Pathophysiology of Tricuspid Regurgitation: Quantitative Doppler Echocardiographic Assessment of Respiratory Dependence

Unenhanced computed tomography as a diagnostic tool in suspected pulmonary hypertension: a retrospective cross-sectional pilot study

Background

Computed tomography pulmonary angiography (CTPA) has been proposed to be diagnostic for pulmonary hypertension (PH) in multiple studies. However, the utility of the unenhanced CT measurements diagnosing PH has not been fully assessed. This study aimed to assess the diagnostic utility and reproducibility of cardiac and great vessel parameters on unenhanced computed tomography (CT) in suspected pulmonary hypertension (PH).

Methods

In total, 42 patients with suspected PH who underwent unenhanced CT thorax and right heart catheterization (RHC) were included in the study. Three observers (a consultant radiologist, a specialist registrar in radiology, and a medical student) measured the parameters by using unenhanced CT. Diagnostic accuracy of the parameters was assessed by area under the receiver operating characteristic curve (AUC). Inter-observer variability between the consultant radiologist (primary observer) and the two secondary observers was determined by intra-class correlation analysis (ICC).

Results

Overall, 35 patients were diagnosed with PH by RHC while 7 patients were not. Main pulmonary arterial (MPA) diameter was the strongest (AUC 0.79 to 0.87) and the most reproducible great vessel parameter. ICC comparing the MPA diameter measurement of the consultant radiologist to the specialist registrar's and the medical student's were 0.96 and 0.92, respectively. Right atrial area was the cardiac measurement with highest accuracy and reproducibility (AUC 0.76 to 0.79; ICC 0.980, 0.950) followed by tricuspid annulus diameter (AUC 0.76 to 0.79; ICC 0.790, 0.800).

Conclusions

MPA diameter and right atrial areas showed high reproducibility. Diagnostic accuracies of these were within the range of acceptable to excellent, and might have clinical value. Tricuspid annular diameter was less reliable and less diagnostic and was therefore not a recommended diagnostic measurement.

Annular remodelling predicts outcome in isolated severe tricuspid regurgitation: a registry-based echocardiographic analysis

AIMS

Depending on volume status, secondary tricuspid regurgitation (sTR) has a strong dynamic component. In contrast, associated structural dilatation of the tricuspid annulus and the right heart chambers may be less volume dependent. This study aimed to assess the prognostic value of right heart remodelling in isolated severe sTR (isoTR).

METHODS AND RESULTS

A total of 36 000 patients from the longitudinal echocardiographic database of our tertiary centre were screened for severe isoTR [vena contracta (VC) ≥ 7 mm] in the absence of atrial fibrillation (AF), other valve disease, and/or reduced systolic left ventricular function. Echocardiographic examinations were re-read, focusing on right ventricular (RV) parameters and on quantitative and qualitative parameters of isoTR. All-cause mortality was defined as the primary endpoint. Two hundred and sixteen patients fulfilled the inclusion criteria. Severe TR was predominant; only few were classified in the new grades massive [n = 23 (10%)] and torrential TR [n = 4 (2%)]. During a median follow-up of 35 months (20-53), all-cause mortality was 31% (n = 67). Multivariate Cox regression analysis revealed no association of VC, effective regurgitant orifice area, or regurgitant volume with all-cause mortality. However, indexed RV end-diastolic diameter (P < 0.001), indexed right atrial dimensions (P = 0.019), and particularly tricuspid valve (TV) annulus diameter diastole index (P = 0.002) and TV annulus diameter systole index (P = 0.001) were significantly associated with outcome.

CONCLUSION

Severe isolated TR in the absence of AF is a rare finding with a grim prognosis. Tricuspid annular diameter dimensions rather than quantitative measures of TR proved to be of significant prognostic value indicating a continuous remodelling leading to a 'point of no return' with a dismal outcome.

Tricuspid Regurgitation: From Imaging to Clinical Trials to Resolving the Unmet Need for Treatment

Tricuspid regurgitation (TR) is a highly prevalent and heterogeneous valvular disease, independently associated with excess mortality and high morbidity in all clinical contexts. TR is profoundly undertreated by surgery and is often discovered late in patients presenting with right-sided heart failure. To address the issue of undertreatment and poor clinical outcomes without intervention, numerous structural tricuspid interventional devices have been and are in development, a challenging process due to the unique anatomic and physiological characteristics of the tricuspid valve, and warranting well-designed clinical trials. The path from routine practice TR detection to appropriate TR evaluation, to conduction of clinical trials, to enriched therapeutic possibilities for improving TR access to treatment and outcomes in routine practice is complex. Therefore, this paper summarizes the key points and methods crucial to TR detection, quantitation, categorization, risk-scoring, intervention-monitoring, and outcomes evaluation, particularly of right-sided function, and to clinical trial development and conduct, for both interventional and surgical groups.

Tricuspid repair in mitral regurgitation surgery: a systematic review and meta-analysis

BACKGROUND

Concomitant tricuspid repair in MR surgery is indicated in patients with severa tricuspid regurgitation, however, concomitant repair in less-than-severe TR patients is still a matter of debate.

METHODS

In December 2021, we systematically searched PubMed, Embase and Cochrane databases for randomised control trials (RCTs) comparing isolated MR surgery versus MR surgery with concomitant TR annuloplasty. Four studies were included, resulting in 651 patients (323 in the prophylactic tricuspid intervention group and 328 in the no tricuspid intervention group).

RESULTS

Our meta-analysis showed a similar all-cause mortality and perioperative mortality for concomitant prophylactic tricuspid repair when compared with no tricuspid intervention (pooled odds ratio (OR), 0.54; 95% confidence interval (CI): 0.25-1.15, P = 0.11; I² = 0% and pooled OR, 0.54; 95% CI: 0.25-1.15, P = 0.11; I² = 0%, respectively) in patients undergoing MV surgery. despite a significantly lower TR progression (pooled OR, 0.06; 95% CI: 0.02-0.24, P < 0.01; I² = 0%). Additionally, similar New York Heart Association (NYHA) classes III and IV were identified in both concomitant prophylactic tricuspid repair and no tricuspid intervention, despite a lower trend in the tricuspid intervention group (pooled OR, 0.63; 95% CI: 0.38-1.06, P = 0.08; I² = 0%).

CONCLUSIONS

Our pooled analyses suggested that TV repair at the time of MV surgery in patients with moderate or less-than-moderate TR did not impact on perioperative or postoperative all-cause mortality, despite reducing TR severity and TR progression following the intervention.

Comparison of effective regurgitant orifice area by the PISA method and tricuspid coaptation gap measurement to identify very severe tricuspid regurgitation and stratify mortality risk

Introduction

Various definitions of very severe (VS) tricuspid regurgitation (TR) have been proposed based on the effective regurgitant orifice area (EROA) or tricuspid coaptation gap (TCG). Because of the inherent limitations associated with the EROA, we hypothesized that the TCG would be more suitable for defining VSTR and predicting outcomes.

Materials and methods

In this French multicentre retrospective study, we included 606 patients with ≥moderate-to-severe isolated functional TR (without structural valve disease or an overt cardiac cause) according to the recommendations of the European Association of Cardiovascular Imaging. Patients were further stratified into VSTR according to the EROA (≥60 mm²) and then according to the TCG (≥10 mm). The primary endpoint was all-cause mortality and the secondary endpoint was cardiovascular mortality.

Results

The relationship between the EROA and TCG was poor (R²=0.22), especially when the size of the defect was large. Four-year survival was comparable between patients with an EROA <60 mm² vs. ≥60 mm² (68 ± 3% vs. 64 ± 5%, p = 0.89). A TCG ≥10 mm was associated with lower four-year survival than a TCG <10 mm (53 ± 7% vs. 69 ± 3%, p < 0.001). After adjustment for covariates, including comorbidity, symptoms, dose of diuretics, and right ventricular dilatation and dysfunction, a TCG ≥10 mm remained independently associated with higher all-cause mortality (adjusted HR[95% CI] = 1.47[1.13-2.21], p = 0.019) and cardiovascular mortality (adjusted HR[95% CI] = 2.12[1.33-3.25], p = 0.001), whereas an EROA ≥60 mm² was not associated with all-cause or cardiovascular mortality (adjusted HR[95% CI]: 1.16[0.81-1.64], p = 0.416, and adjusted HR[95% CI]: 1.07[0.68-1.68], p = 0.784, respectively).

Conclusion

The correlation between the TCG and EROA is weak and decreases with increasing defect size. A TCG ≥10 mm is associated with increased all-cause and cardiovascular mortality and should be used to define VSTR in isolated significant functional TR.

Multicentric randomized evaluation of a tricuspid valve percutaneous repair system (clip for the tricuspid valve) in the treatment of severe secondary tricuspid regurgitation Tri.Fr Design paper

AIMS

Tricuspid regurgitation (TR) is associated with significant morbidity and mortality. Its independent prognostic role has been repeatedly demonstrated. However, this valvular heart condition is largely undertreated because of the increased risk of surgical repair. Recently, transcatheter techniques for the treatment of TR have emerged, but their implications for the clinical endpoints are still unknown.

METHODS AND RESULTS

The Tri.fr trial will be a multicentre, controlled, randomized (1:1 ratio), superior, open-label, and parallel-group study conducted in 300 patients with severe secondary TR that is considered non-surgical by heart teams. Inclusion will be possible only after core laboratory review of transthoracic and transoesophageal echocardiography and after validation by the clinical eligibility committee. A description of the mechanisms of the TR will be conducted by the core laboratory. Atrial or ventricular impacts on the severity of the secondary TR will be taken into account for the randomization. The patients will be followed for 12-month, and the primary outcome will be the Packer composite clinical endpoint [combining New York Heart Association class, patient global assessment (PGA), and major cardiovascular events]. It will test the hypothesis that a tricuspid valve percutaneous repair strategy using a clip dedicated to the tricuspid valve is superior to best guideline-directed medical therapy in symptomatic patients with severe secondary TR.

CONCLUSION

Tri.fr will be the first randomized, academic, multicentre study testing the value of percutaneous correction in patients with severe secondary TR.

Unenhanced computed tomography as a diagnostic tool in suspected pulmonary hypertension: a retrospective cross-sectional pilot study

Background: Computed tomography pulmonary angiography (CTPA) has been proposed to be diagnostic for pulmonary hypertension (PH) in multiple studies. However, the utility of the unenhanced CT measurements diagnosing PH has not been fully assessed.  This study aimed to assess the diagnostic utility and reproducibility of cardiac and great vessel parameters on unenhanced computed tomography (CT) in suspected pulmonary hypertension (PH). Methods: In total, 42 patients with suspected PH who underwent unenhanced CT thorax and right heart catheterization (RHC) were included in the study. Three observers (a consultant radiologist, a specialist registrar in radiology, and a medical student) measured the parameters by using unenhanced CT. Diagnostic accuracy of the parameters was assessed by area under the receiver operating characteristic curve (AUC). Inter-observer variability between the consultant radiologist (primary observer) and the two secondary observers was determined by intra-class correlation analysis (ICC). Results: Overall, 35 patients were diagnosed with PH by RHC while 7 patients were not. Main pulmonary arterial (MPA) diameter was the strongest (AUC 0.79 to 0.87) and the most reproducible great vessel parameter. ICC comparing the MPA diameter measurement of the consultant radiologist to the specialist registrar’s and the medical student’s were 0.96 and 0.92, respectively. Right atrial area was the cardiac measurement with highest accuracy and reproducibility (AUC 0.76 to 0.79; ICC 0.980, 0.950) followed by tricuspid annulus diameter (AUC 0.76 to 0.79; ICC 0.790, 0.800). Conclusions: MPA diameter and right atrial areas showed high reproducibility. Diagnostic accuracies of these were within the range of acceptable to excellent, and might have clinical value. Tricuspid annular diameter was less reliable and less diagnostic and was therefore not a recommended diagnostic measurement.

Outcome of consistent guideline-based tricuspid management in patients undergoing degenerative mitral regurgitation correction

Objectives

Despite coherent guidelines, management of functional tricuspid regurgitation (FTR) consequences on outcome in the context of degenerative mitral regurgitation (DMR) remains controversial due to lacking series of large magnitude with rigorous application of tricuspid guidelines and strict long-term echocardiographic follow-up. Thus, we aimed at gathering such a cohort to examine outcomes of patients undergoing DMR surgery following tricuspid surgery guidelines.

Methods

All consecutive patients with isolated DMR 2005-2015 operated on with baseline FTR assessment and tricuspid annulus diameter measurement were identified. Operative complications, postoperative tricuspid regurgitation incidence, and survival were assessed overall and stratified by guideline-based tricuspid annuloplasty (TA) indication (severe FTR or tricuspid annulus diameter ≥40 mm).

Results

Among 441 patients with DMR undergoing mitral repair (66 ± 13 years, 30% female, ejection fraction 66 ± 10%, systolic pulmonary artery pressures 39 ± 12 mm Hg) followed 6 [3-9] years, patients with TA (n = 234, 53%) had generally similar presentation versus without TA (n = 207, 47%; all P ≥ .2) except for more atrial fibrillation and larger left ventricle (both P ≥ .0003). Patients with TA showed longer bypass time, more maze procedures (all P ≤ .001), but hospital stay, renal-failure, pacemaker implantation, and operative mortality (overall 0.9%) were comparable (all P ≥ .2). Postoperative incidence of moderate/severe FTR (0% at 1 year) became over time greater among patients without TA (5-year 8% [4%-13%] vs 3% [1%-11%] and 10-year 10% [6%-16%] vs 4% [1%-16%], P = .01). Survival (95% confidence interval) throughout follow-up was 85% (77%-89%) at 10 years, with hazard ratio 0.57 (0.29-1.10), P = .09. for patients with TA versus without.

Conclusions

In this large surgical DMR cohort, guideline-based FTR management was safe and effective. While long-term mortality did not reach significance, postoperative incidence of moderate/severe FTR, overall low, was nevertheless greater in patients who did not appear to require TA at surgery and linked to tricuspid annular dimension. Thus, future multicenter prospective cohorts with long-term follow-up are warranted to re-examine thresholds for TA performance and impact on survival.

Progression of Tricuspid Regurgitation After Surgery for Ischemic Mitral Regurgitation

BACKGROUND

Whether to repair nonsevere tricuspid regurgitation (TR) during surgery for ischemic mitral valve regurgitation (IMR) remains uncertain.

OBJECTIVES

The goal of this study was to investigate the incidence, predictors, and clinical significance of TR progression and presence of ≥moderate TR after IMR surgery.

METHODS

Patients (n = 492) with untreated nonsevere TR within 2 prospectively randomized IMR trials were included. Key outcomes were TR progression (either progression by ≥2 grades, surgery for TR, or severe TR at 2 years) and presence of ≥moderate TR at 2 years.

RESULTS

Patients' mean age was 66 ± 10 years (67% male), and TR distribution was 60% ≤trace, 31% mild, and 9% moderate. Among 2-year survivors, TR progression occurred in 20 (6%) of 325 patients. Baseline tricuspid annular diameter (TAD) was not predictive of TR progression. At 2 years, 37 (11%) of 323 patients had ≥moderate TR. Baseline TR grade, indexed TAD, and surgical ablation for atrial fibrillation were independent predictors of ≥moderate TR. However, TAD alone had poor discrimination (area under the curve, ≤0.65). Presence of ≥moderate TR at 2 years was higher in patients with MR recurrence (20% vs. 9%; p = 0.02) and a permanent pacemaker/defibrillator (19% vs. 9%; p = 0.01). Clinical event rates (composite of ≥1 New York Heart Association functional class increase, heart failure hospitalization, mitral valve surgery, and stroke) were higher in patients with TR progression (55% vs. 23%; p = 0.003) and ≥moderate TR at 2 years (38% vs. 22%; p = 0.04).

CONCLUSIONS

After IMR surgery, progression of unrepaired nonsevere TR is uncommon. Baseline TAD is not predictive of TR progression and is poorly discriminative of ≥moderate TR at 2 years. TR progression and presence of ≥moderate TR are associated with clinical events. (Comparing the Effectiveness of a Mitral Valve Repair Procedure in Combination With Coronary Artery Bypass Grafting [CABG] Versus CABG Alone in People With Moderate Ischemic Mitral Regurgitation, NCT00806988; Comparing the Effectiveness of Repairing Versus Replacing the Heart's Mitral Valve in People With Severe Chronic Ischemic Mitral Regurgitation, NCT00807040).

Correlation Between Doppler Echocardiography and Right Heart Catheterisation-Derived Systolic and Mean Pulmonary Artery Pressures: Determinants of Discrepancies Between the Two Methods

BACKGROUND

There is still controversy about whether transthoracic echocardiography (TTE) can provide reliable estimations of pulmonary artery pressures (PAP). The primary endpoint of this study was to evaluate the correlation between TTE and right heart catheterisation (RHC) in estimating systolic (SPAP) and mean (MPAP) pulmonary artery pressures.

METHODS

Between January 2011 and December 2018, 141 consecutive patients (average age 63.6±11.5 years; 84 women) with suspected or confirmed pulmonary hypertension (PH) were enrolled into this retrospective observational monocentric study. All patients underwent TTE and, within 3 hours, RHC. The correlation between TTE and RHC in estimating both SPAP and MPAP was retrospectively determined.

RESULTS

Seventeen (17) of the patients were excluded due to insufficient TTE signal quality. Of the remaining 124 patients, 18 had no PH. There was moderate correlation between both SPAP and MPAP estimated by TTE and those assessed by RHC (r=0.65 and r=0.60, respectively). Bland-Altman analysis revealed a bias of -11.9 mmHg (with the 95% limits of agreement ranging -45.4 to +21.5 mmHg) for SPAP estimation and -4.6 mmHg (with the 95% limits of agreement ranging -27.9 to +18.8 mmHg) for MPAP estimation, suggesting a general overestimation of PAP by TTE. The main factors responsible for discrepancies between TTE and RHC were: female gender, arrhythmic cardiac electrical activity, systemic arterial hypertension, and diuretic treatment.

CONCLUSIONS

Transthoracic echocardiography frequently overestimated PAP in comparison with RHC, especially in hypertensive women with arrhythmias and under diuretic treatment.

Sources of Variability in Vena Contracta Area Measurement for Tricuspid Regurgitation Severity Grading: Comparison of Technical Settings and Vendors

BACKGROUND

Previous studies found different cutoffs of vena contracta area (VCA) to define severe tricuspid regurgitation (TR). The aim of this study was to investigate the factors associated with such variability by comparing technical variables and vendors.

METHODS

Sixty-nine patients with scheduled tricuspid surgery were included in this prospective study. For each patient, TR data sets were obtained on three-dimensional color Doppler transthoracic echocardiography on at least two of three systems: GE Vivid E95 (n = 39), Siemens SC2000 Prime (n = 64), and Philips EPIQ 7C (n = 60). VCA was measured using default settings or with color baseline shifted on all three platforms and with minimal color gain (10%-20%) on the GE platform.

RESULTS

Color gain reduction and baseline shift caused significant change sin VCA measurement (-46% and 10%, respectively). Intervendor comparison exhibited wide limits of agreement (narrowest range, -74% to 167%), with either default or optimized settings. Different technical settings, platforms, and reference methods all produced different VCA cutoffs for severe TR.

CONCLUSIONS

VCA measurement in TR is sensitive to technical factors and demonstrates intervendor variability. Technical variables in VCA measurement should be reported in detail to allow comparison among research studies. The same vendor and settings should be used for longitudinal analysis of TR VCA in the same patient in multivendor echocardiography laboratories.

Three-dimensional transthoracic echocardiographic evaluation of tricuspid regurgitation severity using proximal isovelocity surface area: comparison with volumetric method

BACKGROUND

The quantification of tricuspid regurgitation(TR) using three-dimensional(3D) proximal isovelocity surface area (PISA) derived effective regurgitant orifice area (EROA) is feasible in functional TR. The aim of our study was to explore the diagnostic accuracy and utility of 3D PISA EROA in a larger population of different etiologies.

METHODS

One hundred and seven patients with confirmed TR underwent 2D and 3D transthoracic echocardiography (TTE). 3D PISA EROA was calculated and EROA derived from 3D regurgitant volume (Rvol) was used as the reference.

RESULTS

3D PISA EROA showed better correlation in primary TR than in functional TR(r = 0.897, P < 0.01). 3D PISA EROA differentiated severe TR with comparable accuracy in patients with primary and functional etiology (Z-value 16.506 vs 21.202), but with different cut-offs (0.49cm² vs. 0.41 cm²). The chi-square value for incorporated clinical symptoms, positive echocardiographic results and 3D PISA EROA to grade severe TR was higher than only included clinical symptoms or incorporated clinical symptoms and positive echocardiographic results (chi-square value 137.233, P < 0.01).

CONCLUSION

TR quantification using 3D PISA EROA is feasible and accurate under different etiologies. It has incremental diagnostic value for evaluating severe TR.

Imaging and Patient Selection for Transcatheter Tricuspid Valve Interventions

With the emergence of transcatheter solutions for the treatment of tricuspid regurgitation (TR) increased attention has been directed to the once neglected tricuspid valve (TV) complex. Recent studies have highlighted new aspects of valve anatomy and TR etiology. The assessment of valve morphology along with quantification of regurgitation severity and RV function pose several challenges to cardiac imagers guiding transcatheter valve procedures. This review article aims to give an overview over the role of modern imaging modalities during assessment and treatment of the TV.

Developments in transcatheter tricuspid valve therapies

Introduction: Transcatheter tricuspid valve (TV) procedures emerged as an alternative to surgery for symptomatic high-risk patients with severe tricuspid regurgitation.Areas covered: A literature search was performed using PubMed. Authors review clinical evidence in this field, the imaging features and the developments in TV transcatheter technologies. Currently, transcatheter devices for TV procedures can be allocated into four main groups: 1) those ones targeting leaflet malcoaptation, 2) those addressing annular dilatation, 3) those performing heterotopic valve implantation and 4) those onesaccomplishing a complete transcatheter replacement of the valve.Expert opinion: Actually, encouraging results are provided by initial experience in the field of transcatheter TV procedures. However, this field remains full of challenges that faced could lead to better results and prognosis for the patients. The next steps in this emerging field will need to focus on accurate patient selection, an early patient referral and on studies comparable and providing long-term data.

3-Dimensional Echocardiography: Latest Developments and Future Directions

The ongoing refinements in 3-dimensional (3D) echocardiography technology continue to expand the scope of this imaging modality in clinical cardiology by offering new features that stem from the ability to image the heart in its complete dimensionality. Over the years, countless publications have described these benefits and tested new frontiers where 3D echocardiographic imaging seemed to offer promising ways to improve patients' care. These include improved techniques for chamber quantification and novel ways to visualize cardiac valves, including 3D printing, virtual reality, and holography. The aims of this review article are to focus on the most important developments in the field in the recent years, discuss the current utility of 3D echocardiography, and highlight several interesting future directions.

Characteristics and treatment strategies for severe tricuspid regurgitation

OBJECTIVE

This study aimed to identify characteristics, spectrum of tricuspid regurgitation (TR) severity and treatment patterns in patients considered for intervention of severe TR at a tertiary centre. The population being considered for TR intervention is currently not well defined and the role of transcatheter interventions is unclear.

METHODS

The study involved 87 patients with severe TR considered for intervention from 1 March 2016 to 12 November 2018 at Mayo Clinic. Patients receiving medications alone were compared with those receiving intervention to identify patterns in demographics, clinical/echocardiographic associations and survival.

RESULTS

Mean age was 80±9 (56% female), 93% had atrial fibrillation and 64% had chronic kidney disease ≥3 a. Follow-up was 331±276 days; 95% were symptomatic with 6 min walk distance of 270±110 m. Loop diuretics were used in 93%; aldosterone antagonists in 35%. Mean tricuspid annular plane systolic excursion was 15.6±3.8 mm, effective regurgitant orifice area (EROA) 82±32 mm² and stroke volume index 39±11 mL/m²; 48% had at least moderate right ventricular (RV) dysfunction, and 75% did not undergo intervention. Patients receiving intervention showed trends towards larger EROA (93±33 vs 75±31 mm²), better right ventricular function and more severe symptoms. Overall group 30-day and 1-year survival were 100% and 76%, respectively.

CONCLUSIONS

Patients with severe TR considered for intervention are commonly elderly with atrial fibrillation, advanced TR and RV dysfunction; 75% were treated with medications alone and not offered intervention. Patients with greater EROA, better RV function and more severe symptoms were more likely to receive intervention. These findings have implications for future trial design.

Large animal model of acute right ventricular failure with functional tricuspid regurgitation

BACKGROUND

Functional tricuspid regurgitation (FTR) commonly arises secondary to conditions affecting the left heart and is associated with right ventricular dysfunction and tricuspid annular dilatation. We set out to establish an animal model of acute RV failure (RVF) with FTR resembling the clinical features.

METHODS

Ten adult sheep had pressure sensors placed in the LV, RV, and right atrium while sonomicrometry crystals were implanted around tricuspid annulus and on the RV. Animals were studied open-chest to assess for RV function and FTR after: (1) volume infusion, (2) pulmonary artery constriction, (3) 5 min posterior descending artery occlusion, and (4) combination of all interventions. Hemodynamic, echocardiographic, and sonomicrometry data were collected at baseline and after every intervention. RV dimensions, RV strain, and annular area, perimeter, and size were calculated from crystal coordinates. The model was validated in six additional sheep studied only before and after combined interventions.

RESULTS

Neither volume infusion, pulmonary hypertension, nor ischemia were associated with RVF or clinically significant TR when applied separately but combined resulted in RVF and greater than moderate FTR. In the validation group, maximal RV volume increased (62 ± 14 vs 70 ± 16 ml, p = 0.006), contractility decreased (20 ± 6 vs 12 ± 2%, p = 0.02), and strain increased. FTR increased from 0.4 ± 0.5 to 2.5 ± 0.8 (p < 0.001) and annular area from 652 ± 87 mm² to 739 ± 87 mm² (p = 0.005).

CONCLUSIONS

The developed ovine model of acute RVF was associated with significant annular and RV enlargement and FTR. This novel and clinically pertinent research platform offers insight into the acute RVF pathophysiology and can be utilized to evaluate treatment interventions.

Doppler-Echocardiographic Assessment of Tricuspid Regurgitation

Compared with the vast literature concerning the echocardiographic assessment of mitral, or aortic disease, the data concerning the evaluation of tricuspid regurgitation (TR) is very limited. In this review we summarized the present data concerning the assessment of TR. We review the present knowledge concerning the pathogenesis of TR showing that it is extremely multi-factorial, thus, when assessing patients with TR by echocardiography it is imperative to focus on four major aspects: evaluation of severity of TR, assessment of the etiology of TR, evaluation of the mechanism of TR and suitability for surgical or per-cutaneous repair.

Pulmonary vascular resistance versus pulmonary artery pressure for predicting right ventricular remodeling and functional tricuspid regurgitation

BACKGROUND

Pulmonary hypertension (PH) is a common cause of right ventricular (RV) remodeling and functional tricuspid regurgitation (FTR), but incremental pulmonary artery systolic pressure (PASP) does not always correlate with anatomic and functional RV changes. This study aimed to evaluate a noninvasive measure of pulmonary vascular resistance (PVR) for predicting RV dilatation, RV dysfunction, and severity of FTR.

METHODS

We prospectively analyzed consecutive stable patients with PASP ≥ 35 mm Hg or any degree of RV dilatation or dysfunction secondary to PH. Noninvasive PVR was calculated based on FTR peak velocity and flow in RV outflow tract.

RESULTS

We included 251 patients, aged 72.1 ± 11.4 years, 53% women, 74.9% with type 2 pulmonary hypertension. The mean PASP was 48.3 ± 12.2 mm Hg. Both PASP and PVR significantly correlated with FTR, RV dilatation, and RV systolic dysfunction. After dichotomizing FTR and RV dilatation and systolic dysfunction as nonsignificant vs significant, FTR and RV dilatation were similarly predicted by PASP and PVR, but RV dysfunction was better predicted by PVR (AUC = 0.78 [0.72-0.84] vs 0.66 [0.60-0.73] for PASP, P < 0.001). Patients with low PASP but high PVR showed worse RV and left ventricular function but lower rates of right heart failure and smaller inferior vena cava, compared to patients with high PASP but low PVR.

CONCLUSIONS

Noninvasive PVR was superior to PASP for predicting RV systolic dysfunction, but both were similarly associated with RV dilatation or FTR grade. PASP and PVR complement each other to define the echocardiographic findings and clinical status of the patient.

Tricuspid regurgitation diagnosis and treatment

Tricuspid regurgitation (TR) is the most common lesion of the tricuspid valve (TV). Mild TR is common and usually is benign. However, moderate or severe TR can lead to irreversible myocardial damage and adverse outcomes. Despite these findings, few patients with significant TR undergo surgery. The treatment of functional (secondary) TR in particular remains controversial because of high rates of residual or recurrent TR and poor outcomes following surgical intervention. Traditional teaching that functional TR resolves on its own if the underlying disease is successfully treated has proven to be incorrect. This review aims to clarify management of TR by describing the anatomy, pathophysiology, diagnosis, and treatment of TR, including the eventual possibility of percutaneous TV therapy.

Anatomy of the Tricuspid Valve, Pathophysiology of Functional Tricuspid Regurgitation, and Implications for Percutaneous Therapies

The tricuspid valve is a complex dynamic apparatus made up of many different closely linked structures: the annulus, the three leaflets, the chordae, the papillary muscles and the right ventricle. Other nearby structures, such as the coronary sinus ostium, the conduction system, the membranous septum, and the right coronary artery must be taken into account when dealing with the tricuspid. Annulus dilation and leaflet tethering due to right ventricular remodeling are the 2 major mechanisms responsible for most tricuspid regurgitation cases. Precise knowledge of tricuspid anatomy and function, as well as careful preoperative planning, is fundamental for successful transcatheter tricuspid procedures.

Evaluation of the hemodynamics and right ventricular function in pulmonary hypertension by echocardiography compared with right-sided heart catheterization

The present study aimed to evaluate hemodynamics and right ventricular function in patients with pulmonary hypertension (PH) using transthoracic echocardiography and to compare these results with measurements obtained using right-sided heart catheterization (RHC). A total of 75 patients with PH were examined using echocardiography and RHC. Patients were divided into the following two groups according to their difference between SPAP_echo and SPAP_RHC measurement: The overestimated group and underestimated group. The overestimated group included the subgroups group_over-A (difference <20 mmHg) and group_over-B (difference ≥20 mmHg), and the underestimated group included group_under-A (absolute value of the difference <20 mmHg) and group_under-B (absolute value of the difference ≥20 mmHg). SPAP_echo measurements were revealed to be significantly positively correlated with SPAP_RHC measurements (r=0.794; P<0.01). Among all echocardiographic measurements, only tricuspid annular plane systolic excursion (TAPSE) was significantly different between groups; it was increased in group_over-A and group_under-A compared with group_over-B (P<0.01). Although SPAP measurements obtained using echocardiography were significantly positively correlated with those obtained using RHC, a high proportion of overestimation or underestimation of SPAP by echocardiography remained.

Frequency and Associated Clinical Features of Functional Tricuspid Regurgitation in Patients With Chronic Atrial Fibrillation

Significant functional tricuspid regurgitation (TR) can develop in some but not all patients with chronic atrial fibrillation (AF). This study sought to identify factors likely to be involved in determining the severity of TR in patients with chronic AF. In this retrospective cohort study of adult patients referred for transthoracic echocardiography for evaluation of AF between 2004 and 2015, we identified 170 patients with chronic AF in the absence of structural or known coronary heart disease. Patients were classified into nonsevere (89 patients) versus severe TR (81 patients) groups based on a comprehensive assessment of color Doppler, spectral Doppler, and morphologic parameters of the tricuspid valve and right side of the heart. Patients with severe TR were significantly older (76 ± 10 vs 70 ± 11, p <0.001), with smaller body surface area (1.7 ± 0.3 m² vs 1.9 ± 0.23 m², p = 0.001) and with female predominance (percentage of men 30% vs 57%, p <0.001). Although comorbidities, use of cardiovascular medications, and left-sided cardiac parameters were statistically indistinguishable between these 2 groups, right-sided cardiac dimensions, tricuspid valve tethering height, and tricuspid valve tethering area were significantly larger in the severe TR group. A comprehensive multivariate logistic regression model (model 1) identified the age, gender, right ventricular systolic pressure, right atrial volume index, and right ventricular end-diastolic area as independent factors associated with TR severity. A simplified logistic regression model using only clinical factors (model 2) confirmed the age, gender, and right ventricular systolic pressure as clinically relevant factors in relation to TR.

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

Current knowledge of functional tricuspid regurgitation (FTR) as a progressive entity, worsening the prognosis of patients irrespective of its aetiology, has led to renewed interest in the pathophysiology and assessment of FTR. For the proper management of FTR, not only its severity, but also the mechanisms, the mode of leaflet coaptation, the degree of tricuspid annulus enlargement and leaflet tenting, and the haemodynamic consequences for right atrial and right ventricular morphology and function have to be taken into account. A better assessment of the anatomy and function of tricuspid apparatus and tricuspid regurgitation severity should help with the appropriate selection of patients who will benefit from either surgical tricuspid valve repair/replacement or a percutaneous procedure, especially among patients who are to undergo or have undergone primary left-sided valvular surgery. In this article, we review the anatomy, pathophysiology and the use of imaging techniques to assess patients with FTR, as well as the various treatment options for FTR, including emerging transcatheter procedures. The limitations affecting the current approach to FTR patients and the unmet clinical needs for their management have also been discussed.

Leaflet area as a determinant of tricuspid regurgitation severity in patients with pulmonary hypertension

BACKGROUND

Tricuspid regurgitation (TR) is a risk factor for mortality in pulmonary hypertension (PH). TR severity varies among patients with comparable degrees of PH and right ventricular remodeling. The contribution of leaflet adaptation to the pathophysiology of TR has yet to be examined. We hypothesized that tricuspid leaflet area (TLA) is increased in PH, and that the adequacy of this increase relative to right ventricular remodeling determines TR severity.

METHODS AND RESULTS

A prospective cohort of 255 patients with PH from pre and postcapillary pathogeneses was assembled from 2 centers. Patients underwent a 3-dimensional echocardiogram focused on the tricuspid apparatus. TLA was measured with the Omni 4D software package. Compared with normal controls, patients with PH had a 2-fold increase in right ventricular volumes, 62% increase in annular area, and 49% increase in TLA. Those with severe TR demonstrated inadequate increase in TLA relative to the closure area, such that the ratio of TLA:closure area <1.78 was highly predictive of severe TR (odds ratio, 68.7; 95% confidence interval, 16.2-292.7). The median vena contracta width was 8.5 mm in the group with small TLA and large closure area as opposed to 4.8 mm in the group with large TLA and large closure area.

CONCLUSIONS

TLA plays a significant role in determining which patients with PH develop severe functional TR. The ratio of TLA:closure area, reflecting the balance between leaflet adaptation versus annular dilation and tethering forces, is an indicator of TR severity that may identify which patients stand to benefit from leaflet augmentation during tricuspid valve repair.

Leaflet Area as a Determinant of Tricuspid Regurgitation Severity in Patients With Pulmonary Hypertension

Background—

Tricuspid regurgitation (TR) is a risk factor for mortality in pulmonary hypertension (PH). TR severity varies among patients with comparable degrees of PH and right ventricular remodeling. The contribution of leaflet adaptation to the pathophysiology of TR has yet to be examined. We hypothesized that tricuspid leaflet area (TLA) is increased in PH, and that the adequacy of this increase relative to right ventricular remodeling determines TR severity.

Methods and Results—

A prospective cohort of 255 patients with PH from pre and postcapillary pathogeneses was assembled from 2 centers. Patients underwent a 3-dimensional echocardiogram focused on the tricuspid apparatus. TLA was measured with the Omni 4D software package. Compared with normal controls, patients with PH had a 2-fold increase in right ventricular volumes, 62% increase in annular area, and 49% increase in TLA. Those with severe TR demonstrated inadequate increase in TLA relative to the closure area, such that the ratio of TLA:closure area <1.78 was highly predictive of severe TR (odds ratio, 68.7; 95% confidence interval, 16.2–292.7). The median vena contracta width was 8.5 mm in the group with small TLA and large closure area as opposed to 4.8 mm in the group with large TLA and large closure area.

Conclusions—

TLA plays a significant role in determining which patients with PH develop severe functional TR. The ratio of TLA:closure area, reflecting the balance between leaflet adaptation versus annular dilation and tethering forces, is an indicator of TR severity that may identify which patients stand to benefit from leaflet augmentation during tricuspid valve repair.

Indications for Surgery for Tricuspid Regurgitation

Despite the fact that tricuspid regurgitation (TR) can result in significant symptoms, patients are rarely referred for isolated surgical repair, or replacement, and most surgeries are performed in the context of other planned cardiac surgery. In this article, we review the different causes of TR, the natural history of untreated severe TR, indications and timing for isolated TR surgery, indications for TR surgery performed at the time of left-sided valve surgery, and surgical approaches for correction of TR.

Right-sided valve disease

In this review, we discuss right-sided heart valve disease, namely tricuspid regurgitation (TR), tricuspid stenosis, pulmonary regurgitation, pulmonary stenosis and right-sided endocarditis. These are frequently seen in conjunction with other diseases, making assessment of their significance more difficult, but it has become increasingly clear that moderate or severe right-sided heart valve disease, in particular TR, is associated with worse prognosis. There remain large gaps in our knowledge of medical and interventional treatment, but in this article we outline what is known about the causes, presentation and management of these commonly seen conditions.

Effects of respiration on the velocity of tricuspid regurgitation and estimation of systolic pulmonary artery pressure in patients with right ventricle systolic dysfunction

OBJECTIVE

We investigated the effects of quiet respiration on the peak velocity of tricuspid regurgitation (TR) and estimation of systolic pulmonary artery pressure (SPAP) in patients with right ventricle (RV) systolic dysfunction using Doppler echocardiography.

METHODS

Continuous-wave Doppler spectra of TR were recorded in 32 patients with and 28 controls without RV systolic dysfunction. Electrocardiography and respiratory tracing were recorded simultaneously. Expiratory and inspiratory peak velocities of TR were acquired and averaged for five consecutive respiratory cycles. The SPAP during expiration and inspiration was calculated.

RESULTS

The velocity of TR and SPAP was not significantly different between expiration and inspiration in controls (2.77 ± 0.23 and 2.82 ± 0.26 m/s, P = 0.776; 35.94 ± 4.96 and 36.18 ± 5.12 mmHg, P = 0.747), whereas the velocity of TR and SPAP decreased significantly from expiration to inspiration in patients with RV systolic dysfunction (3.27 ± 0.35 and 2.59 ± 0.22 m/s, P < 0.001; 53.72 ± 7.39, 38.45 ± 5.63 mmHg, P < 0.001).

CONCLUSIONS

Quiet respiration has significant effects on the velocity of TR in patients with RV systolic dysfunction. This factor should be taken into account when using Doppler echocardiography to estimate these patients' SPAP, and the measurements should be performed in patients at the end of expiration.