Beyond effective regurgitant orifice in quantitative assessment of tricuspid regurgitation: impact on clinical outcomes

Abstract

Abstract Background Quantification in tricuspid regurgitation has been poorly investigated. Recommended methods and thresholds are directly translated from mitral regurgitation; however, the anatomy, hemodynamics, and regurgitant orifice geometry are different in TR. Effective regurgitant orifice (ERO) calculation may be incorrect in very severe TR when right atrial and ventricular pressures could get equalized resulting in typically very low TR velocities. Purpose Our aim was to compare the prognostic value of different parameters for the evaluation of the tricuspid regurgitation (TR). Methods Consecutive patients with significant TR (≥ moderate echocardiographic grade) evaluated in the Heart Valve Clinic were included. TR severity was evaluated by TR radius, TR flow rate, ERO and TR regurgitant volume by PISA method and biplane vena contracta (VC) width using EPIQ system. End-point included cardiovascular mortality, tricuspid valve surgery or heart failure. Results A total of 100 patients were included (mean age: 76±10 years, 65% females, 86% functional TR, 84% in NYHA I/II). During a mean follow up of 24±10 months 36% of the patients reached the combined end-point. Patients with events showed more severe TR independently of the parameter applied (table). In univariate analysis, TR radius, TR flow rate, ERO and TR regurgitant volume were predictors of the combined endpoint (p<0.05 for all). Among all parameters, TR flow rate was the strongest and independent predictor of outcomes in multivariate and ROC analysis (HR per 1 ml/seg 1.02 [1.003–1.026], p=0.01). A value of TR flow rate of 109 ml/sec reached the best accuracy to predicted poor outcomes (p<0.01). Conclusion Among different parameters to graduate TR severity, TR flow rate was the strongest predictor of outcomes. Since it does not include the TR velocity in the calculation, its incremental benefit may be related to very severe cases of TR. In this scenario, right atrial and ventricular pressures are equalized and TR velocity calculation is not longer possible. New grading schemes for TR may include this parameter in the classification. Funding Acknowledgement Type of funding source: None