639 Direct Comparison of the Performance Characteristics of the Thoratec HeartMate II, Heartware HVAD and Jarvik 2000 Left Ventricular Assist Devices

Abstract

stage HF (mean CI 1.5 0.3 l/min/m) at the time of HMII implantation. Tissue was snap frozen at -80°C. After fixation, sections were incubated overnight with primary rabbit NET antibody at 1:100 concentrations. Biotinylated secondary antibody at 4°C against rabbit IgG was applied. Avidin-biotin peroxidase complex was used to label the secondary antibody. The perioxidase was developed using nickel-enhanced diaminobenzidine to produce different colorimetric layers. Images were captured digitally and analysed by two independent observes using analySIS software. NET immunoreactivity was calculated as the average percentage area covered from randomly selected 5 different regions. Results: 16 patients (14 males) were studied. 11 had recovered and had their LVAD explanted. Intraclass correlation coefficient between both observers revealed moderate reliability of 45.8% (R 0.464, P 0.028).Percentage NET immunoreactive nerve fibers per area were significantly higher in recovered patients at the time of implantation (1.04 0.30% vs 0.65 0.43%, P 0.05). There was a moderate correlation between NET immunoreactive nerve fibers and myocardial recovery (R 0.512, P 0.035). Conclusions: Patients recovered with LVAD support had higher percentage of NET immunoreactive nerve fibers per total area in the LV apex at the time of implantation. Immunostaining evaluation of NET immunoreactive nerve fibers may predict myocardial recovery.