Hypoalbuminaemia and heart failure: A practical review of current evidence

Abstract

Hypoalbuminaemia (serum albumin levels ≤3.5 g/dl) is associated with poor outcomes among patients with heart failure (HF). This narrative review includes original articles and reviews published over the past 20 years and retrieved from PubMed using the following search terms (or their combination): 'heart failure', 'hypoalbuminaemia', 'heart failure with reduced ejection fraction', 'heart failure with preserved ejection fraction', 'all-cause mortality', 'in-hospital mortality', 'hospitalization', 'prognosis'. The aims of this review are to provide an overview on the prevalence of hypoalbuminaemia in HF, its impact on clinical outcomes, and potential mechanisms that may suggest future therapeutic strategies. Hypoalbuminaemia is frequent in HF patients, especially among the elderly. However, data about the exact epidemiology of hypoalbuminaemia are scant due to different definitions, and prevalence is estimated between 5% and 70% across the whole spectrum of ejection fraction. Current evidence points to hypoalbuminaemia as a marker of poor outcomes in HF, irrespective of the ejection fraction, and in other cardiovascular diseases. Among patients who suffered from acute coronary syndrome, those with hypoalbuminaemia had an increased risk of new-onset HF and in-hospital mortality. Albumin, however, might also play a role in the natural history of such diseases due to its antioxidant, anti-inflammatory, and antithrombotic properties. Whether albumin supplementation or nutritional support in general would be beneficial in improving clinical outcomes in HF is not completely clear and should be evaluated in adequately designed studies.

Keywords: Albumin; Heart failure; Hospitalization; Hypoalbuminaemia; Mortality; Prognosis.

Figure 1

Properties and metabolism of albumin. Albumin is the most abundant protein in the body and plays important roles, such as regulation of oncotic pressure and carrier of various compounds. Its metabolism relies on a balance between synthesis and catabolism. Importantly, transcapillary escape rate (TER) – an average of two rates, fast (12%, into the viscera) and slow (2%, into the skin and muscles) – may be increased in case of inflammation, infections, and trauma. TER, transcapillary escape rate. This figure has been partially created using Servier Medical Art templates, which are licensed under a Creative Commons Attribution 3.0 Unported License; https://smart.servier.com.

Figure 2

Predisposing factors to hypoalbuminaemia. Different factors contribute to low levels of serum albumin. Hypoalbuminaemia is more frequently encountered in elderly people and generally increases all‐cause mortality and negatively impacts on heart failure (HF) outcomes. ADHF, acutely decompensated heart failure. This figure has been partially created using Servier Medical Art templates, which are licensed under a Creative Commons Attribution 3.0 Unported License; https://smart.servier.com.