Associations between in‐hospital daily protein intake and adverse clinical outcomes in older patients with heart failure

Abstract

Abstract Aims The adverse effects of low daily protein intake (DPI) on clinical outcomes in patients with heart failure (HF) are known; however, an optimal DPI to predict event adverse outcomes remains undetermined. Moreover, whether protein restriction therapy for chronic kidney disease is applicable in patients with HF and renal dysfunction remains unclear. Methods and results In this single‐centre, ambispective cohort study, we included 405 patients with HF aged ≥65 years (mean age, 78.6 ± 7.5 years; 50% women). DPI was estimated from consumption over three consecutive days before discharge and normalized relative to the ideal body weight [IBW, 22 kg/m2 × height (m)2]. The primary outcome was a composite of all‐cause mortality and HF‐related readmission within the 2 year post‐discharge period. Results During an average follow‐up period of 1.49 ± 0.74 years, 100 patients experienced composite events. Kaplan–Meier survival curves revealed a significantly lower composite event‐free rate in patients within the lowest quartile of DPI than in the upper quartiles (log‐rank test, P = 0.02). A multivariate Cox proportional hazards analysis after adjusting for established prognostic markers and non‐proteogenic energy intake revealed that patients in the lowest DPI quartile faced a two‐fold higher risk of composite events than those in the highest quartile [hazard ratio (HR), 2.03; 95% confidence interval (CI), 1.08–3.82; P = 0.03]. The composite event risk linearly increased as DPI decreased (P for nonlinearity = 0.90), with each standard deviation (0.26 g/kg IBW/day) decrease in DPI associated with a 32% increase in composite event risk (HR, 1.32; 95% CI, 1.10–1.71; P = 0.04). There was significant heterogeneity in the effect of DPI, with the possible disadvantage of lower DPI in patients with HF with cystatin C‐based estimated glomerular filtration rate 1.12 g/kg IBW/day in older patients with HF. Caution is warranted when protein restriction therapy is administered to older patients with HF and renal dysfunction.

Keywords

• Heart failure
• Nutrition
• Protein intake
• Mortality
• Hospitalization
• Older patients