Right Ventricular Myocardial Work Characterization in Patients With Pulmonary Hypertension and Relation to Invasive Hemodynamic Parameters and Outcomes

Abstract

Noninvasive evaluation of indexes of right ventricular (RV) myocardial work (RVMW) derived from RV pressure-strain loops may provide novel insights into RV function in precapillary pulmonary hypertension. This study was designed to evaluate the association between the indexes of RVMW and invasive parameters of right heart catheterization and all-cause mortality. Noninvasive analysis of RVMW was completed in 51 patients (mean age 58.1 ± 12.7 years, 31% men) with group I or group IV pulmonary hypertension. RV global work index (RVGWI), RV global constructive work (RVGCW), RV global wasted work (RVGWW), and RV global work efficiency (RVGWE) were compared with parameters derived invasively during right heart catheterization. Patients were followed-up for the occurrence of all-cause death. The median RVGWI, RVGCW, RVGWW, and RVGWE were 620 mm Hg%, 830 mm Hg%, 105 mm Hg% and 87%, respectively. Compared with conventional echocardiographic parameters of RV systolic function, RVGCW and RVGWI correlated more closely with invasively derived RV stroke work index (R=0.63, p <0.001 and R=0.60, p <0.001, respectively). Invasively derived pulmonary vascular resistance correlated with RVGWW (R=0.63, p <0.001), RVGWE (R=0.48, p <0.001), and RV global longitudinal strain (R=0.58, p <0.001). RVGCW (hazard ratio 1.42 per 100 mm Hg% <900 mm Hg%, 95% confidence interval 1.12 to 1.81, p=0.004) and RVGWI (hazard ratio 1.46 per 100 mm Hg% <650 mm Hg%, 95% confidence interval 1.09 to 1.94, p=0.010) were significantly associated with all-cause mortality, whereas RV global longitudinal strain, RVGWE, and RVGWW were not. In conclusion, indexes of RVMW were more closely correlated with invasively derived RV stroke work index and peripheral vascular resistance than conventional echocardiographic parameters of RV systolic function. Decreased values of RVGCW and RVGWI were associated with all-cause mortality, whereas conventional echocardiographic parameters of RV function were not.