Tricuspid Regurgitation Peak-to-Mean Velocity Ratio: Linking Doppler Morphology to Right Heart Hemodynamics in Pulmonary Hypertension.

BACKGROUND

The peak-to-mean tricuspid regurgitation velocity ratio (Vmax/Vmean) is a quantitative descriptor of continuous-wave Doppler waveform morphology. Its physiologic and clinical significance in pulmonary hypertension (PH) remains incompletely characterized. We investigated the relationship among Vmax/Vmean, right heart structure and function, and clinical outcomes in patients with precapillary PH.

METHODS

This single-center cohort study included 203 patients with precapillary PH. Baseline echocardiography was performed near the time of right heart catheterization, with repeat echocardiography after initiation of PH-targeted therapy. Vmax/Vmean was analyzed in relation to structural, functional, and hemodynamic variables using linear regression and linear mixed-effects models. The end point was a composite of all-cause mortality or hospitalization for heart failure. Survival analysis was performed using Kaplan-Meier curves and Cox proportional-hazards regression models.

RESULTS

Vmax/Vmean increased with rising pulmonary artery systolic pressure (PASP), reflecting deviation from proportional velocity scaling at high afterload, despite a strong correlation between Vmax and Vmean (r = 0.96). Higher Vmax/Vmean values were associated with right ventricular systolic dysfunction, tricuspid regurgitation severity, right chamber remodeling, and elevated right atrial pressure. Vmax/Vmean also correlated with invasive parameters, including mean pulmonary artery pressure and pulmonary vascular resistance (P < .001 for all). Posttreatment Vmax/Vmean was independently associated with adverse outcomes after adjustment for PASP and clinical covariates (adjusted hazard ratio, 1.7; 95% CI, 1.3-2.3; P < .001) and provided incremental value beyond PASP.

CONCLUSIONS

Vmax/Vmean reflects tricuspid regurgitation continuous-wave Doppler morphology and right ventricular adaptation to pulmonary vascular load. Persistent elevation after PH-targeted therapy identifies patients with adverse hemodynamic profiles and increased risk for death or heart failure hospitalization.