#valvular-heart-disease #tricuspid-regurgitation #transcatheter-interventions

Tricuspid Regurgitation

Definition

Tricuspid regurgitation (TR) is retrograde systolic flow from the RV into the RA due to structural abnormality of the tricuspid valve (primary TR) or due to functional changes from RV/RA dilatation and leaflet tethering (secondary TR). Significant TR (≥moderate) affects 0.55% of the population (4% in those ≥75 years) and is independently associated with death and HF; 15-year observed survival is 10.2%, and isolated TR carries 12.1% annual mortality. sources/TV-Mx-AHA-2024 high

Key Concepts

TV Anatomy

Classic anatomy: 3 leaflets — anterior (largest, most mobile), posterior (often multi-scalloped), septal (smallest, arises from IVS with multiple chordal attachments)
Leaflet nomenclature (Type I–IV): Type I = 3 leaflets; Type II = 2; Type IIIA/B/C = 4; Type IV = >4 leaflets. ~39% of cases have ~4 functional leaflets predominantly comprising 2 posterior leaflets sources/TV-Mx-AHA-2024 high
Annulus: nonplanar, elliptical; posteroseptal = most ventricular; anteroseptal = most atrial; annular dilation occurs preferentially anterolaterally (RV free wall direction, away from fibrous skeleton support from the septum)
Adjacent critical structures: RCA (AV groove), AV node + His bundle (adjacent to septal leaflet/anteroseptal commissure), coronary sinus (posteroseptal RA), aortic root (non-coronary sinus near anteroseptal commissure) sources/TV-Mx-AHA-2024 high

Aetiology

Primary TR (8–10%): Infective endocarditis, rheumatic disease, carcinoid, congenital (Ebstein's), trauma, iatrogenic (endomyocardial biopsy), CIED-related (lead-induced valve damage)
Secondary TR (>90%):
- Atrial secondary TR: AF-driven; RA and annular dilatation with preserved RV function and pulmonary pressures; no significant leaflet tethering
- Ventricular secondary TR: LV/RV disease or post-capillary PH causing annular dilatation + leaflet tethering; worse prognosis
Advanced stages may blur the atrial vs ventricular distinction — early characterisation is critical sources/vhd-esc-2025 very high

Evaluation

TR Severity Grading (5-Grade Scale, ASE/AHA 2017)

Grade	VC width (cm)	EROA by PISA (cm²)	3D VCA/quantitative EROA (cm²)
Mild	<0.3	<0.2	—
Moderate	0.3–0.69	0.2–0.39	—
Severe	0.7–1.3	0.4–0.59	75–94
Massive	1.4–2.0	0.6–0.79	95–114
Torrential	≥2.1	≥0.8	≥115

VC measured as average of 2 orthogonal views; 3D VCA preferred for complex jets
Dense early-peaking triangular CW Doppler envelope = rapid RV-RA pressure equalisation → severe TR
Hepatic vein flow reversal = moderate or severe TR
PA pressures may be underestimated in severe TR due to V-wave cutoff sign on CW Doppler
Assess when euvolaemic; repeat imaging after volume optimisation if overloaded at baseline sources/TV-Mx-AHA-2024 high

Multimodality Imaging

TTE: Multiple views (parasternal RV inflow, short-axis, apical 4-chamber anterior + posterior focus); TR easily underestimated if full large TA not imaged; 3D TTE and biplane improve annular anatomy and leaflet characterisation sources/TV-Mx-AHA-2024 high
TEE: Primary modality for intraprocedural guidance; transgastric short-axis en face view visualises all leaflets simultaneously; 3D TEE with MPR for en face RA/RV perspective; limited by probe-to-TV distance, variable anatomy, device shadowing sources/TV-Mx-AHA-2024 high
ICE: Alternative to TEE when window suboptimal; 2D ICE (higher frame rate) essential in ~70% TEER cases; 4D ICE for annuloplasty (superior lateral annulus visualisation); added cost and learning curve sources/TV-Mx-AHA-2024 high
CT: Annular measurements, RCA proximity, subvalvular anatomy for TTVR planning; TR quantification (RV-LV stroke volume difference); delivery catheter planning (femoral/iliac/IVC diameter, IVC-TA trajectory) sources/TV-Mx-AHA-2024 high
CMR: Accurate RV volumes/RVEF and TR quantification (phase-contrast); baseline RVEF important pre-TTVR (afterload mismatch risk) sources/TV-Mx-AHA-2024 high
Integrative echo grading based on qualitative + quantitative parameters; assessment in euvolaemic state
RHC mandatory before any intervention: RA pressure, end-diastolic RVDP, mean PAP, PAWP, PVR — essential to exclude masked pre-capillary PH (poor outcome predictor)
TRI-SCORE and STS isolated TV risk calculator for peri-operative risk stratification sources/vhd-esc-2025 very high

RV Function Assessment

TAPSE, TDI S', FAC, RV free-wall longitudinal strain (speckle tracking), 3D RVEF
RV-PA coupling (TAPSE/sPAP): High baseline ratio independently associated with lower all-cause mortality post-TV intervention; use caution as PA pressures may be underestimated in severe TR sources/TV-Mx-AHA-2024 high

Medical Therapy

Treat underlying cause: GDMT for HF, pulmonary vasodilators for PH, rhythm control for AF
Primary TR: Diuretics Class 2a; treat primary cause
Secondary TR (HFrEF): RAAS/ARNI + BB + MRA + SGLT2i Class I — reduces secondary TR through structural reverse remodeling
Secondary TR (HFpEF): Diuretics Class I; SGLT2i Class 2a; ARNI/MRA/ARB Class 2b
Rhythm control for AF: variable effect on TR depending on underlying cause, atrial dilation, and other conditions — evidence not consistent
No medical therapy can directly reverse TR — only improves it indirectly through volume and structural remodeling sources/TV-Mx-AHA-2024 high
Diuretics in stepwise fashion (loop diuretics → aldosterone antagonists → SGLT2i)
Medical therapy has very limited effect on TR severity — should not delay expert centre evaluation when TR is significant sources/vhd-esc-2025 very high

Surgical Indications and Outcomes

Outcomes Data (AHA 2024)

Overall in-hospital mortality: 8–10% (comorbidities: RV/renal/liver dysfunction)
Without major risk factors: 1.7% national mortality; single-centre results better (volume-outcome relationship)
Isolated TV surgery: ~20% of all TV surgeries (~5,000 over 10 years in US); patients significantly younger than transcatheter therapy recipients
Repair (ring annuloplasty — gold standard): Undersized ring effective for dilated annulus; DeVega suture-based largely abandoned for poor durability
Replacement: Mechanical vs bioprosthetic — similar 5-year outcomes; bioprosthesis durability approaching 15 years; mechanical may show earlier adverse events sources/TV-Mx-AHA-2024 high

ACC/AHA 2020 — Without left-sided valve disease requiring surgery:

Class I C: TV surgery in symptomatic patients with severe primary TR without severe RV dysfunction or severe PH sources/vhd-esc-2025 very high
Class IIa C: TV surgery in asymptomatic severe primary TR with RV dilatation/function deterioration (without severe RV/LV dysfunction or severe PH)
Class IIa B: TV surgery in symptomatic severe secondary TR or with RV dilatation/dysfunction (without severe LV/RV dysfunction or PH)

Concomitant TR with left-sided valve surgery (upgraded 2025):

Class I B (new): TV surgery recommended for severe primary or secondary TR at time of left-sided surgery
Class IIa B (new): TV repair should be considered for moderate primary or secondary TR to prevent progression and RV remodelling (supported by 2 recent RCTs)
Class IIb B (new): TV repair may be considered for mild secondary TR with annular dilatation (≥40 mm or >21 mm/m²) — weighed against increased pacemaker risk (up to 14% after annuloplasty) sources/vhd-esc-2025 very high

Transcatheter Tricuspid Treatment

Trial Data (AHA 2024 Scientific Statement)

TRILUMINATE Pivotal (RCT — TriClip TEER vs optimal GDMT, intermediate/high surgical risk):
- Win ratio 1.48 (95% CI 1.06–2.13; p=0.02) favouring TEER — hierarchical composite of death/TV surgery, HF hospitalisation, QoL improvement
- No significant difference in 1-year mortality or HF hospitalizations (annualised rate 0.21 vs 0.17 events/patient-year)
- KCCQ-12: +12 points (device) vs +0.6 (GDMT); p<0.001; greater benefit if residual TR ≤moderate or >1 grade reduction
- 87% had TR ≤moderate at 30 days
- TriClip G4 FDA-approved for symptomatic severe TR sources/TV-Mx-AHA-2024 high
PASCAL Precision: CLASP TR US EFS (n=34): 85% ≥1 grade TR reduction; 52% TR ≤moderate at 30 days; pivotal RCT ongoing sources/TV-Mx-AHA-2024 high
Cardioband annuloplasty (CE mark 2018): EFS (n=37): 83% success; 73% had ≥2 grade TR reduction at 1 year; 73% TR ≤moderate sources/TV-Mx-AHA-2024 high
EVOQUE transcatheter TV replacement: TRISCEND EFS (n=56): 98% procedural success; 98% TR mild or less at 30 days; 11% pacemaker; 3.6% 30-day mortality; FDA-approved based on TRISCEND II 6-month results sources/TV-Mx-AHA-2024 high
Heterotopic replacement (IVC/SVC): TricValve and TRICENTO systems; for high-risk patients with severe TR-related venous congestion without native TA intervention; early EFS data only sources/TV-Mx-AHA-2024 high

ESC 2025 Recommendations

Class IIa A (upgraded from IIb C): Transcatheter TV treatment should be considered to improve QoL and promote RV remodelling in high-risk patients with symptomatic severe TR despite optimal medical therapy, without severe RV dysfunction or pre-capillary PH
Evidence base: TRILUMINATE Pivotal, Tri.Fr (TEER + GDMT vs GDMT alone), TRISCEND II (replacement — similar QoL benefit, higher bleeding 15%, pacemaker ~25% in naive patients)
Transcatheter TV replacement reduces TR more completely than repair but has less favourable safety profile
All transcatheter TV procedures should be performed at experienced Heart Valve Centres with dedicated TV expertise
Careful anatomical eligibility assessment required: jet location, coaptation gap, leaflet tethering, CIED lead position sources/vhd-esc-2025 very high

Therapy Selection and Lifetime Management (AHA 2024)

No guidelines exist to determine repair vs replacement for individual patients — field still evolving
TEER may be difficult with large coaptation gaps (large annuli from AF/RV failure); requires high-quality imaging
Concern about complete sudden TR elimination in severe PH → acute RV failure and haemodynamic instability
Sequence matters: annuloplasty first may preserve future TEER/TTVR options; some TEER devices may preclude subsequent devices
CIED lead position must inform device choice and future pacing options
Liver function assessment mandatory before intervention (TR-related hepatic congestion vs intrinsic liver disease affects long-term outcomes)
Volume optimisation ("prehab" IV diuresis) before imaging/procedure for accurate anatomical assessment sources/TV-Mx-AHA-2024 high

Distinguish CIED-related TR (lead causing valve damage) from CIED-associated TR (incidental)
Lead repositioning or extraction may improve TR in selected patients; risk of additional valve damage is non-negligible
Transcatheter interventions may need to account for CIED leads in device sizing and implantation planning

Follow-up

Moderate or severe TR: clinical and echo follow-up at least every 6 months
After transcatheter intervention: close follow-up given high residual TR rates and ongoing RV remodelling process

ACC/AHA 2020 — TR Intervention Criteria

Class I B-NR: Severe TR undergoing left-sided valve surgery → concomitant TV surgery
Class IIa B-NR: Progressive TR (Stage B) undergoing left-sided surgery + annular dilation >4.0 cm OR prior right-HF → TV surgery beneficial
Class IIa B-NR: Symptomatic severe primary TR → isolated TV surgery to reduce symptoms and hospitalisations
Class IIa B-NR: Symptomatic severe isolated secondary TR from annular dilation (no PH/LV dysfunction) poorly responsive to medical therapy → isolated TV surgery beneficial
Class IIb C-LD: Asymptomatic severe primary TR with progressive RV dilation or dysfunction → TV surgery may be considered
Note: ACC/AHA 2020 does not include transcatheter TV treatment (no RCT evidence at time of publication); TRILUMINATE and TRISCEND II published after 2020 → ESC 2025 upgraded transcatheter TV to Class IIa A sources/VHD-AHA-2020 very high

Contradictions / Open Questions

No mortality benefit demonstrated in any RCT for transcatheter TR treatment — TRILUMINATE Pivotal win ratio was QoL-driven with no significant difference in 1-year mortality or HF hospitalizations sources/TV-Mx-AHA-2024 high; whether TR treatment modifies mortality remains unknown
Transcatheter TV replacement (TRISCEND II): QoL benefit similar to TEER but higher pacemaker rate (~11–25% in naive patients) and major bleeding (~15%) — optimal patient selection not defined sources/TV-Mx-AHA-2024 high vs sources/vhd-esc-2025 very high
Rhythm control and TR: Some patients experience TR reduction after successful rhythm control; evidence is not consistent — effect depends on underlying cause, atrial dilation, and other conditions sources/TV-Mx-AHA-2024 high
Concomitant TV repair for mild TR with annular dilatation: benefit may be offset by higher pacemaker implantation rate (up to 14% after annuloplasty), which is itself associated with worse long-term HF outcomes sources/vhd-esc-2025 very high
Optimal timing for isolated TV surgery remains debated — patients often referred too late when RV dysfunction is advanced and surgery carries prohibitive risk
AHA 2024 vs ESC 2025 transcatheter TV: AHA 2024 Scientific Statement describes TEER and EVOQUE as FDA-approved without formal class recommendations; ESC 2025 provides Class IIa A recommendation — both incorporate TRILUMINATE Pivotal and TRISCEND II data sources/TV-Mx-AHA-2024 high vs sources/vhd-esc-2025 very high
Long-term device durability: No transcatheter TV device has long-term durability data; TEER may limit future TTVR options depending on device deployed; annuloplasty may best preserve future options sources/TV-Mx-AHA-2024 high

Connections

Related to concepts/Valvular-Heart-Disease
Related to concepts/Secondary-Mitral-Regurgitation
Related to concepts/Primary-Mitral-Regurgitation
Related to concepts/Mitral-Stenosis
Related to concepts/RV-PA-Coupling — TAPSE/sPAP predicts post-intervention mortality in TR
Related to concepts/Structural-Valve-Deterioration — future durability concern for transcatheter TV devices
Related to concepts/Periprocedural-CIED-Management — CIED lead position informs transcatheter TV device choice
Related to entities/Atrial-Fibrillation
Related to entities/Heart-Failure
Related to entities/Pulmonary-Hypertension