Cardiac Cachexia in Left Ventricular Assist Device Recipients and the Implications of Weight Gain Early After Implantation.

Background Severe cardiac cachexia or malnutrition are commonly considered relative contraindications to left ventricular assist device (LVAD) implantation, but post-LVAD prognosis for patients with cachexia is uncertain. Methods and Results Intermacs (Interagency Registry for Mechanically Assisted Circulatory Support) 2006 to 2017 was queried for the preimplantation variable cachexia/malnutrition. Cox proportional hazards modeling examined the relationship between cachexia and LVAD outcomes. Of 20 332 primary LVAD recipients with available data, 516 (2.54%) were reported to have baseline cachexia and had higher risk baseline characteristics. Cachexia was associated with higher mortality during LVAD support (unadjusted hazard ratio [HR], 1.36 [95% CI, 1.18-1.56]; P<0.0001), persisting after adjustment for baseline characteristics (adjusted HR, 1.23 [95% CI, 1.0-1.42]; P=0.005). Mean weight change at 12 months was +3.9±9.4 kg. Across the cohort, weight gain ≥5% during the first 3 months of LVAD support was associated with lower mortality (unadjusted HR, 0.90 [95% CI, 0.84-0.98]; P=0.012; adjusted HR, 0.89 [95% CI, 0.82-0.97]; P=0.006). Conclusions The proportion of LVAD recipients recognized to have cachexia preimplantation was low at 2.5%. Recognized cachexia was independently associated with higher mortality during LVAD support. Early weight gain ≥5% was independently associated with lower mortality during subsequent LVAD support.

Skeletal Muscle Mass Recovery Early After Left Ventricular Assist Device Implantation in Patients With Advanced Systolic Heart Failure.

BACKGROUND: Patients with advanced systolic heart failure are at risk of unintentional weight loss and muscle wasting. It has been observed that left ventricular assist device (LVAD) recipients gain weight after device implantation, although it is unknown whether this represents skeletal muscle mass gains. We aimed to determine whether skeletal muscle mass increases early during LVAD support. METHODS: We prospectively recruited 30 adults with systolic heart failure ±21 days from LVAD implantation. Participants underwent whole-body dual X-ray absorptiometry to measure fat free mass, appendicular lean mass (ALM, lean mass in the arms and legs) and fat mass. Dual X-ray absorptiometry imaging was repeated at 3 and 6 months after LVAD implantation, with participation ending after the 6-month visit or heart transplantation, whichever occurred first. Changes in body composition were evaluated using mixed effects linear regression models. RESULTS: The cohort was 87% male, with mean age 56±12 (SD) years, and mean body mass index 26.4±5.4 kg/m2. Per sarcopenia ALM criteria, 52% of participants had muscle wasting at baseline. At baseline, mean fat free mass and ALM were 56.4±11.7 and 21.0±5.3 kg, respectively. Both measures increased significantly (P<0.001) over 6 months of LVAD support: mean fat free mass change at 3 and 6 months: 2.3 kg (95% CI, 1.0-3.5) and 4.2 kg (95% CI, 2.2-6.1); mean ALM change at 3 and 6 months: 1.5 kg (95% CI, 0.7-2.3) and 2.3 kg (95% CI, 0.9-3.6). CONCLUSIONS: Among LVAD recipients with advanced systolic heart failure and high baseline prevalence of muscle wasting, there were significant gains in skeletal muscle mass, as represented by dual X-ray absorptiometry fat free mass and ALM, over the first 6 months of LVAD support.

Functionalized Electrospun Poly(Vinyl Alcohol) Nanofibrous Membranes with Poly(Methyl Vinyl Ether-Alt-Maleic Anhydride) for Protein Adsorption.

In this work, electrospun poly(vinyl alcohol) (PVA) nanofiber membranes were functionalized by incorporating poly(methyl vinyl ether-alt-maleic anhydride) (poly(MVE/MA), PMA) for the selective adsorption of proteins. The capture performance was regulated by an optimizing buffer pH, PMA content, and protein concentration. Lysozyme was used as the model protein and a high adsorption capacity of 476.53 ± 19.48 was obtained at pH 6, owing to the electrostatic attraction between the negatively charged nanofibers and positively charged proteins. The large specific surface area, highly open porous structure, and abundant available carboxyl groups contributed to such high adsorption performance. Moreover, the nanofiber membranes exhibited good reusability and good selectivity for positively charged proteins. The obtained results can provide a promising method for the purification of proteins in small analytic devices.

Direct characterization of cotton fabrics treated with di-epoxide by nuclear magnetic resonance.

A non-acid-based, di-functional epoxide, neopentyl glycol diglycidyl ether (NPGDGE), was used to modify cotton fabrics. Direct characterization of the modified cotton was conducted by Nuclear Magnetic Resonance (NMR) without grinding the fabric into a fine powder. NaOH and MgBr2 were compared in catalyzing the reaction between the epoxide groups of NPGDGE and the hydroxyl groups of cellulose. Possible reaction routes were discussed. Scanning electron microscopy (SEM) images showed that while the MgBr2-catalyzed reaction resulted in self-polymerization of NPGDGE, the NaOH-catalyzed reaction did not. Fourier transform infrared spectroscopy (FTIR) showed that at high NaOH concentration cellulose restructures from allomorph I to II. NMR studies verified the incorporation of NPGDGE into cotton fabrics with a clear NMR signal, and confirmed that at higher NaOH concentration the efficiency of grafting of NPGDGE was increased. This demonstrates that use of solid state NMR directly on woven fabric samples can simultaneously characterize chemical modification and crystalline polymorph of cotton. No loss of tensile strength was observed for cotton fabrics modified with NPGDGE.