P1515 Hemodynamic determinants of tricuspid annular pulmonary systolic excursion (TAPSE)/ systolic pulmonary arterial pressure (SPAP) ratio in Heart Failure with reduced Ejection Fraction

Background

the TAPSE/SPAP ratio has gained a role as an easy-to-use surrogate of right ventricle-to-pulmonary circulation (RV-PC) coupling, showing a strong prognostic significance in heart failure (HF) patients. The hemodynamic determinants of TAPSE/SPAP ratio, as assessed by invasive approach, have not been fully clarified.

Aim

To identify the right heart hemodynamic variables correlated with TAPSE/SPAP in a HF with reduced EF (HFrEF) cohort, both at rest and during exercise.

Methods

30 HFrEF patients (age 68 ± 10 years LV EF 28 ± 7) underwent to rest and exercise echocardiography and performed right heart catheterization within 24 hours. Bivariate correlations between TAPSE/SPAP ratio (at rest and during exercise), right heart hemodynamic variables, RV systolic function and NTproBNP have been explored.

Results

TAPSE/SPAP ratio at rest showed a moderate correlation with pulmonary artery wedge pressure (PAWP: r= 0.441; p= 0.039), pulmonary artery pressures (PAP systolic: r = 0.481; p= 0.026; PAP diastolic: r= 0.434; p= 0.043; mPAP: r= 0.476; p= 0.025), pulmonary vascular resistance and compliance (r= 0.475; p= 0.041). A stronger correlation was identified with right atrial (RAP systolic: r= 0.586; p= 0.017; RAP diastolic: r= 0.681; p= 0.006) and right ventricular pressures- in particular diastolic ones (RVP systolic: r= 0.584; p= 0.004; RAP diastolic: r= 0.652; p= 0.002). No significant correlation with NTproBNP and RV 3D EF emerged. Exercise TAPSE/SPAP ratio significantly correlated with right atrium (RAP systolic: r= 0.564; p= 0.036) and right ventricle systolic pressures only (RVP systolic: r= 0.789; p< 0.001).

Conclusions

TAPSE/SPAP ratio at rest showed a stronger correlation with invasively derived diastolic right heart pressure rather than pulmonary vascular bed pressures. A similar correlation was also observed for exercise TAPSE/SPAP ratio. This tight correlation with RV, rather than with vascular pressures, supports the significance of this ratio as a marker of RV adaptation to vascular overload.

P1410 Right ventricle to pulmonary circulation coupling is primarily defined by the circumferential right ventricle function

Background

Right ventricle to pulmonary circulation (RV-PC) coupling plays a pivotal role during the physical effort. The RV-PC uncoupling can be easily identified by the TAPSE/SPAP ratio, a prognostic marker based on RV longitudinal function and its afterload (SPAP).We sought to explore the relationship between the functional capacity (peak VO2 and VE/VCO2) and the RV-PC coupling, using both a standard and 3D-based echocardiographic assessment of RV.

Methods

eighty-seven patients (age 72 ± 10 years; LV EF 53 ± 15%) underwent rest echocardiography with 3D RV assessment and cardiopulmonary exercise test. RV EF was measured using the 4D RV TomTec software. The 3D mesh of the RV model was post-processed using a custom developed software. This provided longitudinal (EFlong) and circumferential (EFcirc) components of EF. RV-PC coupling was assessed with the TAPSE/SPAP ratio and with similar parameters obtained by using 3D components of RV systolic function over SPAP (EF/SPAP, EFlong/SPAP and EFcirc/SPAP ratio). All variables were correlated with peakVO2 and VE/VCO2.

Results

Correlations between peakVO2 and TAPSE (0.409, p = 0.006), SPAP (-0.597, p < 0.001), RV EF (0.555, p < 0.001), RV EFlong (0.327, p = 0.03), RV EFcirc (0.587, p < 0.001) were modest, while TAPSE/SPAP (0.641, p < 0.001), EF/SPAP (0.751, p < 0.001), EFlong/SPAP (0.610, p < 0.001) and EFcirc/SPAP (0.775, p < 0.001) showed stronger correlations. VE/VCO2 showed a similar relationships although the correlations were weaker [TAPSE (-0.523, p <0.001), SPAP (0.617, p < 0.001), RV EF (-0.412, p = 0.006), RV EFlong (-0.232, p = 0.129), RV EFcirc (-0.454, p = 0.002), TAPSE/SPAP (-0.561, p < 0.001), EF/SPAP (-0.516, p = 0.001), EFlong/SPAP (-0.429, p = 0.008) and EFcirc/SPAP (-0.541, p < 0.001)].

Conclusions

RV-PC coupling is associated with both peak VO2 and VE/VCO2. The use of 3D-derived markers of RV-PC coupling showed a better correlation with the peak VO2, while there were no differences for VE/VCO2. The circumferential component of RV systolic function seems to emerge as a dominant determinant of RV-PC coupling, as well as of functional capacity.