Ratio between Vena Contracta Width and Tricuspid Annular Diameter: Prognostic Value in Secondary Tricuspid Regurgitation

Background: Conventional approaches for the assessment of secondary tricuspid regurgitation (STR) severity do not correct for right heart dimensions. The authors hypothesized that STR severity can be proportional or disproportional to the dilation of the tricuspid annulus (TA) and investigated the prognostic impact of this novel definition. Methods: A total of 334 patients with moderate to severe STR and preserved left ventricular systolic function were included. The ratio between vena contracta (VC) width and tricuspid annular diameter was calculated. The cutoff value for VC/TA ratio associated with increased risk for all-cause death was identified using spline-curve analysis. Results: The cutoff value of VC/TA ratio associated with a mortality excess was 0.24, and 165 patients (49%) had VC/TA ratios >_ 0.24. Compared with those with VC/TA ratios < 0.24, patients with VC/TA ratios >_ 0.24 had a higher prevalence of moderate to severe mitral regurgitation, had higher pulmonary pressures, and were more frequently treated with diuretics. During a median follow-up period of 62 months (interquartile range, 28-101 months), 128 patients (38%) died. The cumulative 5-year survival rate was significantly worse in patients with VC/TA ratios >_ 0.24 (55% vs 71%, P = .001). VC/TA ratio >_ 0.24 was independently associated with poor outcomes on multivariate analysis (hazard ratio, 1.567; 95% CI, 1.044-2.352; P = .030) together with coronary artery disease, renal impairment, right ventricular systolic function (evaluated using either tricuspid annular plane systolic excursion or right ventricular free wall strain), and pulmonary pressures. Conclusions: VC/TA ratio >_ 0.24 is independently associated with poor prognosis in patients with STR. This parameter may be considered as a marker of disproportionate STR and could improve risk stratification and clinical decision-making. (J Am Soc Echocardiogr 2021;34:944-54.)