Prognostic Value of the Right Ventricular-to-Left Ventricular Volume Ratio in Tricuspid Regurgitation

Abstract

Background

Tricuspid regurgitation (TR) is associated with right ventricular (RV) remodeling; however, conventional RV metrics may not fully reflect the interplay between the right and left ventricles.

Objectives

The aim of the study was to examine the prognostic value of the right ventricular-to-left ventricular volume ratio (RV/LV_vol) ratio in TR.

Methods

A retrospective analysis was conducted on 949 patients with ≥moderate TR who underwent cardiac magnetic resonance imaging between 2005 and 2024. The RV/LV_vol ratio was assessed as a dichotomous variable (normal: <1.27, abnormal: ≥1.27) and by severity strata. Follow-up data, including all-cause mortality, were collected using the Social Security Death Index and electronic medical records.

Results

Of the 949 patients, 43.6% had an abnormal RV/LV_vol ratio. Among 528 patients with a normal RV end-diastolic volume index, 178 (33.7%) had an abnormal RV/LV_vol ratio. Over a mean follow-up of 4.8 ± 4.5 years, 236 patients died. An abnormal RV/LV_vol ratio was independently associated with increased mortality after adjusting for covariates (adjusted HR: 1.47, 95% CI: 1.01 to 2.14, P = 0.043). Mortality risk increased with RV/LV_vol ratio severity, with severe ratios conferring the highest risk (adjusted HR: 2.20, 95% CI: 1.31-4.76, P = 0.045). The RV/LV_vol ratio provided significant incremental prognostic value over conventional RV indices, improving global chi-square from 24.7 (age/sex) to 47.1 with RV ejection fraction, 59.3 with RV end-diastolic volume index, and 68.3 with the addition of RV/LV_vol ratio (P = 0.005).

Conclusions

The RV/LV_vol ratio is a strong predictor of mortality in advanced TR, capturing ventricular remodeling not identified by conventional metrics.