Serum Protein Levels as Biomarkers of Muscle Strength in Patients with End-Stage Systolic Heart Failure

Abstract

Purpose Patients with heart failure (HF) are at increased risk of unintentional weight loss, principally loss of skeletal muscle mass, which may exacerbate patients’ impairments in physical functioning. Serum protein levels have been proposed as biomarkers of cardiac cachexia based upon their purported relationship with protein balance and nutritional status. However, it is not known whether the serum protein markers albumin and prealbumin are related to muscle strength and dietary protein intake in patients with HF. Methods We retrospectively analyzed a dataset prospectively collected between 5/2016-3/2020 from patients with end-stage systolic HF ±21 days from left ventricular (LVAD) implantation. Each visit included venous blood draw for serum albumin and prealbumin levels, hydraulic hand dynamometer for handgrip strength and dietary protein intake collection for 3 days followed by analysis in the Food Processor® software. All data collection was repeated at 3 and 6 months after LVAD implantation (±14 days), with study participation ending after either the 6 month visit or heart transplantation, whichever occurred first. Pearson correlations and linear mixed effects models were constructed using SAS and adjusted for 24-hour averaged protein intake. Results The cohort was 89.7% (35/39) male, with mean age 57±11.6 years. There was a positive correlation between baseline albumin levels and baseline handgrip strength (r=0.48, p=0.002, n=38), but no correlation between baseline prealbumin levels and handgrip strength (r=0.01, p=0.94, n=38). There was a positive association across all data for albumin and handgrip strength (n=90 values, p Conclusion In patients with HF undergoing left ventricular assist device (LVAD) evaluation, serum albumin levels could be used as a biomarker of muscle strength, independent of the dietary protein intake. Serum albumin and prealbumin levels do change over the medium-term, showing a stepwise increase at 3 and 6 months of LVAD support, with the greatest increase during the first 3 months.