Prevalence, Burden and Echocardiographic Features of Moderate to Severe Tricuspid Regurgitation: Insights from a Tertiary Referral Center

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.

Tricuspid Regurgitation in Left Ventricular Systolic Dysfunction: Marker or Target?

Far from being historically considered a primary healthcare problem, tricuspid regurgitation (TR) has recently gained much attention from the scientific community. In fact, in the last years, robust evidence has emerged regarding the epidemiological impact of TR, whose prevalence seems to be similar to that of other valvulopathies, such as aortic stenosis, with an estimated up to 4% of people >75 years affected by at least moderate TR in the United States, and up to 23% among patients suffering from heart failure with reduced ejection fraction. This recurrent coexistence of left ventricular systolic dysfunction (LVSD) and TR is not surprising, considered the multiple etiologies of tricuspid valve disease. TR can complicate heart failure mostly as a functional disease, because of pulmonary hypertension (PH), subsequent to elevated left ventricular end-diastolic pressure, leading to right ventricular dilatation, and valve tethering. Moreover, the so-called "functional isolated" TR can occur, in the absence of PH, as a result of right atrial dilatation associated with atrial fibrillation, a common finding in patients with LVSD. Finally, TR can result as a iatrogenic consequence of transvalvular lead insertion, another frequent scenario in this cohort of patients. Nonetheless, despite the significant coincidence of these two conditions, their mutual relation, and the independent prognostic role of TR is still a matter of debate. Whether significant TR is just a marker for advanced left-heart disease, or a crucial potential therapeutical target, remains unclear. Aim of the authors in this review is to present an update concerning the epidemiological features and the clinical burden of TR in the context of LVSD, its prognostic value, and the potential benefit for early tricuspid intervention in patients affected by contemporary TR and LVSD.

Functional and Echocardiographic Improvement After Transcatheter Repair for Tricuspid Regurgitation: A Systematic Review and Pooled Analysis

OBJECTIVES

The aim of this study was to assess the feasibility, efficacy, and clinical outcomes of transcatheter repair of tricuspid regurgitation (TR) in a pooled analysis of interventional studies.

BACKGROUND

New percutaneous devices are available to treat severe TR, but the evidence is sparse and limited to smaller cohorts.

METHODS

Several electronic databases were searched for interventional studies involving percutaneous repair of TR. Devices used were the Cardioband, FORMA, MitraClip, PASCAL, and Trialign. Outcomes included in the final analysis were successful implantation, residual severe TR, post-procedural New York Heart Association (NYHA) functional class III or IV, 6-min walk distance, and echocardiographic parameters. Subgroup and meta-regression analysis were performed to further explore residual heterogeneity.

RESULTS

Seven studies and 454 patients undergoing transcatheter tricuspid valve repair were included in the pooled analysis; 95% of patients had at least severe TR, and 91% were in NYHA functional class III or IV. Successful implantation was achieved in 86% of patients. At the longest follow-up available (weighted mean 265 days), 9% had died. Compared with baseline, a significantly lower proportion of patients had at least severe TR (relative risk: 0.38; 95% confidence interval: 0.20 to 0.70; p = 0.004) and were in NYHA functional class III or IV (relative risk: 0.23; 95% confidence interval: 0.20 to 0.30; p < 0.001). Patients also experienced increases in 6-min walk distance (mean difference +64.6 m; p < 0.001) and significant reductions in tricuspid valve annular diameter (mean difference -3 mm; p < 0.001), while left and right ventricular function did not change significantly.

CONCLUSIONS

A strategy of transcatheter repair for severe TR appears to be feasible, effective, and associated with improved clinical outcomes at mid-term follow-up.