Myocardial work of the systemic right ventricle and its association with outcomes.

Abstract

We aimed to evaluate clinical and prognostic significance of myocardial work parameters of the systemic right ventricle (SRV). Thirty-eight patients with the SRV underwent echocardiographic assessment of the SRV systolic function including 3D-echocardiography derived ejection fraction, 2D longitudinal strain and myocardial work analysis. The study endpoint was the combination of all-cause mortality and heart transplantation. Global constructive work (GCW) and global work index (GWI) demonstrated moderate correlation with the 3DE-derived SRV ejection fraction (EF) (Rho 0.64, p<0.0001 and Rho 0.63, p<0.0001, respectively). GCW showed the strongest correlation with the BNP level (Rho -0.77, p<0.0001), closely followed by GWI, 4-chamber longitudinal strain and 3DE EF (all Rho -0.73, p<0.0001). GCW and GWI were significantly lower in patients with moderate or severe tricuspid regurgitation compared with less than moderate regurgitation (1226±439 vs 1509±264mmHg%, p=0.02, and 984±348 vs 1259±278mmHg%, p=0.01, respectively). During a follow-up of 3.5 (2.8-3.9) years, seven patients (18%) died and one received transplantation (3%). They had significantly lower GCW and GWI compared with patients who did not reach the study endpoint (908±255 vs 1433±%, p<0.001 and 721±210 vs 1173±315 mmHg%, p<0.001, respectively). In Cox regression analysis, GCW, GWI, 3DE SRV volumes and EF were the best-fit models based on the Akaike Information Criterion, outperforming longitudinal strain parameters. GWI and GCW, novel echocardiographic parameters of myocardial work, provided reliable quantification of the SRV systolic function. GWI, GCW and 3DE-derived SRV parameters were closely associated with all-cause mortality and heart transplantation in patients with the SRV.