The application value of right ventricular pulmonary artery coupling to predict exercise intolerance as an alternative to the six-minute walk test in patients with chronic heart failure with reduced ejection fraction.

Abstract

Introduction: In managing patients with heart failure, especially those with HFrEF, anticipating exercise intolerance is crucial. The 6-minute walk test (6-MWT) is a common and straightforward method for evaluating exercise capacity. Right ventricular–pulmonary artery (RV-PA) coupling, often assessed by the ratio of tricuspid annular plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP), has been suggested to correlate with the 6-MWT results in previous studies. However, TAPSE/PASP is just one of several RV-PA coupling parameters; others include the right ventricular fractional area change to right ventricular systolic pressure (RV-FAC/RVSP) and the tricuspid annulus systolic velocity to right ventricular systolic pressure (S'/RVSP). This study aims to evaluate RV-PA coupling characteristics and examine how TAPSE/PASP, and other RV-PA coupling parameters, correlate with the six-minute walk distance (6-MWD) in HFrEF patients, with the goal of determining if RV-PA coupling could serve as a viable alternative to the 6-MWT for predicting exercise capacity in these patients.

Aims: We investigated the correlation between RV-PA coupling (TAPSE/PASP, RV-FAC/RVSP, S’/RVSP) and 6-MWD. We also aim to explore the correlation between RV-PA coupling and left ventricular diastolic function (E/A, E/e’, lateral e’, septal e’, peak tricuspid regurgitation velocity, and left atrial volume index).

Method: A cross-sectional study with 39 HFrEF patients was recruited at 108 Central Military Hospital, Vietnam, from 12/2022 to 10/2023. All patients underwent comprehensive evaluation with echocardiography and 6-MWT.

Result: There is a statistically significant difference in the mean TAPSE/PASP ratio between two groups: hypertension and non-hypertension, with values of 0.79 ± 0.25 and 0.59 ± 0.22, respectively (p-value = 0.012). Under univariate and multivariate analysis, there is no correlation between right ventricular-pulmonary artery coupling and 6-MWD, as evidenced by parameters including TAPSE/PASP (r=0.111, β=37.09, p=0.499), RV-FAC/RVSP (r=0.012, β=1.29, p=0.944), and S’/RVSP (r=0.216, β=105, p=0.186). Nevertheless, there is a correlation between RV-FAC/RVSP and S'/RVSP with LAVi, with respective values of (r = -0.522, β = -11.97, p-value = 0.001) and (r = -0.487, β = -0.005, p-value = 0.002).

Conclusion: In our study of 39 HFrEF patients, we observed no correlation between RV-PA coupling parameters (TAPSE/PASP, RV-FAC/RVSP, and S’/RVSP) and 6-MWD. When exploring the relationship of RV-PA coupling with other echocardiographic parameters, RV-FAC/RVSP and S’/RVSP showed correlations with LAVi. This enhances our comprehension of the interaction between RV-PA coupling and left diastolic function, implying a potential clinical use for RV-FAC/RVSP and S’/RVSP in predicting early alterations in left ventricular dynamics.