The Tricuspid Valve: A Review of Pathology, Imaging, and Current Treatment Options

Authors, Journal, Affiliations, Type, DOI

• Laura J. Davidson, Gilbert H.L. Tang, Edwin C. Ho, Marat Fudim, Tiberio Frisoli, Anton Camaj, Margaret T. Bowers, Sofia Carolina Masri, Pavan Atluri, Joanna Chikwe, Peter J. Mason, Jason C. Kovacic, George D. Dangas (Chair)
• Circulation, 2024;149:e1223–e1238
• Affiliations: Multiple US and international centres (Northwestern, Mount Sinai, Duke, Henry Ford, Penn, Cedars-Sinai, Wisconsin, Victor Chang Cardiac Research Institute)
• Type: AHA Scientific Statement (on behalf of the Interventional Committee of the Council on Clinical Cardiology + 3 other councils)
• DOI: 10.1161/CIR.0000000000001232 | Published May 28, 2024

Overview

This AHA Scientific Statement provides a comprehensive review of tricuspid valve (TV) disease, historically underappreciated despite 0.55% population prevalence (4% in ≥75 years) and 10.2% 15-year survival for moderate/severe TR. It covers complex TV anatomy (Type I–IV leaflet nomenclature), TR pathophysiology (primary vs secondary atrial vs ventricular), multimodality imaging including ICE, the expanded 5-grade TR severity scale, and the full therapeutic spectrum from medical therapy through surgery to transcatheter repair and replacement. The transcatheter section includes the first published RCT (TRILUMINATE Pivotal: win ratio 1.48, QoL improvement, no mortality/HF hospitalisation benefit) and EVOQUE EFS/TRISCEND II data leading to FDA approval of both TriClip (TEER) and EVOQUE (replacement). The paper emphasises anatomy-guided lifetime management with no single device suitable for all patients.

Keywords

Tricuspid valve, tricuspid regurgitation, heart failure, heart valve prosthesis implantation, pulmonary hypertension, transcatheter edge-to-edge repair

Key Takeaways

Epidemiology

• Moderate or severe TR: age-sex adjusted prevalence 0.55% in US; 4% in ≥75 years
• Observed survival with moderate-severe TR: 10.2% at 15 years; highest mortality with functional TR + left-sided heart disease
• Isolated TR: yearly mortality 12.1%
• TR after CIED implantation: 7–45% prevalence

TV Anatomy

• Classic anatomy: 3 leaflets — anterior (largest, most mobile), posterior (often multi-scalloped), septal (smallest, arises from IVS with multiple chordal attachments)
• New nomenclature (Type I–IV): Type I = 3 leaflets; Type II = 2; Type III = 4 (IIIA: 2 anterior, IIIB: 2 posterior, IIIC: 2 septal); Type IV = >4 leaflets. ~39% of cases have ~4 functional leaflets
• Annulus: nonplanar, elliptical; anteroseptal portion is most atrial (highest); posteroseptal most ventricular (lowest); dilation occurs preferentially anterolaterally (RV free wall direction)
• Subvalvular apparatus: 2–3 papillary muscles; anterior papillary muscle is largest (supports anterior + posterior leaflets); septal papillary muscle variable
• Adjacent structures: RCA (in AV groove), AV node + His bundle (adjacent to septal leaflet/anteroseptal commissure), coronary sinus (posteroseptal RA), aortic root (noncoronary sinus, near anteroseptal commissure), IVC (variable relationship to TA)

Pathophysiology of TR

Primary TR

• Pure RV volume overload → annular dilation
• Structural causes: leaflet perforation/restriction, commissural fusion, chordal entanglement/rupture

Secondary Ventricular TR (most prevalent)

• Most common mechanism: PH → maladaptive RV remodeling (anterolateral wall, midventricular) → papillary muscle displacement (anterior PM moves caudally) → leaflet tethering
• TR-generating-TR vicious cycle: TR → RV dilation → RV systolic dysfunction → ↑RV diastolic pressure → IVS shift toward LV → LV compression → ↑PH → worse tethering
• Other causes: RV infarct, chronic RV pacing, left-sided VHD, LV dysfunction

Secondary Atrial TR

• AF or HFpEF → RA/annular dilation with relatively spared RV and normal leaflets
• Advanced stages may overlap atrial and ventricular mechanisms — blurring of categories

CIED-Related TR

• 7–45% incidence post-CIED; often coexists with underlying atrial/ventricular TR
• Mechanisms: lead impingement, entanglement, adherence, leaflet perforation, complications of lead extraction

Imaging

Transthoracic Echocardiography

• Multiple views required: parasternal RV inflow, parasternal short-axis, apical 4-chamber (with anterior and posterior focus), subcostal
• TR easily underestimated if full large TA not captured; probe angulation critical
• 3D TTE and biplane echocardiography helpful for annular anatomy, leaflet morphology, and mechanism
• Special challenge: CIED-induced TR (3D echo assists lead visualisation)

Transesophageal Echocardiography

• Primary modality for intraprocedural guidance
• Transgastric short-axis view: visualises all leaflets simultaneously; defines mechanism and regurgitation site
• 3D TEE with MPR: en face view from RA or RV perspective; defines leaflet anatomy and TA size
• Limitations: TV distance from probe, variable anatomy, device shadowing; TEE window inadequate in some patients

Intracardiac Echocardiography (ICE)

• Alternative when TEE window suboptimal
• ICE catheter positioned in RA from femoral vein
• 2D ICE: higher imaging frequency and frame rate than TEE; essential in ~70% of TEER cases where used
• 3D MPR ICE: lower temporal resolution; decreases further with color Doppler
• 4D ICE used for annuloplasty procedures — improved lateral annulus visualisation vs TEE
• Added cost and operator learning curve are disadvantages

Computed Tomography

• High spatial resolution for TA measurements, RCA proximity, complex subvalvular anatomy (moderator band, trabeculation) for TTVR planning
• TR quantification feasible: LV vs RV stroke volume difference; anatomic regurgitant orifice area correlates with 3D TEE VCA (tends to be higher than EROA)
• Essential for delivery catheter planning: femoral/iliac/IVC diameter, tortuosity, IVC-to-TA relationship and trajectory for device delivery

Cardiac Magnetic Resonance

• Accurate RV volumes, RVEF, TR quantification (phase-contrast flow)
• Useful when echo underestimates TR or RV dysfunction
• Baseline RVEF particularly relevant pre-TTVR (risk of acute afterload mismatch post-TR elimination)

Grading TR Severity (5-Grade Scale, 2017)

• Dense, early-peaking, triangular CW Doppler envelope: indicative of severe TR (rapid RV-RA pressure equalisation)
• Hepatic vein flow reversal: moderate or severe TR
• Imaging should be in euvolaemic state for accurate grading

RV Function Assessment

• TAPSE, tissue-Doppler S', fractional area change, RV free-wall longitudinal strain (speckle tracking), 3D RVEF
• RV-PA coupling (TAPSE/sPAP ratio): high baseline TAPSE/sPAP independently associated with lower all-cause mortality post-TV intervention
• PA pressure may be underestimated in severe TR + poor RV function (V-wave cutoff sign on CW Doppler)

Medical Therapy

• Primary TR: Diuretics Class 2a to relieve right-sided congestion; treat primary cause
• Secondary TR: GDMT for LV dysfunction (Class I HFrEF drugs: RAAS/ARNI, BB, MRA, SGLT2i); HFpEF: diuretics Class I, SGLT2i Class 2a, ARNI/MRA/ARB Class 2b
• Vasodilators for PAH; rhythm control for AF (variable effect on TR — not consistent evidence)
• Invasive haemodynamic monitoring (PA catheter) to guide therapy in severe TR
• No medical (nonprocedural) therapy can directly reverse primary or secondary TR — only improves TR through volume status change and atrial/ventricular remodeling
• Post-intervention: continue diuretics (dose may decrease); inotropic support may be needed post-TV surgery

Surgery

Indications (ACC/AHA 2020)

• Class I: TV surgery at time of left-sided valve surgery for severe TR
• Class IIa: Symptomatic severe TR without severe RV dysfunction or PH; isolated secondary TR with annular dilation poorly responsive to medical therapy
• Class IIb: Asymptomatic severe primary TR with progressive RV dilation/dysfunction

Options: Repair vs Replacement

• Repair (preferred): Ring annuloplasty is gold standard; DeVega suture-based largely abandoned due to durability concerns; undersized ring effective for dilated annulus or when CIED leads do not affect leaflet mobility
• Replacement: Reserved for unrepairable valves (carcinoid, congenital, endocarditis with extensive damage); mechanical vs bioprosthetic — similar failure/mortality/reoperation at 5 years; bioprostheses durability approaching 15 years; mechanical may show earlier adverse events

Outcomes

• Overall in-hospital mortality: 8–10% (driven by comorbidities: RV, renal, liver dysfunction)
• Without major risk factors: 1.7% national mortality
• Isolated TV surgery: ~20% of all TV surgeries (~5,000 over 10 years in US)
• Volume-outcome relationship suggested (single-centre data better than national data)
• Patients undergoing surgery are significantly younger than transcatheter therapy patients

CIED-Related TR Surgical Options

• Medical therapy, lead extraction ± repositioning, or surgical TV repair
• Transcatheter TEER also feasible with similar outcomes vs non-CIED TR

Transcatheter Repair

Transcatheter Edge-to-Edge Repair (TEER)

• TriClip G4 (Abbott): 4 clip sizes; steerable guide catheter with 2 knobs; analogous to MitraClip G4
  • TRILUMINATE Global EFS (n=85): TR ≤moderate in 71% at 1 year; RV and RA reverse remodeling
  • TRILUMINATE Pivotal (RCT): TriClip TEER vs optimal GDMT in intermediate/high surgical risk
    • Win ratio 1.48 (95% CI 1.06–2.13; p=0.02): favors TEER
    • No significant difference in 1-year mortality or HF hospitalizations (annualised HF hospitalization rate: 0.21 vs 0.17 events/patient-year)
    • KCCQ-12: +12 points (device) vs +0.6 points (GDMT); p<0.001
    • 87% had ≤moderate TR at 30-day follow-up
    • Greater QoL benefit if residual TR ≤moderate or >1 grade TR reduction
  • FDA approved for symptomatic severe TR to reduce TR severity and improve QoL
• PASCAL Precision (Edwards): Central spacer design; arms clasp leaflets; mitral + tricuspid use
  • 1-year EFS (n=30): 86% achieved TR ≤moderate
  • CLASP TR US EFS (n=34): 85% had ≥1 grade TR reduction; 52% had TR ≤moderate at 30 days
  • CLASP TR Pivotal RCT (vs optimal GDMT): ongoing; 2-year endpoint

Transcatheter Annuloplasty

• Cardioband (Edwards Lifesciences): First CE-mark approved (2018) transcatheter TV therapy
  • Anchors implanted in annulus via femoral vein; implant cinched to reduce annular size
  • EFS (n=37): 83% procedural success; 73% had ≥2 grade TR reduction at 1 year; 73% TR ≤moderate
  • NYHA class I/II doubled baseline to 1 year; KCCQ improvement
  • 4D ICE enhanced imaging especially for lateral annulus

TV-in-Valve and Valve-in-Ring

• Off-label alternative to redo surgery in prior surgical TV annuloplasty or replacement
• Balloon-expandable TAVR devices used; TV-in-valve straightforward with favourable midterm outcomes
• TV-in-ring: more challenging; higher paravalvular leak and residual TR
• CIED leads create additional technical challenges (lead damage/dislodgement risk)

Transcatheter Replacement

Orthotopic (Native TA Position)

• EVOQUE (Edwards Lifesciences): Self-expanding bovine pericardial valve; nitinol frame; fabric skirt; 9 RV anchors
  • TRISCEND EFS (n=56 high-surgical-risk): 98.2% technical success; 96.4% procedural success
  • 98.1% mild or less TR at 30 days; 11% pacemaker implantation; 3.6% 30-day mortality
  • Significant improvements in NYHA class, 6MWD, KCCQ at 30 days
  • FDA approved based on TRISCEND II 6-month results (symptomatic severe TR despite optimal medical therapy)
  • Also received CE mark
• INTREPID (Medtronic): Bovine pericardial valve; nitinol dual stent frame; no leaflet capture needed; EFS underway (US)
• Other systems in development: LuX-Valve Plus, Cardiovalve, TriSol, Topaz

Heterotopic (Outside Native TA)

• Targets venous congestion symptoms without direct TA implantation
• TricValve: 2 independent self-expanding bovine pericardial valves in IVC and SVC via transfemoral approach
• TRICENTO: Custom bicaval covered stent (IVC → RA → SVC); bicuspid pericardial valve oriented toward native TA; EFS (n=21 high-risk): 100% procedural success, no in-hospital mortality, improved NYHA in majority at 61-day follow-up

TriValve Registry

• First and only multicenter global registry of transcatheter TV interventions (since 2017)
• Substudies: TEER, medical vs transcatheter management, CIED-induced TR, combined mitral+tricuspid, massive/torrential TR, RV dysfunction + PH, prior left-sided valve surgery, sex differences
• Key finding: high baseline TAPSE/sPAP ratio independently predicts lower all-cause mortality post-intervention

Therapy Selection and Lifetime Management

• No guidelines yet to determine repair vs replacement for individual patients
• TEER: limited by large coaptation gaps (AF/RV failure-driven annular dilation); imaging quality requirements; incomplete TR elimination
• Transcatheter annuloplasty: preserves future options (can proceed to TEER or TTVR); long procedural time
• TTVR: eliminates TR in most; CT screening mandatory; pacemaker risk; anticoagulation; device thrombosis risk
• Sequence matters: annuloplasty first may preserve TEER/TTVR options later; some TEER devices may preclude future devices
• Frailty/age/goals of care: elderly frail patients → QoL focus; younger patients → durability and lifetime sequencing
• Severe PH: concern about acute afterload mismatch with sudden complete TR elimination → gradual reduction preferred
• Liver function assessment mandatory (TR-related hepatic congestion vs intrinsic liver disease affects long-term outcomes)
• Volume optimisation (medical or "prehab" admission for IV diuresis) before imaging/procedure for accurate grading

Limitations of the Document

• Most transcatheter data from single-arm EFS rather than RCTs; only TRILUMINATE Pivotal is an RCT
• No mortality benefit demonstrated in any transcatheter TV RCT to date
• Long-term device durability data lacking for all transcatheter devices
• TRILUMINATE Pivotal: QoL-driven win ratio — HF hospitalisation and mortality not significantly improved
• CIED-associated TR management data largely observational
• Imaging guidance for patient selection remains heavily centre-dependent; standardisation limited

Key Concepts Mentioned

• concepts/Tricuspid-Regurgitation — primary subject; anatomy, grading, therapy
• concepts/RV-PA-Coupling — TAPSE/sPAP as prognostic marker in TR
• concepts/Valvular-Heart-Disease — TR as part of VHD spectrum
• concepts/Secondary-Mitral-Regurgitation — analogous secondary regurgitant mechanism; TEER technology cross-use
• concepts/Structural-Valve-Deterioration — future concern for transcatheter TV devices

Key Entities Mentioned

• entities/Pulmonary-Hypertension — primary driver of ventricular secondary TR
• entities/Heart-Failure — underlying substrate for secondary TR; GDMT cornerstone
• entities/Atrial-Fibrillation — driver of atrial secondary TR; rhythm control variable benefit on TR

Wiki Pages Updated

• wiki/sources/TV-Mx-AHA-2024.md — created (this file)
• wiki/sourceindex.md — added entry
• wiki/wikiindex.md — updated Tricuspid-Regurgitation date
• wiki/concepts/Tricuspid-Regurgitation.md — added AHA 2024 anatomy detail, 5-grade grading table, device-specific trial data (TRILUMINATE/EVOQUE/Cardioband), heterotopic replacement, lifetime management framework