Right ventricular-pulmonary arterial coupling in patients with implanted left ventricular assist devices

Abstract

Objective: Both the right ventricular (RV) contractile function and pulmonary arterial (PA) pressure influence clinical outcomes in patients supported with left ventricular assist devices (LVADs), but the impact of RV-PA coupling is unknown. This study aimed to determine the prognostic impact of RV-PA coupling in patients with implanted LVADs.

Methods: Patients with implanted third-generation LVADs were retrospectively enrolled. The RV-PA coupling was assessed preoperatively by the ratio of RV free wall strain (RVFWS) derived from speckle-tracking echocardiography and noninvasively measured peak RV systolic pressure (RVSP). The primary end point was a composite of all-cause mortality or right heart failure (RHF) hospitalization. Secondary end points consisted of all-cause mortality at a 12-month follow-up and RHF hospitalization.

Results: A total of 103 patients were screened, and 72 with good RV myocardial imaging were included. The median age was 57 years; 67 patients (93.1%) were men, and 41 (56,9%) had dilated cardiomyopathy. A receiver-operating characteristic analysis (AUC 0.703, 51.5% sensitivity, 94.9% specificity) was used to identify the optimal cutoff point (0.28%/mmHg) for the RVFWS/TAPSE threshold. Nineteen subjects (26.4%) had advanced RV-PA uncoupling. Event rates were estimated using the Kaplan-Meier method showing a strong association with an increased risk for the primary end point of death or RHF hospitalization (89.47% vs. 30.19%, p < 0.001). A similar observation applied to all-cause mortality (47.37% vs. 13.21%, p = 0.003) and RHF hospitalization (80.43% vs. 20%, p < 0.001).

Conclusions: An advanced RV dysfunction assessed by RV-PA coupling may serve as a predictor of adverse outcomes in patients with implanted LVADs.

Keywords: Chronic heart failure; Left ventricular assist device; Mechanical circulatory support; Speckle-tracking echocardiography; Strain imaging.