Background: Right ventricular (RV) contractile function and pulmonary artery (PA) pressures influence outcomes in patients with heart failure (HF). Analysis of RV-arterial coupling (RVAC) from pressure-volume loops is not routinely performed. Several non-invasive RVAC methods by echocardiography have been described in patients with HF. The aim of this study was to compare the prognostic impact of these RVAC methods in HF patients.
Methods: One-hundred-sixty patients with chronic HF underwent standard, speckle-tracking (STE) and three-dimensional (3DE) echocardiography. RVAC was assessed by calculating: a) tricuspid annular plane systolic excursion (TAPSE) to noninvasively measured PA systolic pressure ratio (TAPSE/PASP), b) RV free wall longitudinal strain (RVFWLS) by STE to PASP ratio; and c) by 3DE, by measuring PA effective elastance (Ea), RV maximal end-systolic elastance (Emax), and RVAC (PA Ea/RV Emax) using simplified formulas including mean pulmonary artery pressure (mPAP), stroke volume and end-systolic volume. The primary endpoint was a composite of all-cause mortality and/or HF hospitalization.
Results: During a median follow-up time of 17.9 months, 35 events occurred. At univariable analysis, TAPSE/PASP ratio < 0.43 (HR: 4.36 [95%CI: 2.18-8.65, P<0.0001]), RVFWLS/PASP ratio < 0.50 (HR 8.07 [95%CI: 3.12-20.82, P<0.0001]), and 3D-RVAC > 1.13 (HR: 4.34 [95%CI: 1.80-10.46, P<0.0001]) were all significantly associated with outcome. After adjusting for MAGGIC risk score and natriuretic peptides levels at multivariable analysis, TAPSE/PASP ratio was no longer predictive of adverse outcome.
Conclusions: Non-invasively assessed RV-arterial coupling by 3D echocardiography and RV free wall longitudinal strain appears to be a more powerful predictor of outcome in heart failure than traditional index.