Right ventricle assessment before tricuspid valve interventions

Abstract

In the latest ESC/EACTS Guidelines for the Management of Valvular Heart Disease, right ventricular dilatation and dysfunction, severe pulmonary hypertension and tricuspid annulus dilatation were reported to be the most important parameters to consider in patient selection for tricuspid valve interventions. Indeed, comprehensive right ventricular assessment is crucial in patients with severe tricuspid regurgitation who may benefit from transcatheter or surgical procedures. However, the only guideline parameter considered for intervention has been tricuspid annular dilatation in the presence of at least mild to moderate tricuspid regurgitation, with no other right ventricular markers used in the decision-making process for invasive treatment. Notably, challenges in the assessment of right ventricular function may limit establishing thresholds for defining right ventricular dysfunction. The aim of this review is to summarize current evidence on the prognostic significance of right ventricular function in patients with tricuspid regurgitation undergoing percutaneous or surgical interventions.

Introduction

In 2021, the ESC/EACTS Guidelines for the Management of Valvular Heart Disease for tricuspid regurgitation¹ emphasized the importance of assessing right ventricular function as well as pulmonary hypertension when evaluating patients with tricuspid regurgitation. Medical therapy (e.g. diuretics) and addressing underlying causes of secondary tricuspid regurgitation remain the cornerstone of treatment; however, further evidence is needed regarding the timing of invasive procedures, especially when considering transcatheter interventions and their potential benefit.

Right heart failure (RHF) plays an important role in the progression of tricuspid regurgitation.² Unfortunately, it is still rather difficult to define right ventricular dysfunction in patients with severe tricuspid regurgitation, with very few guideline-recommended parameters, such as a dilatation of the tricuspid valve (TV) annulus of more than 40 mm.

Evaluation of right ventricular dysfunction is challenging, as the right ventricule may be exposed to pressure and volume overload, myocardial ischemia, intrinsic myocardial disease, or pericardial constriction.³ In addition, right ventricular response after tricuspid valve surgery may vary due to multiple factors such as cause of tricuspid regurgitation, progression of the disease and extracardiac consequences.¹

The purpose of this review is to summarize current evidence on the prognostic significance of right ventricular function parameters in patients with tricuspid regurgitation proposed for percutaneous or surgical interventions, focusing on the relationship between the right ventricle and tricuspid regurgitation.

Right ventricular function in tricuspid regurgitation

For many years, the right ventricule was considered a transfer chamber, but in recent years, evidence has emerged of the importance of right ventricular systolic function and how it is influenced by significant tricuspid regurgitation. Right ventricular remodeling response leads to an initial volume overload and later on both volume and pressure overload as well as myocardial disease. Currently, it is known that right ventricular impairment is characterized by reduced longitudinal deformation and an increase in the circumferential component.^1–3

In addition to clinical examination, cardiovascular imaging represents the gold standard for assessing right ventricular remodeling in clinical practice.

Transthoracic echocardiography (TTE) is the first investigation that allows the assessment of the dimensions of the right cavities and right ventricular systolic function.

The most important measurements include right ventricular basal diameter, mid-level diameter, longitudinal diameter, RVOT proximal diameter, right ventricular distal diameter, right ventricular wall thickness (cut-off 5 mm), and right ventricular end-systolic and end-diastolic areas (ESA/EDA) that allow calculation of the right ventricular fractional area change (RV FAC).

A basal diameter of 41 and 35 mm at mid-level in the right ventricular focused view indicates right ventricular dilatation.⁴ Assessment of right ventricular systolic function includes the tricuspid annular plane systolic excursion (TAPSE – normal value over 16 mm), and the peak systolic velocity of the right ventricular free wall assessed by using pulsed-wave tissue Doppler DTI (S’TDI; normal value over 10 cm/s). These parameters evaluate the right ventricular longitudinal systolic function, and peak systolic motion (longitudinal shortening of myocardial cells).^5,6 Radial systolic function is assessed by the fractional area change (FAC), which is obtained from the apical four-chamber view and calculated similarly to the left ventricle ejection fraction but considering the right ventricular area as the difference between the end-diastolic area and the end-systolic area divided by the end-diastolic area [(EDA – ESA/EDA)].⁶ Systolic dysfunction is considered when the RV FAC is below 35%.⁵ Another significant echocardiographic right ventricular parameter is the right ventricular ejection fraction (RVEF), properly evaluated using 3D technology with a cut-off for a normal function of more than 44%.

Additional echocardiographic parameters indicating increased right ventricular pressures are right atrial volume, tricuspid and pulmonary regurgitation, pulmonary artery systolic pressure (PASP), inferior vena cava diameter with respiratory variations, and leftward shift of the interventricular septum.^5–7

Pulmonary arterial systolic pressure and its relationship with the TAPSE (TAPSE/PASP) have been described as an index of in-vivo right ventricular longitudinal shortening and is correlated with the right ventricular afterload. TAPSE/PASP has been validated as an independent and strong predictor of RHF and left ventricular heart failure^7–9 and as an important marker of severe tricuspid regurgitation.¹⁰ In addition, a dilated right ventricle and right atrium suggest a chronic state of right ventricular dysfunction.¹¹ One of the most significant right ventricular function parameters is the right ventricular global longitudinal strain (GLS) which is defined as the degree of myocardial longitudinal deformation relative to its original length and is expressed as a percentage. GLS has emerged as a technique to assess myocardial contractility.^4,10,12 A cut-off for the right ventricular global longitudinal strain of more than –20% is considered abnormal.¹²

Importantly, strain imaging techniques using 2D speckle tracking echocardiography or cardiac magnetic resonance (CMR) have been shown to be more sensitive than TAPSE or S’ in detecting early right ventricular dysfunction.^13–18

Longitudinal free-wall deformation of the right ventricle has emerged as a sensitive measure of right ventricular dysfunction, which has prognostic value in a broad spectrum of cardiovascular diseases.¹⁸

Therefore, 3D echocardiography can be used to calculate right ventricular volumes and is an alternative to CMR imaging, which remains the gold standard for calculating RVEF.¹³ Indeed, RVEF, stroke volume index, and right ventricular end-systolic volume index are informative measures for prognosis and risk stratification.¹⁴

Regarding invasive hemodynamic measurements, right heart catheterization allows detection of the pulmonary artery pulsatility index (PAPi).¹⁹ PAPi is the ratio between the pulmonary artery pulsatile pressure and the right atrial pressure (PASP – PADP/RAP) and has emerged as a predictor of right ventricular failure in patients with acute myocardial infarction and right ventricular involvement, cardiogenic shock, and in patients undergoing left ventricular assist device implantation. Importantly, low PAPi values (≤8.6) are also independently associated with poorer survival.^20,21

Regarding tricuspid regurgitation, determining the optimal timing for valvular correction, remains a real challenge in clinical practice. Adequate assessment of the right ventricule is crucial, in addition to other parameters used to quantify the severity of the regurgitation. The most important are the quantitative proximal isovelocity surface area (PISA) and the effective regurgitant orifice area [EROA > 40 mm², regurgitant volume (right ventricular > 45 ml), and vena contracta (> 7 mm)], used to determine the outcomes of severe tricuspid regurgitation in terms of repair probability and clinical benefit, and evaluation before and after severe tricuspid regurgitation repair should be necessary.²²

According to recent guidelines,¹ the treatment of severe tricuspid regurgitation is indicated considering cause, risk assessment, symptoms, or the need for left-sided surgery. Primary tricuspid regurgitation results from congenital abnormalities, infective endocarditis, rheumatic disease, carcinoid tumor, toxic effects, or myxomatous degeneration. In contrast, alterations of the right atrium and tricuspid annulus with subsequent dilatation, or remodeling of the right ventricular result in flap malcoaptation.²³ Usually, primary tricuspid regurgitation is responsible for right ventricular volume overload, right atrial dilatation, and consequently right ventricular dysfunction. The mechanism of severe primary tricuspid regurgitation is annular enlargement due to degenerative alteration of the fibrous structure.²⁴ Treatment of severe primary tricuspid regurgitation is indicated if symptomatic, and restorative surgery is preferable to percutaneous repair.^1,23 As for secondary tricuspid regurgitation, the guideline indication for repair considers either surgery associated with left-sided pathologies or right ventricular dilatation and first signs of dysfunction in case of isolated tricuspid regurgitation.^1,2,23

Therefore, it is of utmost importance to adequately diagnose and treat severe tricuspid regurgitation in the early stages of the disease, in order to avoid RHF.^24–29

Ingraham et al.²⁸ showed that patients with higher EROA, better right ventricular function, and more severe symptoms (dyspnea, fatigue, exertion intolerance, and right upper quadrant tension) were more likely to receive surgical treatment unlike patients with severe TR and significant comorbidities (e.g. severe pulmonary hypertension, end-stage renal disease).

Right ventricle function in patients surgically treated for tricuspid regurgitation

In severe tricuspid regurgitation, surgical correction is preferable to medical or percutaneous treatment.^1,2 For severe primary tricuspid regurgitation, tricuspid valve repair is preferable to replacement. Surgical intervention on the tricuspid valve is indicated either isolated or at the time of left-sided valve surgery.^1,2,30,31 In addition, tricuspid annuloplasty is the preferred technique due to its superior long-term results.⁸ However, patients with severe tricuspid regurgitation and right ventricular dilatation represent a challenging subgroup in tricuspid valve repair.

TV surgical replacement is associated with poor early and long-term outcomes, which may be related to late referral of patients in advanced stages of TV disease and right ventricular dysfunction rather than the intervention itself considering that tricuspid regurgitation is usually well tolerated for a long period of time. On the contrary, valvular repair is safer, and in most cases is concomitant to the treatment of left heart diseases.

Despite the high prevalence of significant tricuspid regurgitation and its acknowledged negative impact on prognosis, surgery is still performed in a minority of patients and this is due to late referral when surgical risk becomes extremely high. As a less invasive alternative to surgery, transcatheter tricuspid valve repair represents a promising therapeutic option to improve the quality of life of patients, especially for those at high surgical risk.

In this regard, Chikwe et al.³² reported improved right ventricular remodeling and reduced PASP in patients undergoing concomitant tricuspid annuloplasty for moderate tricuspid regurgitation and/or tricuspid annular dilatation associated with surgical mitral valve repair.

Moreover, in a multivariate analysis, it was found that tricuspid annuloplasty was independently associated with freedom from late recurrence of at least moderate tricuspid regurgitation (P = 0.04) being also an independent predictor of recovery of the right ventricular function (P = 0.02).

Furthermore, Calafiore et al.³⁰ demonstrated that tricuspid regurgitation annuloplasty is associated with worse surgical and survival outcomes in the presence of negative right ventricular remodeling (P < 0.01). Therefore, optimization of right ventricular function may allow patients with prohibitive right ventricular dysfunction to become better candidates for surgery and improved outcomes.^24,26,31 In fact, Dreyfus et al.³⁴ demonstrated that concomitant right ventricular dysfunction significantly increases in-hospital mortality during and after tricuspid regurgitation surgical treatment {odds ratio [OR] = 2.6 [confidence interval (CI), 1.2–5.8], P = 0.02}.

Yiu et al.³⁵ demonstrated that patients undergoing annuloplasty who had a more dilated right ventricule (area under the curve = 0.74; P < 0.01) and increased tethering area (area under the curve = 0.70; P = 0.04) tended to have more adverse events at 1-year follow-up.

Interestingly, in many cases, echocardiographic assessment lacks one or more parameters of right ventricular systolic function prior to surgery, but also after the surgical treatment.^32–37

Right ventricular dysfunction is an indicator of irreversible myocardial dysfunction. Patients with more severe right ventricular dysfunction were in worse clinical condition and had lower NYHA functional class. Postoperative mortality was increased in these patients despite tricuspid valve surgery and an improvement in right ventricular size and function, emphasizing once more the need for an early invasive approach.^37–41 TV repair should be encouraged in the decision-making process, considering not only annular dilatation but also the markers of right ventricular remodeling.³⁹

Prihadi et al.³¹ demonstrated worse survival in patients with reduced right ventricular GLS compared with those with preserved right ventricular GLS, as opposed to decreased right ventricular FAC (hazard ratio, 0.997; 95% CI, 0.977–1.117; P = 0.115) or TAPSE (hazard ratio, 0.988; 95% CI, 0.953–1.016; P = 0.396). TAPSE was significantly lower after the intervention, while the value of the RVFAC was not affected by surgery.

These results suggests that TAPSE is not a suitable parameter for assessing right ventricular function after surgical tricuspid annuloplasty. Therefore, FAC is a more reliable parameter to assess right ventricular systolic function after tricuspid annuloplasty instead of TAPSE.^10,13,42 Operative mortality is significantly increased in patients with severe tricuspid regurgitation and concomitant right ventricular systolic dysfunction who appear to be in worse clinical condition³⁷ (Table 1).

Table 1.

Evaluation of right ventricular function as a predictor of mortality in preoperative and postoperative in severe tricuspid regurgitation surgical treatment

Study	Patients involved	TR repair or replacement	Parameters of RV function	HR for mortality in patients with RV disfunction	Outcomes
Ingraham et al.28	9	Both	TAPSE, PASP	No	Better RV function despite symptoms and EROA is the most important parameter for TR surgical treatment and survival (P = 0.320)
Calafiore et al.30	688	Repair	TAPSE, S’TDI, RVBD RVMD, PASP	2.316 (95% CI, 1.172–4.574) P = 0.015	Parameters considered for RV remodeling show RV remodeling before TR annuloplasty worsens surgical and survival outcomes
Prihadi et al.31	1292	Both	TAPSE, S’TDI, RVBD RVMD, PASP, FAC, GLS	1.029; 95% CI, 1.010–1.049; P = 0.003	The presence of RV systolic dysfunction before severe TR treatment is responsible for worse clinical outcomes despite RV dilatation
Dreyfus et al.34	466	Both	TAPSE, S’TDI, RVBD, PASP	OR = 2.6 (1.2–5.8), P = 0.02	Concomitant RV disfunction increased mortality during and after TR surgical treatment
Yu et al.35	74	Repair	EDA, ESA, FAC, RV basal/midcavity/longitudinal diameter	HR = 2.24 (1.39–3.61) P < 0.01	RV midcavity diameter was associated with adverse events at the 1-year follow-up
Dreyfus et al.36	148	Repair	Absent	Absent	Absence of evaluation
Fukunaga et al.37	14	Both	Absent	Absent	Absence of evaluation
Subbotina et al.38	191	Reparation	TAPSE	TAPSE: OR 0.859 (95% CI, 0.75–0.98) P = 0.026	RV reduced is a parameter of perioperative mortality

EDA, end-diastolic area; ESA, end-systolic area; FAC, fractional area change; GLS, gold longitudinal strain; PASP, pulmonary artery systolic pressure; RV, right ventricle; RVBD, RV basal diameter (mm) RVMD:RV mid-diameter; S’TDI, peak systolic velocity of tricuspid annulus by pulsed-wave DTI; TAPSE, tricuspid annular plane systolic excursion.

Right ventricular function in patients treated minimally invasively (percutaneous transcatheter interventions)

According to current guidelines, percutaneous treatment of severe tricuspid regurgitation has an indication for patients with secondary tricuspid regurgitation, without severe biventricular dysfunction or pulmonary hypertension, considered unsuitable for surgery by an expert multidisciplinary team.^1,2,23

Changes in the structure of the tricuspid flap or annulus associated with right ventricular remodeling are reciprocal and can lead to increased tricuspid regurgitation and further right ventricular dilatation, especially in patients with heart failure. Percutaneous treatment of severe tricuspid regurgitation has emerged as the therapeutic option for patients presenting with frequent hospitalizations for decompensated heart failure and at high surgical risk.

The TRILUMINATE study⁴³ showed that the transcatheter edge-to-edge tricuspid repair system is well tolerated and effective in reducing tricuspid regurgitation.

The severity of tricuspid regurgitation was reduced by at least one grade at 30 days in 86% of patients undergoing a transcatheter edge-to-edge tricuspid repair system.

The reduction of tricuspid regurgitation was associated with significant clinical improvement at 6 months post procedure through its positive right heart remodeling. In addition, the transcatheter edge-to-edge tricuspid repair system, especially TriClip, compared with medical therapy, improved the right ventricular end-diastolic dimension (P < 0.0001) and TAPSE (P = 0.015) in patients with severe tricuspid regurgitation.

The multinational TriValve registry⁴⁴ demonstrated that different transcatheter tricuspid valve interventions (Trialign, TriCinch, FORMA, Cardioband, and caval valve implantation) are associated with a lower incidence of the composite endpoint of death and rehospitalization and individual outcomes. These results suggest transcatheter tricuspid valve therapy is feasible with different techniques, although patients undergoing transcatheter tricuspid valve therapy are currently at high risk, with a functional cause and very severe central regurgitation.

Regarding Cardioband, several studies^45,46 evaluated the right ventricular reverse remodeling in severe-to-massive tricuspid regurgitation patients after tricuspid valve repair through percutaneous annuloplasty using the Cardioband system and demonstrated no statistically significant changes in TAPSE and FAC.

On the other hand, in the TriBAND study,⁴⁷ there was a significant improvement in Mid and Base-RV end-diastolic diameter, TAPSE and PASP in patients with severe tricuspid regurgitation undergoing tricuspid valve repair through percutaneous annuloplasty using the Cardioband system, at discharge and after 30 days of treatment.

Ingraham et al.²⁸ found that TAPSE had greater value in the intervention group compared with the medically managed group (0.11 ± 0.04 vs. 0.09 ± 0.03 mm, P = 0.013). Still, a clear position on its predictive value associated with outcomes on right ventricular function in the interventional group was not established. Karam et al.⁴⁸ noted that several parameters such as TAPSE, right ventricular FAC, and PASP did not influence the rate of procedural success and there was no difference in the combined endpoint of survival free from hospital admission for heart failure at 1 year compared to baseline TAPSE (P = 0.041). Schlotter et al.⁴⁹ demonstrated improved survival in patients undergoing percutaneous repair with mid-range right ventricular function (evaluated using TAPSE, range 13–17 mm) (Table 2).

Table 2.

RV function in preoperative and postoperative in severe tricuspid regurgitation percutaneous treatment

Study	Patients involved	Parameters of RV function	HR for mortality in patients with RV disfunction	Significant changes of TAPSE before and after TR treatment
Ingraham et al.28	13	TAPSE, PASP	No	Yes, TAPSE 0.11 ± 0.04
Muntané-Carol et al.29	300	TAPSE, S’TDI, PASP	No	No, HR 0.98 (95% CI, 0.91–1.06) P = 0.677
Nickenig44	85	TAPSE, S’TDI, RVBD RVMD, PASP, GLS	No	Yes, P = 0.015
Nickenig et al.48	61	RVMD, RVBD, TAPSE, PASP, FAC	No	P < 0.001
Karam et al.49	249	TAPSE, PASP, FAC	No	No, P = 0.041
Perlman et al.52	18	TAPSE, S’TDI, RVBD RVMD, PASP	No	No, P = 0.12
Schlotter et al.53	684	TAPSE, PASP	0.22 (95% CI, 0.09, 0.57).	Only for TAPSE 13--17
Hahn et al.55	15	TAPSE, S’TDI, FAC, PASP	No	No, P = 0.31

FAC, fractional area change; GLS, gold longitudinal strain; PASP, pulmonary artery systolic pressure; RV, right ventricle; RVBD, RV basal diameter (mm) RVMD:RV mid-diameter; S’TDI, peak systolic velocity of tricuspid annulus by pulsed-wave DTI; TAPSE, tricuspid annular plane systolic excursion.

On the contrary, in the study conducted by Muntané-Carol et al.,²⁹ TAPSE and PASP were not significantly different before and after intervention [TAPSE hazard ratio 0.98 (95% CI, 0.91–1.06) P = 0.677, PASP hazard ratio 0.99 (95% CI, 0.97–1.005) P = 0.193]. Furthermore, Weckbach et al.⁵⁰ evidenced right ventricular reverse remodeling (RVRR) throughout a significant reduction of right ventricular end-diastolic volume (RV-EDV, P < 0.0001) and right ventricular end-systolic volume (RV-ESV, P = 0.049) measured by computed tomography (CT) in patients with severe tricuspid regurgitation undergoing transcatheter tricuspid valve replacement (TTVR) with the EVOQUE system (Edwards Lifesciences; you should describe that this is a prosthesis and not a repair technique). For new transcatheter device therapies, Perlman et al.⁵¹ highlighted that after 1 year of implantation of the FORMA transcatheter tricuspid spacer device, there was a significant improvement in right ventricular function at 1-year follow-up evaluated through TAPSE, S’TDI, RVBD RVMD, PASP. It is demonstrated that percutaneous tricuspid valve intervention reduces mortality and improves right ventricular function which is considered an independent predictor of mortality before and after tricuspid regurgitation intervention.^29,43–55

Discussion

Right ventricular dysfunction is an important predictor of survival and functional capacity.^50–53 Several studies have demonstrated that severe right ventricular dysfunction is associated with poor outcomes in patients with severe tricuspid regurgitation.^4–25

More research is needed to determine the ideal parameters to adequately characterize right ventricular systolic function prior to invasive procedures addressing tricuspid regurgitation. In most of the mentioned clinical trials, mainly TAPSE was used in the assessment of right ventricular dysfunction associated with severe tricuspid regurgitation. However, TAPSE is a parameter with several limitations such as the fact that it does not reflect right ventricular function after cardiac surgery and the fact that it only evaluates longitudinal function.^4,10,12

In terms of parameters prior to tricuspid interventions, larger EROA, better right ventricular function and functional impairment were more common in patients receiving tricuspid regurgitation intervention.^26–30

The interventional treatment of tricuspid regurgitation is often associated with left ventricular dysfunction and concomitant mitral regurgitation.¹ Interestingly, in their studies, Dreyfus et al.³⁴ and Fukunaga et al.³⁷ pay special attention to left ventricular disfunction before and after cardiac surgery but do not include specific right ventricular parameters in the echocardiographic assessments.

Right ventricular systolic function usually deteriorates postoperatively, but there is a tendency to improve during follow-up regardless of tricuspid annuloplasty, whereas diastolic function worsened in patients with tricuspid annuloplasty. Right ventricular diastolic function may potentially be impaired when tricuspid regurgitation correction by annuloplasty is performed at the time of left-sided surgery.^{1,2,15,30,36–41}

Ideally, right ventricular systolic function requires the inclusion of newer parameters such as GLS, RVFAC, or RVEF. Echocardiography is of paramount importance in the planning of tricuspid regurgitation procedures, as well as during intervention and on follow-up, for both surgical and transcatheter techniques.^56–58

Nowadays, a recent score for tricuspid regurgitation, the TRI-SCORE,⁵⁸ was proposed to evaluate the risk of isolated tricuspid regurgitation treatment. One of the eight parameters of the TRI-SCORE (age ≥70 years, NYHA functional Class III–IV, right-sided heart failure signs, daily dose of furosemide ≥125 mg, glomerular filtration rate <30 ml/min, elevated total bilirubin, left ventricular ejection fraction <60%, moderate/severe right ventricular dysfunction) was the presence of moderate/severe right ventricular dysfunction that was statistically associated with in-hospital mortality as lower TAPSE and S’TDI values (TAPSE < 17 mm, S’TDI < 9.5 cm/s, univariate analysis for predicting in-hospital mortality: Moderate/severe right ventricular dysfunction P = 0.002; TAPSE P < 0.001 S’TDI and PASP P = 0.001). Previously, the presence of right ventricular dysfunction had not been included in other scores for tricuspid regurgitation assessment (STS, EUROSCORE, EUROSCORE II). However, surgery for isolated tricuspid regurgitation remains rarely performed.

Therefore, percutaneous treatment of severe tricuspid regurgitation has shown long-lasting efficacy, improvement in symptom status and low rates of mortality and hospitalizations for heart failure. In certain scenarios emphasized in clinical trials, it could be indicated rather than surgery.^43–47 The evidence of right ventricular reverse remodeling was independently associated with improved survival especially in elderly patients with heart failure.^1–4

More randomized clinical trials are required in order to properly predict outcomes and the prognostic impact of right ventricular dysfunction in patients with severe tricuspid regurgitation (Fig. 1). Improvement in right ventricular parameters after tricuspid regurgitation correction should be evaluated by using new techniques such as CMR (gold standard for evaluating right ventricular size, volumes, ejection fraction, mass, and fibrosis), 3D echography, and spackle tracking techniques.

Fig. 1.

Parameters for evaluating the function of the right ventricle in case of surgery or percutaneous approach in the treatment of the tricuspid valve. BD, basal diameter; EDA, end-diastolic area; EF, ejection fraction; ESA, end-systolic area; FAC, fractional area change; GLS, gold longitudinal strain; PAPi, pulmonary artery pulsatility index; PASP, pulmonary artery systolic pressure; RV, right ventricle; S’TDI, peak systolic velocity of tricuspid annulus by pulsed-wave DTI; TAPSE, tricuspid annular plane systolic excursion.

Conclusion

Adequate assessment of right ventricular function in patients with severe tricuspid regurgitation remains challenging. This is mainly due to the fact that right ventricular systolic function per se requires a complex evaluation based not only on multiple parameters, but also on a comprehensive, integrative approach including echocardiographic and magnetic resonance techniques. Proper right ventricular systolic function assessment is of utmost importance, as right ventricular dysfunction was associated with poor outcomes in patients with severe tricuspid regurgitation within the ranges of normal. TAPSE less than 16 mm has been related to increased risk of hospitalization and recurrence of significant tricuspid regurgitation. Further research is needed in order to determine the role of GLS and 3D echocardiography prior to and after tricuspid surgery. No studies have assessed the role of strain and 3D assessment in patients undergoing surgery for tricuspid regurgitation.

In patients treated percutaneously, right ventricular function assessment allows a prognostic stratification but more evidence from RCTs is required. Interestingly, even in patients treated with transcatheter techniques, severe right ventricular dysfunction was associated with poor outcomes. New imaging techniques, such as CMR, for assessing both right ventricular function and tricuspid regurgitation severity may lead to better risk stratification models and patient selection. The right ventricle itself should be regarded as a crucial component in the therapeutic management of patients with severe tricuspid regurgitation.

Conflicts of interest

M. Adamo, and M. Gavazzoni received speaker honoraria from Abbott. M. Metra received consulting honoraria n the last three years from Abbott Structural Heart, Astra-Zeneca, Bayer, Boheringer Ingelheim, Edwards LifeSciences, Roche Diagnostics. Other authors have none to declare.