Association between aortic valve opening during exercise and right ventricular reserve in patients with left ventricular assist device

Abstract

Abstract Background Aortic valve (AV) opening in patients after left ventricular (LV) assist device (LVAD) implantation is important to prevent adverse events. We hypothesised that right ventricular (RV) reserve function would play a crucial role to overcome pulmonary vascular resistance to ensure LV filling and AV opening in LVAD patients. However, detailed analysis between RV haemodynamic exercise response and AV opening with recent LVAD patients remains relatively unknown. Purpose The aim of this study was to explore the haemodynamic parameters observed during rest and maximal exercise and investigate the association of AV opening with RV reserve function and adverse events in patients with LVAD. Methods We prospectively examined 22 consecutive LVAD patients who were admitted to our university hospital between June 2020 and December 2022 after excluding those who were unable to perform exercise (n = 8). All patients underwent invasive exercise right heart catheterisation with simultaneous echocardiography in the supine position. AV status was assessed at rest and during exercise. RV stroke work index (RVSWI) was calculated as 0.0136 × stroke volume index × (mean pulmonary artery pressure – right atrial pressure) at rest and during exercise. RVSWI change from rest to peak exercise (ΔRVSWI) were calculated to evaluate RV reserve function. The patients were divided into three groups according to AV opening both rest and exercise (n = 6), AV opening only during exercise (n = 7), and AV closed both rest and exercise (n = 9). Results Patients were predominantly male (77%) and the median age was 51 (interquartile range [IQR] 39-63) years. There were no significant differences in age, sex, primary aetiology of heart failure, type of LVAD devices or echocardiographic parameters and RVSWI at rest among the groups. Patients with AV opening both rest and exercise, and only during exercise had significantly higher ΔRVSWI than those with AV closed both rest and exercise (Figure A). During a median follow-up period of 433 (IQR 228-558) days, adverse events occurred in six patients (27%), including one death, one hospitalisation for major bleeding, and four hospitalisations for right heart failure. Kaplan–Meier analysis revealed that the adverse events more frequently occurred in patients with AV closed both rest and exercise compared to those with AV opening (p = 0.014) (Figure B). Conclusions In patients with LVAD, AV opening at rest or during exercise was associated with preserved RV reserve function and less adverse events. These findings suggest that the observation of the AV opening during exercise would be useful for early identification of high-risk patients with LVAD. Further studies are needed to confirm our findings.