Echocardiographic Assessment of Right Ventriculo-arterial Coupling: Clinical Correlates and Prognostic Impact in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy

Abstract

Background: Right ventriculo-arterial coupling (RV-PA) can be estimated by echocardiography using the ratio between tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP) and it has prognostic value in the general heart failure (HF) population. We aimed to study the clinical correlates and prognostic value of RV-PA in HF patients undergoing cardiac resynchronization therapy (CRT).

Methods: We retrospectively studied 70 HF patients undergoing CRT implantation.

Results: RV-PA coupling was estimated by TAPSE/PASP ratio using baseline echocardiography. Non-response to CRT was defined as improvement of left ventricular ejection fraction < 5% in a follow-up echo 6-12 months after CRT. Those with lower TAPSE/PASP ratios (worse RV-PA coupling) had higher NT-proBNP concentrations and increased E/e' ratio. TAPSE/PASP ratio and PASP, but not TAPSE, predicted nonresponse to CRT with TAPSE/PASP ratio showing the best discriminative ability with a sensitivity of 76% and specificity of 71%. Among these parameters, PASP independently predicted all-cause mortality.

Conclusions: RV-PA coupling estimated by TAPSE/PASP ratio was associated with established prognostic markers in HF. It numerically outperformed PASP and TAPSE in predicting the response to CRT. Our data suggest that this simple and widely available echocardiographic parameter conveys significant pathophysiological and prognostic meaning in HF patients undergoing CRT.

Keywords: Cardiac resynchronization therapy; Heart failure; Pulmonary circulation; Right ventricle function; Right ventriculo-arterial coupling.

Figure 1. Criteria for patient inclusion and exclusion in this retrospective observational study. CRT: cardiac resynchronization therapy, EACVI: European Association of Cardiovascular Imaging.

Figure 2. Pearson's correlation analysis between TAPSE/PASP and log-transformed NT-proBNP before cardiac resynchronization therapy. Solid line represents its linear relationship, with 95% confidence interval limited by dashed lines. p < 0.05 was considered significant. NT-proBNP: N-terminal pro-B-type natriuretic peptide, PASP: pulmonary artery systolic pressure, TAPSE: tricuspid annular plane systolic excursion.

Figure 3. Percentage of patients with improved LVEF response by baseline PASP, TAPSE and TAPSE/PASP (categorized by median) during maximum follow-up period after CRT. Patients with an increase of LVEF ≥ 5% after CRT were considered to have an improved response. Small inset indicates median values for the variables presented. Number of patients that showed improved LVEF is indicated inside bars. p-values were calculated with use of the chi-square test. ^*p < 0.05 was considered significant. CRT: cardiac resynchronization therapy, LVEF: left ventricular ejection fraction, ns: not-significant, PASP: pulmonary artery systolic pressure, TAPSE: tricuspid annular plane systolic excursion.

Figure 4. ROC curves for baseline TAPSE, PASP and TAPSE/PASP to identify unimproved LVEF (defined as Δ LVEF < 5%) after CRT. AUC: area under the curve, CI: confidence interval, LVEF: left ventricular ejection fraction, PASP: pulmonary artery systolic pressure, ROC: Receiver operator characteristic, TAPSE: tricuspid annular plane systolic excursion. p < 0.05 was considered significantly different from dotted line (AUC = 0.5).