Effective regurgitant orifice area in tricuspid regurgitation: clinical implementation and follow-up study

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.

Prevalence and Prognostic Importance of Massive Tricuspid Regurgitation in Patients Undergoing Tricuspid Annuloplasty With Concomitant Left-Sided Valve Surgery: A Study on Rheumatic Valvular Heart Disease

BACKGROUND

The presence of tricuspid regurgitation (TR) is very common in patients with concomitant left-sided valve disease. Recent studies have advocated an additional grading of massive TR that is beyond severe. The present study sought to characterize the spectrum of TR in patients undergoing tricuspid annuloplasty (TA) and to evaluate the prognostic value of TR severity for post-operative outcome following TA.

METHODS

A total of 176 patients who underwent TA with combined left-sided valve surgery, secondary to rheumatic valvular heart disease, were prospectively evaluated. The severity of TR was quantified by effective regurgitant orifice area (EROA) using the proximal isovelocity surface area method. Patients were categorized as having non-massive TR (EROA < 0.6 cm2) or massive TR (EROA ≥ 0.6 cm2). Adverse outcome was defined as all-cause mortality or heart failure requiring hospital admission following TA.

RESULTS

A total of 55 (31%) patients were considered to have massive TR. Patients with massive TR had a greater right ventricular dimension but a smaller left ventricular dimension compared with those with non-massive TR. After a median follow-up of 39 months, 35 adverse events occurred. Cox-regression analysis showed that both continuous EROA and dichotomized EROA (massive vs. non-massive TR) were independently associated with adverse events even after multivariable adjustment. Further, Harrell C index demonstrated that the addition of massive TR provided better discrimination ability of a prediction model to known prognosticators following TA.

CONCLUSIONS

Massive TR is common and up to 31% of study population had massive TR. Massive TR was associated with adverse outcome in patients undergoing TA. Classification of the severity of TR by quantitative measures and identification of massive TR in patients with concomitant left-sided valve disease are essential when considering the optimal timing of corrective surgery.

Prognostic validation of partition values for quantitative parameters to grade functional tricuspid regurgitation severity by conventional echocardiography

AIMS

Quantitative echocardiography parameters are seldom used to grade tricuspid regurgitation (TR) severity due to relative paucity of validation studies and lack of prognostic data. To assess the relationship between TR severity and the composite endpoint of death and hospitalization for congestive heart failure (CHF); and to identify the threshold values of vena contracta width (VCavg), effective regurgitant orifice area (EROA), regurgitant volume (RegVol), and regurgitant fraction (RegFr) to define low, intermediate, and high-risk TR based on patients' outcome data.

METHODS AND RESULTS

A cohort of 296 patients with at least mild TR underwent 2D, 3D, and Doppler echocardiography. We built statistical models (adjusted for age, NYHA class, left ventricular ejection fraction, and pulmonary artery systolic pressure) for VCavg, EROA, RegVol, and RegFr to study their relationships with the hazard of outcome. The tertiles of the derived hazard values defined the threshold values of the quantitative parameters for TR severity grading. During 47-month follow-up, 32 deaths and 72 CHF occurred. Event-free rate was 14%, 48%, and 93% in patients with severe, moderate, and mild TR, respectively. Severe TR was graded as VCavg > 6 mm, EROA > 0.30 cm2, RegVol > 30 mL, and RegF > 45%.

CONCLUSION

This outcome study demonstrates the prognostic value of quantitative parameters of TR severity and provides prognostically meaningful threshold values to grade TR severity in low, intermediate, and high risk.

Quantitative assessment of tricuspid regurgitation using right and left ventricular stroke volumes obtained from tomographic equilibrium radionuclide ventriculography

BACKGROUND

Quantitative assessment of valve regurgitation using volumetric method by comparing right and left ventricular stroke volumes is still under investigations.

AIMS

To investigate the accuracy of tomographic equilibrium radionuclide ventriculography (t-ERV) for the quantification of tricuspid regurgitation (TR).

METHODS AND RESULTS

Sixty-one patients (44 men; mean age 59 ± 12 years) who underwent both t-ERV and transthoracic echocardiography (TTE) studies within 2 weeks for right ventricular systolic function assessment were eligible for inclusion. A sub-group of 22 patients underwent both t-ERV and CMR. Patients with mitral/aortic regurgitation by TTE were excluded of the study. TR regurgitant volume (RVol) was calculated using the proximal isovelocity surface area (PISA) method from TTE and the volumetric method (right ventricular stroke volume minus left ventricular stroke volume) from t-ERV. There was a significant correlation between RVol as assess by ERV and by TTE (R = 0.95, P < 0.0001). Intraclass correlation coefficient between TTE and ERV for TR quantification was 0.95 (P < 0.0001). Among patients who underwent CMR, the correlation between RVol obtained by TTE and by t-ERV and CMR were R = 0.81 and R = 0.75, respectively (all P < 0.0001).

CONCLUSION

TR assessment using the t-ERV correlates well with PISA from TTE in patients referred for right ventricular systolic function assessment.

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.

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.

The tricuspid valve in review: anatomy, pathophysiology and echocardiographic assessment with focus on functional tricuspid regurgitation

The tricuspid valve (TV) is a complex anatomical structure that incorporates a saddle-shaped annulus, asymmetric leaflets, the subvalvular apparatus and the right ventricle and its loading conditions. In this paper, an appreciation of the normal anatomy and physiology of the TV is reviewed before discussing functional tricuspid regurgitation (TR), a disease that has garnered renewed interest due to increased awareness of adverse outcomes and novel transcatheter therapeutic options. Two and three-dimensional echocardiographic imaging of the TV using transthoracic and transesophageal windows are subsequently discussed. The future of cardiovascular medicine will have more to offer the “forgotten” right-sided chambers and valves, and this review aims to refresh knowledge and enthusiasm around the forgotten but crucially important TV.

Imaging Needs in Novel Transcatheter Tricuspid Valve Interventions

The advent of novel transcatheter therapies for severe tricuspid regurgitation (TR) has attracted much attention. Novel 3-dimensional imaging techniques have permitted analysis of the tricuspid valve (TV) anatomy from unparalleled views and better understanding of the underlying pathophysiology of TR. Grading TR and assessment of right ventricular function remain challenging, and although 2-dimensional echocardiography is the mainstay imaging technique to evaluate patients with severe TR the use of 3-dimensional echocardiography and cardiovascular magnetic resonance is increasing. The number of transcatheter interventions for TR is growing, and procedural success relies significantly on the pre-procedural evaluation of the anatomy of the TV, etiology and severity of TR, right ventricular size and function, and importantly, the anatomic relationships of the TV. The role of multimodality imaging in patient selection and procedural planning for transcatheter TV repair is reviewed.

Quantitative assessment of effective regurgitant orifice: impact on risk stratification, and cut-off for severe and torrential tricuspid regurgitation grade

Aims 

Asses the added value of quantitative evaluation of tricuspid regurgitation (TR), the proper cut-off value for severe TR and ‘torrential TR’ based on outcome data. The added value of quantitative evaluation of TR, and the cut-off values associated with increased mortality are unknown.

Methods and results

In patients with all-cause TR assessed both qualitatively and quantitatively by proximal iso-velocity surface area method, long-term and 1-year outcome analysis was conducted. Thresholds for excess mortality were assessed using spline curves, receiver-operating characteristic curves, and minimum P-value analysis. The study involved 676 patients with all-cause TR (age 73.9 ± 14 years, male 45%, ejection fraction 52.9 ± 14%). Effective regurgitant orifice (ERO) was strongly associated with decreased survival in unadjusted [hazard ratio (HR) 2.38 (1.79–3.01), P &lt; 0.0001 per 0.1 cm2 increment] and adjusted [2.6 (1.25–5.0), P = 0.01] analyses. Quantitative grading was superior to qualitative grading in prediction of outcome (P &lt; 0.01). The optimal cut-off value for the best separation in survival between groups of patients with severe vs. lesser degree of TR was 0.35 cm2 [P &lt; 0.0001, HR =2.0 (1.5–2.7)]. ERO negatively impacted survival, even when including only the subgroup of patients with severe TR [HR 1.5 (1.01–2.3); P = 0.04]. The optimal threshold corresponding for the best separation for survival between groups of patients with severe vs. ‘torrential’ TR was 0.7 cm2 [P = 0.005, HR =2.6 (1.2–5.1)].

Conclusion 

TR can be severe and even ‘torrential’ and is associated with excess mortality. Quantitative assessment of TR by ERO measurement is a powerful independent predictor of outcome, superior to standard qualitative assessment. The optimal cut-off above which mortality is increased is 0.35 cm2, similar albeit slightly lower than suggested in recent guidelines. Torrential TR &gt;0.7 cm2 is associated with poorer survival compared to patients with severe TR (ERO &gt; 0.4 cm2 and &lt;0.7 cm2).

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.

State-of-the-Art Review of Echocardiographic Imaging in the Evaluation and Treatment of Functional Tricuspid Regurgitation

Functional or secondary tricuspid regurgitation (TR) is the most common cause of severe TR in the Western world. The presence of functional TR, either isolated or in combination with left heart disease, is associated with unfavorable natural history. Surgical mortality for isolated tricuspid valve interventions remains higher than for any other single valve surgery, and surgical options for repair do not have consistent long-term durability. In addition, as more patients undergo transcatheter left valve interventions, developing transcatheter solutions for functional TR has gained greater momentum. Numerous transcatheter devices are currently in early clinical trials. All patients require an assessment of valve morphology and function, and transcatheter devices typically require intraprocedural guidance by echocardiography. The following review will describe tricuspid anatomy, define echocardiographic views for evaluating tricuspid valve morphology and function, and discuss imaging requirements for the current transcatheter devices under development for the treatment of functional TR.

Relation of Tricuspid Regurgitation to Liver Stiffness Measured by Transient Elastography in Patients With Left-Sided Cardiac Valve Disease

The aim of the study was to evaluate the relation between tricuspid regurgitation (TR) severity and liver stiffness (LS) in patients with TR. A total of 131 patients with various degrees of TR secondary to left-sided heart valve disease were enrolled. Severity of TR was quantitatively assessed by proximal isovelocity surface area-derived effective regurgitant orifice (ERO). Patients were divided into 2 groups: 48 with mild-moderate TR (ERO <0.4 cm(2)) and 83 with severe TR (ERO ≥0.4 cm(2)). Transient elastography was used to measure the level of LS, an established marker of liver fibrosis, with the threshold of significant LS set at ≥12.5 kPa. Patients with severe TR had a higher LS and prevalence of significant LS than those with mild-moderate TR. Furthermore, LS and significant LS independently correlated with TR-ERO, right atrial pressure and inferior vena cava (IVC) diameter. The presence of a large TR-ERO (≥0.4 cm(2)) and IVC diameter (>2.15 cm(2)) provided a high specificity of 78% for significant LS. In conclusion, the present study demonstrates that TR-ERO, right atrial pressure, and IVC diameter are important parameters associated with LS in patients with TR.

Proximal isovelocity surface area by single-beat three-dimensional color Doppler echocardiography applied for tricuspid regurgitation quantification

BACKGROUND

The two-dimensional (2D) proximal isovelocity surface area (PISA) method has known technical limitations, mainly the geometric assumptions of PISA shape required to calculate effective regurgitant orifice area (EROA). Recently developed single-beat real-time three-dimensional (3D) color Doppler imaging allows the direct measurement of PISA without geometric assumptions and has already been validated for mitral regurgitation assessment. The aim of this study was to apply this novel method in patients with chronic tricuspid regurgitation (TR).

METHODS

Ninety patients with chronic TR were enrolled. EROA and regurgitant volume (Rvol) were assessed using transthoracic 2D and 3D PISA methods. Quantitative Doppler and 3D transthoracic planimetry of EROA were used as reference methods.

RESULTS

Both EROA and Rvol assessed using the 3D PISA method had better correlations with the reference methods than using conventional 2D PISA, particularly in the assessment of eccentric jets. On the basis of 3D planimetry-derived EROA, 35 patients had severe TR (EROA ≥ 0.4 cm(2)). Among these 35 patients, 25.7% (n = 9) were underestimated as having nonsevere TR (EROA ≤ 0.4 cm(2)) using the 2D PISA method. In contrast, the 3D PISA method had 94.3% agreement (33 of 35) with 3D planimetry in classifying severe TR. Good intraobserver and interobserver agreement for 3D PISA measurements was observed, with intraclass correlation coefficients of 0.92 and 0.88 respectively.

CONCLUSIONS

TR quantification using PISA by single-beat real-time 3D color Doppler echocardiography is feasible in the clinical setting and more accurate than the conventional 2D PISA method.

Clinical context and mechanism of functional tricuspid regurgitation in patients with and without pulmonary hypertension

BACKGROUND

Functional tricuspid regurgitation (FTR) with structurally normal valve is of poorly defined mechanisms. Prevalence and clinical context of idiopathic FTR (Id-FTR) (without overt TR cause) are unknown.

METHODS AND RESULTS

To investigate prevalence, clinical context, and mechanisms specific to FTR types, Id-FTR versus pulmonary hypertension-related (PHTN-FTR, systolic pulmonary pressure ≥50 mm Hg), we analyzed 1161 patients with prospectively quantified TR. Id-FTR (prevalence 12%) was associated with aging and atrial fibrillation. For mechanistic purposes, we measured valvular and right ventricular (RV) remodeling in 141 Id-FTR matched to 140 PHTN-FTR and to 99 controls with trivial TR for age, sex, atrial fibrillation, and ejection fraction. PHTN-FTR and Id-FTR were also matched for TR effective-regurgitant-orifice (ERO). Id-FTR valvular alterations (versus controls) were largest annular area (3.53±0.6 versus 2.74±0.4 cm(2), P<0.0001) and lowest valvular/annular coverage ratio (1.06±0.1 versus 1.45±0.2, P<0.0001) but normal valve tenting height. PHTN-FTR had mild annular enlargement but excessive valve tenting height (0.8±0.3 versus 0.35±0.1 cm, P<0.0001). Valvular changes were linked to specific RV changes, largest basal dilatation, and normal length (RV conical deformation) in Id-FTR versus longest RV with elliptical/spherical deformation in PHTN-FTR. With increasing FTR severity (ERO ≥40 mm(2)), changes specific to each FTR type were accentuated, and RV function (index of myocardial performance) was consistently reduced.

CONCLUSIONS

Id-FTR is frequent, linked to aging and atrial fibrillation, can be severe, and is of unique mechanism. In Id-FTR, excess annular and RV-basal enlargement exhausts valvular/annular coverage reserve, and RV conical deformation does not cause notable valvular tenting. Conversely, PHTN-FTR is determined by valvular tethering with tenting linked to RV elongation and elliptical/spherical deformation. These specific FTR-mechanisms may be important in considering surgical correction in FTR.

Preoperative Factors Associated With Adverse Outcome After Tricuspid Valve Replacement

Background—

Preoperative factors associated with increased mortality and worse outcome after tricuspid valve replacement in patients with severe tricuspid regurgitation are poorly understood.

Methods and Results—

We retrospectively analyzed 189 patients (37% men; age, 67.5±11.3 years) who underwent tricuspid valve replacement for severe tricuspid regurgitation. Operative mortality rate was 10%, and was associated with intra-aortic balloon pump (odds ratio, 3.2; 95% confidence interval, 1.9 to 5.6; P <0.0001) or the presence of severe symptoms (New York Heart Association class IV relative to classes II and/or III) at the time of surgery (1.7; 95% confidence interval, 1.05 to 2.8; P =0.02). At the end of follow-up (29.3±27.1 months), 70 patients (37%) died, 6 (3%) needed tricuspid reoperation, and 41 (21.7%) were readmitted for heart failure. Seventy-eight patients (41.3%) were free from cardiovascular events (death, tricuspid reoperation, or heart failure admissions). The only echocardiographic parameter independently associated with adverse outcomes was a decrease in the right index of myocardial performance ratio. All-cause mortality was independently associated with a higher Charlson index (hazard ratio, 1.18; 95% confidence interval, 1.01 to 1.36; P =0.03), shorter right index of myocardial performance ratio (0.91; 95% confidence interval, 0.87 to 0.96; P =0.005), and preoperative New York Heart Association IV class (1.71; 95% confidence interval, 1.3 to 2.2; P <0.0001). In 68 patients with isolated tricuspid valve replacement, the associations between short right index of myocardial performance ratio, high Charlson index, New York Heart Association class IV, and increased mortality remained significant.

Conclusions—

Tricuspid valve replacement for severe tricuspid regurgitation can be performed with an acceptable operative mortality if patients undergo surgery before the onset of advanced heart failure symptoms. Late mortality is associated with a high preoperative Charlson index, short right index of myocardial performance ratio, and advanced New York Heart Association class.

Pathophysiology of Tricuspid Regurgitation

Background—

Respiratory dependence of tricuspid regurgitation (TR), a long-held concept suggested by murmur variation, remains unproven and of unclear mechanisms.

Methods and Results—

In 41 patients with mild or greater TR (median age, 67 years), we performed triple Doppler echocardiographic quantification (TR severity, right ventricular, and right atrial quantification) with simultaneous respirometer recording of respiratory phases. Expiration to inspiration changes (median) affected TR peak velocity (−40 cm/s; 25th to 75th percentile, −60 to −30 cm/s), duration (−12 milliseconds; 25th to 75th percentile, −45 to 2 milliseconds), and time-velocity integral (−17 cm; 25th to 75th percentile, −23.4 to −10 cm; all P <0.001), consistent with decreased TR driving force. Nevertheless, inspiratory TR augmentation was demonstrated by increased effective regurgitant orifice (0.21 cm 2 ; 25th to 75th percentile, 0.09 to 0.34 cm 2 ) and volume (18 mL per beat; 25th to 75th percentile, 10 to 25 mL per beat; all P <0.001) infrequently detected clinically (2 of 41, 5). As a result of reduced TR driving force, regurgitant volume increased less than effective regurgitant orifice (120 [25th to 75th percentile, 78.6 to 169] versus 169 [ 25th to 75th percentile, 12.9 to 226.1]; P <0.001). During inspiration, right ventricular area increased (diastolic, 27.8 [25th to 75th percentile, 22.6 to 36.3] versus 26.5 [21.1 to 31.9]; P <0.0001) with widening of right ventricular shape (length-to-width ratio, 1.6 [ 25th to 75th percentile, 1.37 to 1.95] versus 1.7 [1.46 to 2.1]; P <0.0001), increased systolic annular diameter ( P =0.003), valve tenting height ( P <0.0001) and area ( P <0.0001), and reduced valvular-to-annular ratio ( P =0.006). Effective regurgitant orifice during inspiration was independently determined by inspiratory valvular-to-annular ratio ( P =0.026) and inspiratory change in right ventricular length-to-width ratio ( P =0.008) and valve tenting area ( P =0.015).

Conclusions—

TR is dynamic with almost universal respiratory changes of large magnitude and complex pathophysiology. During inspiration, a large increase in effective regurgitant orifice causes, despite a decline in regurgitant gradient, a notable increase in regurgitant volume. Effective regurgitant orifice changes are independently linked to inspiratory annular enlargement (decreased valvular coverage) and to inspiratory right ventricular shape widening with increased valvular tenting. These novel physiological insights into TR respiratory dependence underscore right-side heart plasticity and are important for clinical TR severity evaluation.

Assessment of normal tricuspid valve anatomy in adults by real-time three-dimensional echocardiography

Background

The tricuspid valve (TV) is a complex structure. Unlike the aortic and mitral valve it is not possible to visualize all TV leaflets simultaneously in one cross-sectional view by standard two-dimensional echocardiography (2DE) either transthoracic or transesophageal due to the position of TV in the far field.

Aim

Quantitative and qualitative assessment of the normal TV using real-time 3-dimensional echocardiography (RT3DE).

Methods

RT3DE was performed for 100 normal adults (mean age 30 ± 9 years, 65% males). RT3DE visualization was evaluated by 4-point score (1: not visualized, 2: inadequate, 3: sufficient, and 4: excellent). Measurements included TV annulus diameters (TAD), TV area (TVA), and commissural width.

Results

In 90% of patients with good 2DE image quality, it was possible to analyse TV anatomy by RT3DE. A detailed anatomical structure including unique description and measurement of tricuspid annulus shape and size, TV leaflets shape, and mobility, and TV commissural width were obtained in majority of patients. Identification of each TV leaflet as seen in the routine 2DE views was obtained.

Conclusion

RT3DE of the TV is feasible in a large number of patients. RT3DE may add to functional 2DE data in description of TV anatomy and providing highly reproducible and actual reality (anatomical and functional) measurements.

The influence of sex on right ventricular dysfunction in patients with severely depressed left ventricular ejection fraction

AIM

To assess the influence of sex on right ventricular dysfunction (RVD) in patients with severe left ventricular systolic dysfunction.

METHODS AND RESULTS

We studied 385 consecutive patients with left ventricular ejection fraction (LVEF) <0.35. All patients underwent invasive measurement of right ventricular and pulmonary artery pressures and evaluation of RVD by standard transthoracic echocardiography. Female patients (n=84, 21.8%) were significantly older than male patients (62.0+/-11.4 vs. 58.2+/-10.7 years), p=0.005. The prevalence of RVD was lower in women (26.5%) than in men (38.9%), p=0.03; both in patients with and without coronary artery disease (19.4% vs. 34.5% and 31.9% vs. 44.4%, respectively). Haemodynamic parameters and LVEF were similar in men and women. Low LVEF, pulmonary systolic pressure, degree of mitral regurgitation, male sex, and absence of significant coronary artery disease were independently correlated with RVD.

CONCLUSION

Women with severe left ventricular systolic dysfunction have less RVD than men, despite similar haemodynamic parameters and LVEF.

Does lowering pulmonary arterial pressure eliminate severe functional tricuspid regurgitation?

OBJECTIVES

Because pulmonary thromboendarterectomy (PTE) can result in an immediate reduction in pulmonary artery (PA) pressure, we sought to evaluate the effect of PTE on severe tricuspid regurgitation (TR) without tricuspid annuloplasty.

BACKGROUND

Few data exist regarding the frequency and magnitude of functional TR improvement after reduction in PA pressure.

METHODS

We identified 27 patients with severe TR, defined by a regurgitant index (RI) >33%, who underwent PTE. The RI, tricuspid annular diameter (TAD), apical displacement of leaflet coaptation, and estimated PA systolic pressure were determined on pre- and post-PTE echocardiograms. Patients were stratified based on resolution (RI < or =33%) or persistence (RI >33%) of severe TR.

RESULTS

Comparing pre- and post-PTE echocardiography results, severe TR resolved in 19 of 27 (70%) patients. This group had a more effective PA systolic pressure reduction after PTE (49 +/- 20 mm Hg vs. 32 +/- 16 mm Hg by echocardiography, p = 0.075, and 37 +/- 16 mm Hg vs. 16 +/- 13 mm Hg by catheter measurement, p = 0.004). No difference was observed in TAD, apical displacement of the tricuspid valve, or other features compared with the group with persistent severe TR. There was a trend toward longer hospital stays in the group with persistent severe TR (19 +/- 15 days vs. 14 +/- 9 days; p = 0.55).

CONCLUSIONS

After significant PA pressure reduction by PTE, severe functional TR with a dilated annulus may improve without annuloplasty despite dilated tricuspid annulus diameters.

Reproducibility of the proximal flow convergence method in mitral and tricuspid regurgitation

BACKGROUND

The follow-up of patients with mitral and tricuspid regurgitation is important for their clinical treatment. We aimed to evaluate the reproducibility of the flow convergence method in mitral and tricuspid regurgitation.

METHODS

The proximal flow convergence region was imaged with color Doppler ultrasound scanning echocardiography in 83 patients with mitral regurgitation, tricuspid regurgitation, or both. Proximal isovelocity surface area radii for aliasing velocities of 27 to 29 cm/s and 41 to 43 cm/s were repeatedly measured by the same experienced investigator on different days and by experienced and less experienced investigators at 1 day.

RESULTS

In mitral regurgitation, the intraobserver variability rate was 0.2% +/- 13.5% (2.8% +/- 13.3%) and the interobserver variability was 0.1% +/- 13.8% (1.7% +/- 18.0%) for an aliasing velocity of 27 to 29 cm/s (41-43 cm/s). For the aliasing velocity of 27 to 29 cm/s (41-43 cm/s), the 95% ranges for change of the proximal isovelocity surface area radii were +/- 2.7 mm (+/- 1.8 mm) for measurements repeated by the same investigator and +/- 2.7 mm ( +/- 2.4 mm) for different investigators. Interobserver variability was independent of the investigators' experience. Similar data were achieved in tricuspid regurgitation.

CONCLUSIONS

The proximal flow convergence method is acceptably reproducible in mitral and tricuspid regurgitation independent of the investigators experience. For the aliasing velocity of 27 to 29 cm/s (41-43 cm/s), the proximal isovelocity surface area radius has to change for >2.7 (2.4) mm before an altered severity of mitral or tricuspid regurgitation in a single patient can be assumed.

Contrasting effect of similar effective regurgitant orifice area in mitral and tricuspid regurgitation: a quantitative Doppler echocardiographic study

We compared the effect of similar effective regurgitant orifice (ERO) areas in tricuspid regurgitation (TR) and mitral regurgitation (MR) on hemodynamics and volume overload, and examined the impact on grading of TR and MR severity. In a prospective study, 95 patients with TR in sinus rhythm were compared with 95 patients with MR in sinus rhythm matched for ERO area, age, and body surface area. We found that similar ERO area was associated with decreased volume overload in TR compared with MR. There were more women with TR than with MR, but comparison stratified by sex confirmed that regurgitant volume (RVol) was smaller in TR than in MR for similar ERO area. However, patients with systolic venous flow reversal (hepatic for TR and pulmonary for MR) had lower RVol but similar ERO area in TR compared with MR. Therefore, optimal diagnostic thresholds for severe regurgitation (maximum sum of sensitivity and specificity) in TR and MR were different for RVol (45 and 60 mL/beat, respectively) but similar for ERO area (40 mm(2)). We conclude that similar ERO areas induce less RVol in TR than in MR because of the decreased driving force in TR, but have similar consequences with regard to venous flow reversal. Therefore, a similar ERO area grading scheme can be used, and an ERO area of 40 mm(2) or greater is consistent with severe regurgitation in both TR and MR.

Quantification of tricuspid regurgitation by measuring the width of the vena contracta with Doppler color flow imaging: a clinical study

OBJECTIVE

We sought to evaluate the vena contracta width (VCW) measured using color Doppler as an index of severity of tricuspid regurgitation (TR).

BACKGROUND

The VCW is a reliable measure of mitral and aortic regurgitation, but its value in measuring TR is uncertain.

METHODS

In 71 consecutive patients with TR, the VCW was prospectively measured using color Doppler and compared with the results of the flow convergence method and hepatic venous flow, and its diagnostic value for severe TR was assessed.

RESULTS

The VCW was 6.1+/-3.4 mm and was significantly higher in patients with, than those without, severe TR (9.6+/-2.9 vs. 4.2 +/- 1.6 mm, p<0.0001). The VCW correlated well with the effective regurgitant orifice (ERO) by the flow convergence method (r = 0.90, SEE = 0.17 cm2, p<0.0001), even when restricted to patients with eccentric jets (r = 0.93, p < 0.0001). The VCW also showed significant correlations with hepatic venous flow (r = 0.79, p < 0.0001), regurgitant volume (r = 0.77, p<0.0001) and right atrial area (r = 0.46, p< 0.0001). A VCW > or =6.5 mm identified severe TR with 88.5% sensitivity and 93.3% specificity. In comparison with jet area or jet/right atrial area ratio, the VCW showed better correlations with ERO (both p<0.01) and a larger area under the receiver operating characteristic curve (0.98 vs. 0.88 and 0.85, both p<0.02) for the diagnosis of severe TR.

CONCLUSIONS

The VCW measured by color Doppler correlates closely with severity of TR. This quantitative method is simple, provides a high diagnostic value (superior to that of jet size) for severe TR and represents a useful tool for comprehensive, noninvasive quantitation of TR.

Assessment of valvular regurgitation with Doppler echocardiography

Echocardiography is routinely performed for the evaluation of valvular regurgitation. Different applications of Doppler echocardiography have been successfully applied to detect and quantify valvular regurgitation. Recent advances in color Doppler made possible the study of the dynamic behavior of the regurgitant orifice and, along with continuous wave Doppler, can provide data on the regurgitant volume and fraction. Doppler echocardiography can also be used to follow serial changes in these hemodynamically important parameters after medical or surgical therapy.

Tricuspid valve disease. Clinical evaluation, physiopathology, and management

The tricuspid and mitral valves are homologous whose function depends on coordination among components. Isolated tricuspid valve abnormalities are relatively uncommon. Rheumatic disease, chemicals, immunologic and degenerative disorders alter leaflet anatomy and may result in either stenosis, insufficiency or a combination. More often, tricuspid disorders present as a component of congenital syndromes or secondary to pulmonary vascular or let heart disease which alter geometry and function of nonleaflet components.

Quantifying aortic regurgitation by using the color Doppler-imaged vena contracta: a chronic animal model study

BACKGROUND

The aim of the present study was to evaluate the accuracy of determining aortic effective regurgitant orifice area (EROA) and aortic regurgitant volume by using the color Doppler-imaged vena contracta (CDVC).

METHODS AND RESULTS

Twenty-nine hemodynamically different states were obtained pharmacologically in eight sheep with surgically induced aortic regurgitation. Instantaneous regurgitant flow rates (RFRs) were obtained with aortic and pulmonary electromagnetic flowmeters (EFMs), and aortic EROAs were determined from EFM RFRs divided by continuous wave Doppler velocities. Color Doppler-derived EROAs were estimated by measuring the maximal diameters of the CDVC. Peak and mean RFRs and regurgitant volumes per beat were calculated from vena contracta area continuous wave diastolic Doppler velocity curves. Peak EFM-derived RFRs varied from 1.8 to 13.6 (6.3+/-3.2) L/min (range [mean+/-SD]), mean RFRs varied from 0.7 to 4.9 (2.7+/-1.3) L/min, regurgitant volumes per beat varied from 7.0 to 48.0 (26.9+/-12.2) mL/beat, and the regurgitant fractions varied from 23% to 78% (55+/-16%). EROAs determined by using CDVC measurements correlated well with reference EROAs obtained by using the EFM method (r=.91, SEE=0.07 cm2). Excellent correlations and agreements between peak and mean RFR and regurgitant volumes per beat as determined by Doppler echocardiography and EFM were also demonstrated (r=.95 to .96).

CONCLUSIONS

Our study indicates that the CDVC method can be used to quantify both aortic EROAs and regurgitant flow rates.

Current status of flow convergence for clinical applications: is it a leaning tower of "PISA"?

Spatial appreciation of flow velocities using Doppler color flow mapping has led to quantitative evaluation of the zone of flow convergence proximal to a regurgitant orifice. Based on the theory of conservation of mass, geometric analysis, assuming a series of hemispheric shells of increasing velocity as flow converges on the orifice--the so-called proximal isovelocity surface area (PISA) effect--has yielded methods promising noninvasive measurement of regurgitant flow rate. When combined with conventional Doppler ultrasound to measure orifice velocity, regurgitant orifice area, the major predictor of regurgitation severity, can also be estimated. The high temporal resolution of color M-mode can be used to evaluate dynamic changes in orifice area, as seen in many pathologic conditions, which enhances our appreciation of the pathophysiology of regurgitation. The PISA methodology is potentially applicable to any restrictive orifice and has gained some credibility in the quantitative evaluation of other valve pathology, particularly mitral and tricuspid regurgitation, and in congenital heart disease. Although the current limitations of PISA estimates of regurgitation have tempered its introduction as a valuable clinical tool, considerable efforts in in vitro and clinical research have improved our understanding of the problems and limitations of the PISA methodology and provided a firm platform for continuing research into the accurate quantitative assessment of valve regurgitation and the expanding clinical role of quantitative Doppler color flow mapping.