Right ventricular myocardial work characterization in patients with pulmonary hypertension and association with pulmonary hypertension severity

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Right ventricular myocardial work (RVMW) assessed by transthoracic echocardiography allows to study and analyze the right ventricular (RV) function non-invasively, using RV pressure-strain loops. The association between these novel indexes of RVMW and invasive hemodynamic parameters has not yet been extensively studied, namely in precapillary pulmonary hypertension (PH) population. Objectives To evaluate the relationship between RVMW and the severity of PH through invasive indices of right heart catheterization (RHC) in a cohort of patients with group I and group IV PH. Methods A prospective registry of pre-capillary PH patients evaluated in a single tertiary center was used. Echocardiography and right heart catheterization were performed in the same day. Dedicated software for left ventricle myocardial work was used for the RV. RV global myocardial work index (RVGWI) was calculated as the area of the RV pressure-strain loops. From RVGWI, RV global constructive work (RVGCW; work contributing to myocardial shortening during systole and lengthening during isovolumic relaxation), RV global wasted work (RVGWW; work contributing to myocardial lengthening during systole and shortening during isovolumic relaxation), and RV global work efficiency (RVGWE; relation between RVGCW and RVGWW) were estimated. Pearson’s correlation was applied to assess correlations between continuous variables. Results 17 pts (80% women, mean age 67 ± 10 years) were included. Conventional echocardiographic parameters for the evaluation of RV systolic function, such as TAPSE, annular tricuspid s’ velocity and fractional area change (FAC), did not correlate with mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR). Strong correlations were found between right ventricle-pulmonary artery (RV-PA) coupling and mPAP (r = -0,655, p = 0,006) and RVP(r = - 0,610, p = 0,017), as well as with RV GLS (r = 0,749, p = 0,001 and r = 0,622, p = 0,01, respectively). Of the RVMW indexes, RVGWI, RVGWW and RVGWE strongly correlated with mPAP and PVR: as these invasive parameters increase, RVGWI (r = -0,581, p = 0,015 and r = -0,536, p = 0,027, respectively) and RVGWE (r = -0,779, p < 0,001 and r = -0,773, p < 0,001, respectively) decline significantly, whereas RVGWW (r = 0,735, p = 0,001 and r = 0,800, p < 0,001) increases. In our population, only RVGCW didn’t correlate significantly with high afterload (r= −0,304, p = 0,235 for mPAP, and r = -0,181, p = 0,488 for RVP). Conclusions New methods to evaluate RV function are crucial in patients with RV hemodynamic overload, since conventional echocardiographic parameters do not perform well. Novel echocardiographic assessment of RVMW are associated with severity of PH in our population.