Echocardiographic Estimation of right ventricular stroke work index based on pulmonary regurgitant velocity in heart...

Right ventricular (RV) dysfunction is a key determinant of mortality in heart failure with reduced left ventricular ejection fraction (HFrEF). RV stroke work index (RVSWI) is an established invasive parameter of RV function; however, echocardiographic methods for estimating RVSWI have not yet been fully established. We hypothesized that the pulmonary regurgitant (PR) velocity waveform-derived early-diastolic pulmonary artery-RV pressure gradient (PRPG) would allow an accurate estimation of RVSWI because of its fidelity to the original formula. This study aimed to investigate whether non-invasive estimation of RVSWI is feasible in patients with HFrEF.

In this retrospective study, 120 adult patients with HFrEF who underwent right heart catheterization within 24 h of echocardiography were included. RVSWI was calculated as (mean pulmonary artery pressure - mean right atrial pressure) × stroke volume index (SVI). Based on the continuous-wave Doppler velocity measurements of PR, echocardiographic estimation of RVSWI was calculated as PRPG × pulsed-wave Doppler-derived SVI (RVSWI_PR).

The RVSWI_PR was significantly correlated with RVSWI (ρ = 0.670, p < 0.001). Bland-Altman analysis showed no direct fixed bias. Sensitivity analysis performed in 21 patients with HFrEF and severe tricuspid regurgitation, which is a challenging subgroup for non-invasive RV function assessment, showed similar results. In the receiver operating characteristic curve analyses to detect the patients with RVSWI < 250 mmHg∙mL/m², the area under the curve was 0.954, and a cut-off value of 371 mmHg∙mL/m² showed 100% sensitivity and 82% specificity.

RVSWI_PR, based on PR velocity waveform analysis, was useful for the non-invasive assessment of RVSWI in HFrEF.