; TR, tricuspid regurgitation; TV, tricuspid valve.

Figure 1

New pathophysiologic classification of tricuspid regurgitation proposed by the PCR Tricuspid Focus Group (image adapted from Hahn et al.). CIED, cardiac implantable electronic device; TR, tricuspid regurgitation

Figure 2

Anatomical relationship of the tricuspid annulus with right atrial and right ventricular myocardial fibres. (A) Atrioventricular junction, showing the insertion of the tricuspid valve leaflets; (B) Extension of right atrial myocardium at the base of the tricuspid valve leaflets, which is less present on the left side; (C) Close anatomical relationship of the tricuspid annulus with the atrial and ventricular myocardium (adapted with permission from Kato et al., Schlossbauer et al., and Muraru et al.). AW, atrial wall; CS, coronary sinus; EAT, epicardial adipose tissue; RA, right atrial; RCA, right coronary artery; RV right ventricular; TV, tricuspid valve; VW, ventricular wall

Figure 3

Suggested anatomic and functional parameters to discriminate atrial secondary tricuspid regurgitation from ventricular secondary tricuspid regurgitation from the PCR Tricuspid Focus Group and Tricuspid Valve Academic Research Consortium (TVARC). If data are discordant or incomplete (e.g. RVFWLS missing), an integrative approach based on multiple parameters is recommended. 2D, two-dimensional; 4Ch, apical four-chamber; A-STR, atrial secondary tricuspid regurgitation; CIED, cardiac implantable electronic device; EDV, end-diastolic volume; ES, end-systolic; ESV, end-systolic volume; FAC, fractional area change; LV, left ventricular; LVEF, left ventricular ejection fraction; GLS, global longitudinal strain; mPAP, mean pulmonary arterial pressure; PCWP, pulmonary capillary wedge pressure; PVR, pulmonary vascular resistance; RAV, right atrial volume; RVFWLS, right ventricular free wall longitudinal strain; RVD, right ventricular diameter; RVEF, right ventricular ejection fraction; TAPSE, tricuspid annular plane systolic excursion; TDI S, tissue Doppler systolic velocity; TR, tricuspid regurgitation; V-STR, ventricular secondary tricuspid regurgitation; WU, Woods units

Figure 4

Role of multi-modality imaging for the comprehensive characterization of atrial secondary tricuspid regurgitation patients. 3D, three-dimensional; A-STR, atrial secondary tricuspid regurgitation; CW, continuous wave; EROA, effective regurgitant orifice area; PISA, proximal isovelocity surface area; RA, right atrium; Reg Vol, regurgitant volume; RV, right ventricle; TV, tricuspid valve; VC, vena contracta. Image prepared with BioRender software

Figure 5

Proposed algorithm for managing patients with atrial secondary tricuspid regurgitation. AAD, antiarrhythmic drugs; ARNI, angiotensin receptor–neprilysin inhibitor; A-SMR, atrial secondary mitral regurgitation; A-STR, atrial secondary tricuspid regurgitation; HFpEF, heart failure with preserved ejection fraction; LA, left atrial; LV, left ventricle; MRA, mineralocorticoid receptor antagonist; PH, pulmonary hypertension; RA, right atrium; RV, right ventricle; SGLT2i, sodium–glucose co-transporter-2 inhibitor; TEER, transcatheter edge-to-edge repair; TRV, tricuspid regurgitation velocity

Figure 6

Clinical pathway and management of patients with atrial secondary tricuspid regurgitation. 2D, two-dimensional; 3D, three-dimensional; AF, atrial fibrillation; A-STR, atrial secondary tricuspid regurgitation; CMR, cardiac magnetic resonance; CT, computed tomography; HFpEF, heart failure with preserved ejection fraction; RA, right atrium; RV, right ventricle; TEE, transoesophageal echocardiography; TV, tricuspid valve; TTE, transthoracic echocardiography

Figure 7

Anatomical criteria for device selection for TTVI in patients with atrial secondary tricuspid regurgitation. A-STR, atrial secondary tricuspid regurgitation; CS, coronary sinus; RA, right atrium; RCA, right coronary artery; RV, right ventricle/ventricular; T-TEER, tricuspid transcatheter edge-to-edge repair; TTVI, transcatheter tricuspid valve intervention; TV, tricuspid valve