Revisit of Functional Tricuspid Regurgitation; Current Trends in the Diagnosis and Management

Current Unmet Needs and Clues to the Solution in the Management of Tricuspid Regurgitation

The clinical importance of tricuspid regurgitation (TR) has been recently highlighted. However, there remain several unmet needs with the diagnosis and treatment of TR. The major dilemma is a delayed treatment decision and an intervention at an advanced stage. Other important unmet needs are limitations in diagnostic imaging modalities, ambiguity in the guidelines regarding the interventional criteria, high surgical mortality, uncertainty in the reversibility of the right ventricle, and lack of long-term clinical data after the intervention. We have discussed such overall aspects of TR, the problems frequently experienced by clinical physicians and future strategies to improve the treatment of TR.

Although tricuspid regurgitation (TR) is a general medical issue with growing prevalence and socioeconomic burden, most clinicians have not paid much attention to TR in the past. Several problems of TR have been pointed out in clinical practice, which include: ambiguous clinical manifestations and the difficulty in initial detection, limitations in generally used diagnostic tools, the absence of objective criterion for therapeutic intervention, high operative morbidity and mortality, and lack of long-term clinical data after the intervention for TR. Therefore, patients with TR usually visit clinicians at a much-advanced state, and this delay gives a major dilemma in clinical decision-making in a routine clinical practice. To improve the clinical outcome of TR, we need more knowledge about TR for solving the current problems and making strategies for better clinical practice. With this background, we have discussed in the present article about the pathophysiology of TR and the problems frequently experienced by clinical physicians in the diagnosis and treatment of TR. Furthermore, we have discussed the future strategy to improve the treatment of TR.

Recent advances in multimodality imaging of the tricuspid valve

INTRODUCTION

The tricuspid valve (TV) and the right heart chambers are complex three-dimensional structures that are difficult to assess using tomographic imaging techniques. The progressive aging of the general population and the advancements in treating left-sided heart diseases by transcatheter procedures have contributed to the tricuspid regurgitation (TR) becoming a major public health problem associated with progression to refractory heart failure and poor outcome. Recent advances in multimodality cardiac imaging allow a better understanding of the pathophysiology of TR that may translate in better management of patients.

AREAS COVERED

Three-dimensional echocardiography, cardiac magnetic resonance, and computed tomography provide complementary information to i. assess the TV complex; ii. identify the etiology and the mechanisms of TR; iii. evaluate its severity and hemodynamic consequences; iv. explore the remodeling of the right heart chambers; and v. properly plan, guide, and monitor the transcatheter interventions aimed to reduce the severity of TR.

EXPERT OPINION

We need thorough understanding of both the TV and the right heart chamber geometry and function to understand the pathophysiology of TR. The integrated use of multimodality cardiac imaging is pivotal to assess patients with TR and to identify tailored and timely treatment of TR in properly selected patients.

Assessment of tricuspid annulus: anatomic and echocardiographic correlation

Tricuspid regurgitation is associated with a poor outcome and its quantification remains a challenge. Tricuspid annulus dilatation is one of the parameters that influences clinical decision-making. The aim of this study was to compare the use of 2D transoesophageal echocardiography with surgical assessment for the measurement of the tricuspid annulus. Sixty-one cardiac patients (median age 64 years) were included in the study. Echocardiographic tricuspid annulus measurements were obtained from four chamber and transgastric short axis views and compared with the surgical measurements of this valve. The study was approved by the Ethics Committee of our institution. The tricuspid annulus measurements were obtained from the four chamber and the short axis views in 57 and 49 patients, respectively, while surgical measurement was performed in all 61 patients. Bland-Altman analysis of 49 tricuspid annulus-matched dimensions of the short axis view and surgical values showed a mean bias of 0.223 mm/m², with limits of agreement of -5.86 to 6.31 mm/m². Echocardiographic measurements of the tricuspid annulus dimension were accurate (90% sensitivity and 90% specificity for a four chamber view cut-off value ≥ 24.5 mm/m², and 89% sensitivity and 97% specificity for a short axis view cut-off value ≥ 37.6 mm/m², P < 0.0001; both cases) for detecting directly assessed annular dilatation by the surgeon in the operative field. Echocardiographic values of tricuspid annulus dimension have a good predictive value to detect surgically assessed annular dilatation and may help identify patients who require surgical tricuspid intervention.

Tricuspid annulus cinching force under pulmonary hypertensive right ventricle conditions: An ex vivo study

This study investigates the force required to reduce or "cinch" the tricuspid annulus under elevated right ventricular pressures, commonly seen in patients with pulmonary hypertension. Tricuspid regurgitation affects 1.6 million Americans. Approximately 43% of patients who undergo tricuspid valve repair to correct tricuspid regurgitation will develop residual pulmonary hypertension, putting them at risk for developing increased right ventricle pressures. Previous studies have quantified the forces required to cinch the tricuspid annulus by only pressurizing the right ventricle, leaving out forces from the pressurized left ventricle and septal wall unaccounted for. This study pressurized both left and right ventricles of 10 porcine hearts to their normal physiological pressures of 110 mmHg and 30 mmHg respectively, then increased right ventricular pressures to mimic moderate and severe pulmonary hypertension. A suture was anchored around the free wall of the tricuspid annulus with the free end attached to a force transducer. The force transducer was mounted on a slider system which pulled the suture at regular intervals. The cinching force on the tricuspid annulus was quantified with each annular reduction by simulating peak systole condition in both ventricles. The data was compared with only the right ventricle pressurized as previous studies did. There were significant differences in required cinching forces with each increase in right ventricular pressure and between trials that pressurized both ventricles versus only the right ventricle, suggesting adoption of this physiologically improved protocol. We also found with increased cinching of the tricuspid annulus, notable changes occur in the mitral annulus.

Tricuspid annular dilation in patients undergoing early mitral valve surgery: is it an old story?

Patients with mitral valve prolapse (MVP), undergoing early surgery for severe regurgitation, are usually characterized by a low degree of right chambers' remodeling. In this selected population, the mechanisms leading to tricuspid annular (TA) dilatation (TAD) are not well understood. In this setting, we aimed to evaluate, using three-dimensional echocardiography (3DE), how right chambers affect TA size and might contribute to functional tricuspid regurgitation (FTR) progression. We studied 159 patients treated with early isolated surgery for MVP, characterized by: sinus rhythm; normal biventricular function; normal or elevated pulmonary artery pressure; tricuspid regurgitation (TR) ≤ mild; no concomitant cardiac disease. All patients reached a 3-year echocardiographic follow-up. Based on two-dimensional echocardiography, patients were divided in Group 1 (N = 68, 43%, TAD, TA ≥ 21 mm/m²) and Group 2 (N = 91, 57%, no TAD, TA < 21 mm/m²). By 3DE, Group 1 showed larger TA size, right atrial (RA) volume and right ventricular (RV) conical remodeling compared to Group 2 (p < 0.05). The multivariate analysis revealed that RA volume, RV basal diameter and function were independently correlated to TA size (p < 0.05). At the 3-year follow-up there was a low incidence of FTR, with a trend towards FTR progression in Group 1 (p = 0.07). In patients undergoing early surgery for MVP, TAD seems to result from distinctive early-onset geometrical changes of the right chambers, preceding TR, RV dilatation and pulmonary hypertension at rest. An integrated approach, including right chambers' assessment by 3DE, might help to better recognized patients at higher risk for TAD and, potentially for FTR.

Tricuspid regurgitation in ischemic mitral regurgitation patients: prevalence, predictors for outcome and long-term follow-up

Background

Functional tricuspid regurgitation (FTR) is common in left-sided heart pathology involving the mitral valve. The incidence, clinical impact, risk factors, and natural history of FTR in the setting of ischemic mitral regurgitation (IMR) are less known.

Method

We conducted a cohort study based on data collected from January 2012 to December 2014. Patients diagnosed with IMR were eligible for the study. The median follow-up was 5 years. The primary outcome is defined as FTR developing at any stage.

Results

Among the 134 IMR patients eligible for the study, FTR was detected in 29.9% (N = 40, 20.0% mild, 62.5% moderate, and 17.5% severe). In the FTR group, the average age was 60.7 ± 9.2 years (25% females), the mean LV ejection fraction (LVEF) was 37.3 ± 6.45 [%], LA area 46.4 ± 8.06 (mm²), LV internal diastolic diameter (LVIDD) 59.6 ± 3.94 (mm), RV fractional area change 22.3 ± 4.36 (%), systolic pulmonary artery pressure (SPAP) 48.4 ± 9.45 (mmHg). Independent variables associated with FTR development were age ≥ 65y [OR 1.2], failed revascularization, LA area ≥ 42.5 (mm²) [OR 17.1], LVEF ≤ 24% [OR 32.5], MR of moderate and severe grade [OR 419.4], moderate RV dysfunction [OR 91.6] and pulmonary artery pressure of a moderate or severe grade [OR 33.6]. During follow-up, FTR progressed in 39 (97.5%) patients. Covariates independently associated with FTR progression were lower LVEF, RV dysfunction, and PHT of moderate severity. LA area and LVIDD were at the margin of statistical significance (p = 0.06 and p = 0.05, respectively).

Conclusion

In our cohort study, FTR development and progression due to IMR was a common finding. Elderly patients with ischemic MR following unsuccessful PCI are at higher risk. FTR development and severity are directly proportional to LV ejection fraction, to the extent of mitral regurgitation, and SPAP. FTR tends to deteriorate in the majority of patients over a mean of 5-y follow-up.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-01982-y.

Dynamic Systolic Changes in Tricuspid Regurgitation Vena Contracta Size and Proximal Isovelocity Surface Area in Hypoplastic Left Heart Syndrome: A Three-Dimensional Color Doppler Echocardiographic Study

BACKGROUND

The aims of this study were to investigate the dynamic changes in the vena contracta (VC) and proximal isovelocity surface area (PISA) through systole in patients with hypoplastic left heart syndrome and tricuspid regurgitation and to identify the stage of systole (early, mid, or late) in which VC and PISA radius are optimal.

METHODS

Twenty-eight patients with hypoplastic left heart syndrome were prospectively studied using continuous two-dimensional (2D) and three-dimensional (3D) echocardiography. Two-dimensional VC width, 3D VC area, and PISA radii (2D and 3D) were measured frame by frame throughout systole. The maximal 2D VC width, 3D VC area, and PISA radii in the first, middle, and last thirds of systole were compared, and correlations were explored with 3D tricuspid annular areas, right atrial volumes, and right ventricular volumes.

RESULTS

In all, 35 data sets that met inclusion criteria were analyzed. On frame-by-frame analysis, maximal 2D VC width and 3D VC area were found in the first third of systole in 17% and 20% of studies, in the second third in 34% and 31%, and in the final third in 49% and 49%. Similarly, the maximal 2D and 3D PISA radii were found in the first third of systole in 26% and 17% of studies, in the second third in 28% and 34%, and in the final third in 46% and 49%.

CONCLUSIONS

In hypoplastic left heart syndrome, detailed temporal analysis of tricuspid regurgitation-associated VC and PISA by 2D and 3D echocardiography reveals no reliable pattern predicting when in systole these parameters peak. Frame-by-frame measurement is necessary for identification of maximal VC and PISA radius on 2D and 3D color Doppler echocardiography because the severity of tricuspid regurgitation could be underestimated because of temporal variability in VC and PISA.

Refining Severe Tricuspid Regurgitation Definition by Echocardiography with a New Outcomes-Based "Massive" Grade

BACKGROUND

Current echocardiographic guidelines recommend that tricuspid regurgitation (TR) severity be graded in three categories, following assessment of specific parameters. Findings from recent trials have shown that the severity of TR frequently far exceeds the current definition of severe. We postulated that a grading approach that emphasizes outcomes could be useful to identify patients with severe TR at increased risk of mortality.

METHODS

We identified 284 patients with echocardiograms demonstrating severe functional TR, defined as vena contracta (VC) ≥ 0.7 cm. Demographics and mortality data were obtained from the medical records. Patients were divided into study (n = 122 patients with three-dimensional images) and validation (n = 162) cohorts. The VC was measured in both the right ventricular (RV) inflow and apical four-chamber views and averaged. For the study cohort, tricuspid annular, RV end-diastolic (basal, mid, long axis) dimensions, tricuspid leaflet tenting height and area, RV free-wall longitudinal strain, and RV volumes were measured from two- and three-dimensional data sets. A K-partition algorithm was used in the study cohort to derive a mortality-related cutoff VC value, above which TR was termed "massive." The ability of this VC cutoff to identify patients at greater mortality risk was then tested in the validation cohort using Kaplan-Meier survival analysis.

RESULTS

In the study cohort, VC > 0.92 cm (massive TR) was optimally associated with worse survival. Tricuspid annular and RV size were larger in the massive group (P < .05), while there were no significant differences in demographics between the TR groups. Importantly, in the independent validation cohort, the above VC cutoff also correlated with increased mortality in the massive group (log-rank P < .05).

CONCLUSIONS

Among patients traditionally defined as having severe TR, a subset exists with massive TR, resulting in greater adverse RV remodeling and increased mortality. These patients may derive the greatest benefit from emerging percutaneous therapies.

Multimodality Imaging of the Tricuspid Valve and Right Heart Anatomy

The characterization of tricuspid valve and right-heart anatomy has been gaining significant interest in the setting of new percutaneous transcatheter interventions for tricuspid regurgitation. Multimodality cardiac imaging provides a wealth of information about the anatomy and function of the tricuspid valve apparatus, right ventricle, and right atrium, which is pivotal for diagnosis and prognosis and for planning of percutaneous interventions. The present review describes the role of echocardiography, cardiac magnetic resonance, and multidetector row cardiac computed tomography for right heart and tricuspid valve assessment.

3-Dimensional Echocardiography in Imaging the Tricuspid Valve

Tricuspid regurgitation (TR) is an independent predictor of death. Lately, emerging technologies for the treatment of TR have increased the interest of physicians. Due to the complex 3-dimensional (3D) geometry of the tricuspid valve (TV) and its anterior position in the mediastinum, conventional 2D echocardiography is unsuitable to study the anatomy and pathophysiologic mechanisms of the regurgitant TV. 3D echocardiography has emerged as a very cost-effective imaging modality with which to: 1) visualize the TV anatomy; 2) define the mechanism of TR; 3) measure the size and geometry of the tricuspid annulus; 4) analyze the anatomic relationships between TV apparatus and surrounding cardiac structures; 5) assess volumes and function of the right atrium and ventricle; and 6) plan surgical repair or guide and monitor transcatheter interventional procedures.

Valve Disease in Heart Failure: Secondary but Not Irrelevant

Secondary regurgitation caused by the remodeling and dysfunction of the left or right heart chamber may complicate heart failure, worsening both symptoms and prognosis. Outcome studies have shown that patients' prognosis worsened as the severity of secondary regurgitation increases. Imaging and more specifically echocardiography plays a central role for diagnosis and serial assessment of secondary regurgitation as well as for timing the intervention and guiding the procedure.

Functional Tricuspid Regurgitation in Mitral Valve Disease

Functional tricuspid regurgitation is a common finding in patients with left-sided heart disease. If left untreated, it may reduce survival, limit functional capacity and cause end-organ dysfunction. Annulus dilation and leaflet tethering due to right ventricle remodeling are 2 major pathophysiologic mechanisms in functional tricuspid regurgitation. Even if surgical treatment remains the gold standard, indication and timing of surgical interventions remain the object of debate in the medical community. More recently, numerous transcatheter therapies have been developed in order to offer less invasive options to patients who otherwise would have a high risk of mortality and morbidity with surgical interventions.

3D printing of normal and pathologic tricuspid valves from transthoracic 3D echocardiography data sets

Aims

To explore the feasibility of using transthoracic 3D echocardiography (3DTTE) data to generate 3D patient-specific models of tricuspid valve (TV).

Methods and Results

Multi-beat 3D data sets of the TV (32 vol/s) were acquired in five subjects with various TV morphologies from the apical approach and analysed offline with custom-made software. Coordinates representing the annulus and the leaflets were imported into MeshLab (Visual Computing Lab ISTICNR) to develop solid models to be converted to stereolithographic file format and 3D print. Measurements of the TV annulus antero-posterior (AP) and medio-lateral (ML) diameters, perimeter (P), and TV tenting height (H) and volume (V) obtained from the 3D echo data set were compared with those performed on the 3D models using a caliper, a syringe and a millimeter tape. Antero-posterior (4.2 ± 0.2 cm vs. 4.2 ± 0 cm), ML (3.7 ± 0.2 cm vs. 3.6 ± 0.1 cm), P (12.6 ± 0.2 cm vs. 12.7 ± 0.1 cm), H (11.2 ± 2.1 mm vs. 10.8 ± 2.1 mm) and V (3.0 ± 0.6 ml vs. 2.8 ± 1.4 ml) were similar (P = NS for all) when measured on the 3D data set and the printed model. The two sets of measurements were highly correlated (r = 0.991). The mean absolute error (2D - 3D) for AP, ML, P and tenting H was 0.7 ± 0.3 mm, indicating accuracy of the 3D model of <1 mm.

Conclusion

Three-dimensional printing of the TV from 3DTTE data is feasible with highly conserved fidelity. This technique has the potential for rapid integration into clinical practice to assist with decision-making, surgical planning, and teaching.

Tricuspid valve repair with Dacron band versus DeVega or segmental annuloplasty. Hospital outcome and short term results

BACKGROUND

The purpose of this study was to compare the hospital outcome and short term results of tricuspid valve (TV) repair with three repair techniques for functional tricuspid regurgitation (TR), namely, flexible Dacron band, DeVega and segmental annuloplasty.

METHODS

A total of 60 patients underwent TV repair at National Heart Institute from January 2013 to November 2014, of which 20 had DeVega procedure (DV), 20 had a segmental annuloplasty (SA) procedure and 20 had a Dacron band (DB) procedure. Concomitant procedures done for rheumatic left sided valve pathology consisted of mitral valve replacement in 70% of patients, and double valve replacement in 30% of patients. Clinical and echocardiographic follow-up data were obtained. Follow-up was 100% complete and was concluded after one year.

RESULTS

All demographic criteria and preoperative characteristics of the three studied groups were comparable except for preoperative right ventricular (RVEDD) size that was significantly bigger in Dacron band group as compared to the other two groups (3.18 ± 0.43 cm compared to 3.00 ± 0.33 cm (DV) and to 2.88 ± 0.35 cm (SA), p value of (0.045)). Similarly, all operative and postoperative criteria were comparable among the study groups. Noticeably, (RVEDD) size remodeled better postoperatively in (DB) group as compared to the other two groups, (2.54 ± 0.26 cm compared to 2.83 ± 0.311 cm (DV) and to 2.72 ± 0.29 cm (SA), mean difference values were group (0.64 ± 0.47 cm) for (DB) compared to (0.18 ± 0.29 cm) for (DV) or to (0.16 ± 0.45 cm) for (SA) with p value of 0.000. The majority of patients in each group did not have tricuspid regurgitation (TR) or mild degree (+1) of (TR) on discharge. After one year of follow-up, most of the patient had either no regurgitation or grade (+1 TR). Two patients (10%) in DV group and one patient (5%) in SA group had (+3 TR). There was no statistical significance in the incidence of hospital mortality, only one patient died in DB and one in DV group (5%) and no death happened after hospital mortality for the three groups after one year.

CONCLUSIONS

The three techniques are options to repair the tricuspid valve, however, placement of Dacron band in patients undergoing tricuspid valve repair is associated with better RV remodelling, and hence, a probable better right ventricular performance and better outcome of repair is expected. A higher number of patients are needed with longer follow up period to appreciate the effect on survival and rate of freedom from tricuspid regurgitation and re-intervention.

[Hemodynamic interplay between tricuspid valve and right ventricle]

The tricuspid valve and the right ventricle are hemodynamically closely related. Pathological changes of the valve or of the ventricle itself and also various diseases beyond that can result in a downward spiral of mutual interference, which is of prognostic importance for the patient. The development of a functional tricuspid regurgitation is of great importance. Especially with the help of 3D-echocardiography, more and more changes and mechanisms have been identified that are crucial in this process. This article provides a review of the relationship between the tricuspid valve and the right ventricle emphasizing the current knowledge of the causes, the pathophysiological concepts, the underlying structural changes and the therapeutic approaches based on this.

Role of 3D Echocardiography in Cardiac Surgery: Strengths and Limitations

PURPOSE OF REVIEW

This review aims to highlight the general and specific strengths and limitations of intraoperative 3D echocardiography. This article explains the value of real-time three-dimensional transesophageal echocardiography (RT 3D TEE) during cardiac surgery and cardiac interventions.

RECENT FINDINGS

Recently published recommendations and guidelines include the use of RT 3D TEE. RT 3 D TEE provides additional value particularly for guidance during cardiac interventions (i.e., transcatheter mitral valve repair, left atrial appendix and atrial septal defect closures), assessment of the mitral valve in surgical repair, measurement of left ventricular outflow tract area for transcatheter valvular replacements, and estimating right and left ventricular volumes and function. The exact localization of paravalvular leakage is another strength of RT 3D TEE. The major limitation is the reduced temporal resolution compared to 2D TEE.

SUMMARY

Three-dimensional echocardiography is a powerful tool that improves communication and accurate measurements of cardiac structures.

Long-Term Results after Surgical Treatment of Ebstein's Anomaly: a 30-year Experience

BACKGROUND AND OBJECTIVES

The aim of the study is to evaluate the long-term results after a surgical repair of Ebstein's anomaly.

SUBJECTS AND METHODS

Forty-eight patients with Ebstein's anomaly who underwent open heart surgery between 1982 and 2013 were included. Median age at operation was 5.6 years (1 day-42.1 years). Forty-five patients (93.7%) demonstrated tricuspid valve (TV) regurgitation of less than moderate degree. When the patients were divided according to Carpentier's classification, types A, B, C, and D were 11, 21, 12, and 4 patients, respectively. Regarding the type of surgical treatment, bi-ventricular repair (n=38), one-and-a half ventricular repair (n=5), and single ventricle palliation (n=5) were performed. Of 38 patients who underwent a bi-ventricular repair, TV repairs were performed by Danielson's technique (n=20), Carpentier's technique (n=11), Cone repair (n=4), and TV annuloplasty (n=1). Two patients underwent TV replacement. Surgical treatment strategies were different according to Carpentier's types (p<0.001) and patient's age (p=0.022).

RESULTS

There were 2 in-hospital mortalities (4.2%; 1 neonate and 1 infant) and 2 late mortalities during follow-up. Freedom from recurrent TV regurgitation rates at 5, 10, and 15 years were 88.6%, 66.3%, 52.7%, respectively. TV regurgitation recurrence did not differ according to surgical method (p=0.800). Survival rates at 5, 10, and 20 years were 95.8%, 95.8%, and 85.6%, respectively, and freedom from reoperation rates at 5, 10, and 15 years were 85.9%, 68.0%, and 55.8%, respectively.

CONCLUSION

Surgical treatment strategies were decided according to Carpentier's type and patient's age. Overall survival and freedom from reoperation rates at 10 years were 95.8% and 68.0%, respectively. Approximately 25% of patients required a second operation for TV during the follow-up.