Assessment and Prognostic Impact of Right Ventricular Function in Patients with Pulmonary Arterial Hypertension Undergoing Pulmonary Artery Denervation: Central Role of Global Right Ventricular Longitudinal Peak Systolic Strain

Abstract

ABSTRACTBackground: Echocardiographic right ventricular (RV) functional parameters and longitudinal peak systolic strain (LS) are important determinants of prognosis in patients with pulmonary arterial hypertension (PAH). Pulmonary artery denervation (PADN) has been shown to reduce pulmonary artery pressures (PAP) in PAH. Whether this results in improved RV function is unknown. We therefore sought to evaluate serial changes in RV function and clinical outcomes after PADN, and determine the role of baseline RV-LS as a prognostic tool.Methods: Between March 2014 and March 2016, 40 patients with PAH who underwent PADN were studied. RV function was evaluated at baseline, 1 week, 3 months, 6 months, and >1 year after PADN, and correlations between RV-LS, RV functional parameters, 6-minute walk distance (6MWD), and pulmonary vessel resistance (PVR) were examined. Receiver operating characteristic curve analysis was used to determine the optimal baseline RV-LS cutoff value to predict PADN responder status, and prognosis was assessed in these groups.Results: PADN resulted in sustained changes in PVR and RV-LS over time (mean follow-up of 763 ± 254 days). By multivariate analysis, baseline RV-LS was the only independent predictor of ∆mPAP (β = −0.736, p = 0.001) and ∆PVR (β = −0.076, p = 0.03), and significantly correlated with 6MWD (r = −0.586, p < 0.001) at the end of follow-up. Baseline RV-LS ≥ −11.3% had a sensitivity of 78.1% and a specificity of 75.0% for predicting non-responders to PADN. During follow-up there were 10 (25%) PAH-related events, including 4 (10%) cardiac deaths. PAH-related events after PADN were more frequent in patients with RV-LS ≥ −11.3% vs. < −11.3% (46.2% vs. 14.8%, p = 0.03).Conclusions: PADN results in sustained improvements in PVR and RV-LS. Baseline RV-LS is the strongest predictor of improved hemodynamic measures after PADN in patients with PAH, and is strongly associated with late 6MWD and prognosis. Specifically, baseline RV-LS ≥ −11.3% predicts non-responder status and PAH-related events after PADN, and thus may be useful to identify which PAH patients may benefit from the PADN procedure.