Introduction

Percutaneous, Transcatheter Aortic Valve Implantation (TAVI) is particularly appealing to Aortic Stenosis (AS) patients with advanced age and comorbidities whose outcome depends on less invasive surgical access and concomitant need of mechanical ventilation cardioplegia and heart-lung-machine [1,2]. Since the landmark PARTNER-trials, this less-invasive method has become an established alternative to conventional surgery in individuals at high surgical risk [3,4]. Meanwhile, several controlled trials and registries confirmed non-inferiority for TAVI in patients at intermediate and low risk as well [5,6]. Whereas beneficial outcome is proven for transfemoral TAVI, little is known about immediate and post-procedural hemodynamic changes compared to patients´ baseline status. This depends on the need of predominantly invasive measurement tools such as Swan-Ganz®- or PICCO® catheterisation systems. Information regarding baseline hemodynamics and changes after procedure may provide important information on TAVI scheduling and outcomes. Moreover, these parameters may offer an accurate tool for tailored peri- and post-procedural management and may influence outcomes of subgroups like patients with Low-Gradient (LG) and Non-Low-Gradient (NLG) AS in a different manner [7,8]. The NICaS® whole body electrical bio-impedance monitoring system provides an accurate and approved method to obtain hemodynamic parameters in an easy non-invasive manner and that can be used bedside at any time for repeated measurements [9-13]. Recently, we could demonstrate an improvement of hemodynamics in an unselected TAVI patients´ collective using the NICaS® system [14]. Nevertheless, this observation was not designed to discriminate changes within different subgroups with aortic valve stenosis. Since there is proven accuracy for illustration of hemodynamic changes in patients measured with the NICaS®, the present prospective series aims to report on the ability to discriminate short-term hemodynamic outcomes in TAVI patients for subgroups with LG- and NLG-AS.

Materials and Methods

Patients

Over a period of 21 months, 100 unselected patients with severe symptomatic AS were scheduled to TAVI procedure after heartteam decision. Endovascular TAVI was applied in local anaesthesia and analgosedation without mechanical ventilation in all patients using the Medtronic Evolut R® (n=48), Edwards Sapien 3® (n=47) or Boston Scientific SYMETIS ACURATE neo™ TF® (n=4) system. All comers were measured with the NICaS® system at baseline at the day before TAVI. Measurements were repeated after six to eight hours at the same day of TAVI procedure at the cardiology Intensive Care Unit (ICU) when patients were free of inotropics vasopressors or sedatives. A second in-hospital follow-up was performed at the day of discharge [mean hospital Length of Stay (LOS) 6.4 ± 1.2 days]. One patient died before onset of TAVI procedure due to lowoutput heart failure and was excluded from analysis. Thus, 99 patients left to be analysed for hemodynamic outcomes at the day of procedure and before discharge. Additionally, the last 48 of the 99 included all-comers were assessed for baseline quality of life (QoL) using the EQ-5D-5L questioner [14,15]. Patients were called by phone to report on clinical outcomes after 3 months.

Ethics committee approval The analysis was approved by the local Ethics Committee complying with the Declaration of Helsinki. All patients gave written informed consent for participation and anonymized data publication. Trial Registration Number 105/18, date of ethical approval 1st of November 2018.