Heartware hvad

Indications for LVAD implantation were determined based on the European Association for Cardio-Thoracic Surgery guidelines. In this study, 3 therapy concepts were categorized: ‘bridge to transplant’, ‘bridge to candidacy’ and ‘destination therapy’. In 68 patients (30.4%), the LVAD was implanted via less-invasive (LIS) approach. We implanted 3 different devices: HeartWare HVAD (Medtronic, Minneapolis, MN), Heartmate (HM) 2 (Abbott, Inc., Chicago, IL, USA) and HM 3. Combined operations were performed in 25 patients: aortic valve replacement (AVR, n = 6); atrial septum defect (ASD) closure (n = 5); left atrial appendage (LAA) closure (n = 6); AVR + LAA closure (n = 1); AVR + tricuspid valve repair (TVR, n = 1); ASD closure + LAA closure (n = 1); ASD closure + TVR (n = 1); TVR + mitral valve repair (n = 1); TVR + mitral valve replacement (n = 1); left ventricular thrombectomy (n = 1); and coronary artery bypass grafting (n = 1).

We used LVAD‐specific IPD data from the quality of life (QoL) questionnaires collected during contemporary HeartWare HVAD (Medtronic, Minneapolis, USA) trials to calculate the utilities (Table 2). For the LVAD arm, the ‘Living with LVAD’ utility was calculated as the mean value across all available time points from patients with no major AEs from the ENDURANCE and the ENDURANCE Supplemental EQ‐5D‐3L and 5L questionnaires.²³, ³¹ We estimated the utility decrements for the AEs included in the model using the ADVANCE BTT + CAP (EQ‐5D‐3L),³² the ENDURANCE (EQ‐5D‐3L), and the ENDURANCE Supplemental (EQ‐5D‐5L) questionnaires.²³, ³¹ We used the average of the before–after score difference by patient as decrements. We estimated the ‘Living on MM’ utility based on the pre‐implant measurement of the ENDURANCE and ENDURANCE Supplemental Trials.²³, ³¹ All the utilities were converted to reflect UK QoL values using the Dolan 1997 algorithm.³³

The left heart (LH) and the pump of an LVAD patient (male, 75 years, BMI: 32.7 kg/m² Intermacs level: 4) suffering from dilated cardiomyopathy was segmented at end systole from computed tomography (CT) images using Mimics Research 20.0 and 3-matics Research 13.0 (Materialise, Belgium NV), including the structures of the left atrium (volume 250 ml) and left ventricle (volume 264 ml). The image segmentation and preparation post-processing of the geometry was performed under the guidance and supervision of a radiologist.
For the first simulation, a 30 mm diameter cylinder that served as a simplified representation of the LA geometry (Figure 1(a)) was attached to the LV, constituting the typical approach used in previous CFD studies for LVAD patients.^{13 (link),14 (link),18 (link),19 (link)} The size of the cylinder (30 mm) corresponds to the size of the mitral annulus deriving from CT-scan and placed in the position of the mitral valve which also derived from CT data. In the second simulation, the anatomical LA was included (Figure 1(b)). The geometry of the HeartWare HVAD (Medtronic, Minneapolis, MN) inflow cannula was considered in this study and it was placed into the model in ANSYS, SpaceClaim (Ansys 19.1, Pennsylvania, USA). In order to have the most realistic scenario for inflow cannula placement, position, and direction of the inflow cannula was derived from CT scans.