Right ventricular myocardial work: new method for non-invasive assessment of right ventricular function in HFrEF

Abstract

Abstract Background The prognostic significance of speckle tracking echocardiography derived right ventricular (RV) strain has been repeatedly demonstrated in the heart failure with reduced ejection fraction (HFrEF) patient group. Nevertheless, assessing RV systolic function in the context of afterload is vital as even minimal increases in pulmonary pressures may result in a substantial reduction in RV stroke volume. The novel assessment of Right Ventricular Myocardial Work (RVMW) through the evaluation of pressure-strain loops derived by echocardiography, provides a comprehensive evaluation of RV systolic function, integrating both RV strain and afterload. Purpose To explore the relationship between the non-invasive estimation of RVMW with invasive indices of right heart catherization (RHC) in a cohort of patients with HFrEF. Methods Noninvasive analysis of RVMW was performed in 23 HFrEF patients (median age 60.4 [58.0 to 66.0] years, 74% male) who underwent echocardiography and invasive RHC within 48 hours. The novel indices of RV global constructive work (RVGCW), RV global work index (RVGWI), RV wasted work (RVWW) and RV global work efficiency (RVGWE) were analysed utilizing proprietary software originally developed for the assessment of left ventricular myocardial work by speckle tracking echocardiography. These indices and other standard measurements of RV systolic function were then compared with invasively measured cardiac index (CI), derived by thermodilution during RHC. Results Mean left ventricular ejection fraction was 18.7% (±6.7), with a mean cardiac index of 2.2 L/min/m2(±0.7) and a mean pulmonary arterial pressure of 32 mm Hg (±13). None of the standard echocardiographic parameters of RV systolic function, including fractional area change, RV global longitudinal strain, RV free wall strain and TAPSE were significantly correlated with cardiac index in this cohort of HFrEF patients. In contrast, two of the novel indices derived non-invasively by pressure-strain loops, RVGCW and RVGWI, demonstrated a moderate correlation with invasively measured CI (r=0.55, p=0.006 and r=0.49, p=0.018). Conclusion RVGCW and RVGWI are novel parameters that provide integrative analysis of RV systolic function and correlate more closely with invasively measured CI than other standard echocardiographic parameters. Their potential role in aiding clinical decision-making merits further investigation. Funding Acknowledgement Type of funding source: None