Author + information
- Published online May 28, 2018.
- Shintaro Kinugawa, MD, PhD∗ ( and )
- Arata Fukushima, MD, PhD
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
- ↵∗Address for correspondence:
Dr. Shintaro Kinugawa, Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan.
Malnutrition is commonly prevalent in patients with heart failure (HF). Along with the aging society, the number of patients with HF has projected to grow, and such older patients are prone to develop malnutrition with low activity of daily living, sarcopenia, and cognitive impairment, namely, frailty. Malnutrition is triggered by multiple factors such as anorexia, malabsorption secondary to intestinal edema, high energy demand, and cytokine-induced hypercatabolism. To assess such a condition, body weight or body mass index (BMI) has been widely used. Indeed, a significant weight loss is considered to represent progression of cardiac cachexia, which is a catabolic wasting state, and once it develops, its prognosis is known to be devastating. Other surrogate markers, including serum albumin or prealbumin levels and lymphocyte counts, have been shown to reflect nutritional status and are associated with poor prognosis (1). However, because these markers are likely to be influenced by the dilution caused by fluid retention associated with HF, a single parameter is suboptimal to evaluate a patient’s precise nutritional status.
Recently, 3 screening tools have been used in the integral and objective assessment of nutritional status in HF. The Controlling Nutritional Status (CONUT) scores, determined on the basis of serum albumin, total cholesterol levels, and total lymphocyte counts, are in agreement with established nutritional scoring using the Subjective Global Assessment (SGA) (2). The Geriatric Nutritional Risk Index (GNRI) was developed for older persons from the Nutritional Risk Index (NRI) and is calculated by BMI and serum albumin value (3). The Prognostic Nutritional Index (PNI), requiring the serum albumin level and lymphocyte count, was first used for cirrhotic patients and is now widely applied for objective indexes of nutrition state (4). Although all 3 nutritional tools have been shown to predict adverse outcomes in patients with acute and chronic HF (5), it remains unclarified how the diagnostic rate of malnutrition and the predictive prognostic ability are different according to these scoring methods in large-scale HF groups.
In this issue of JACC: Heart Failure, Sze et al. (6) investigated the prevalence of malnutrition and its prognostic importance in 3,386 ambulatory patients with HF and in 635 non-HF patients by using CONUT, PNI, and GNRI. The authors demonstrated that malnutrition determined on the basis of at least 1 nutritional score is frequently observed in 57% of patients with HF. This included 9% with GNRI, 8% with PNI, and 44% with the CONUT score, whereas only 5% of patients were identified as malnourished with all 3 indices. One cause of this different prevalence can be explained by the component factor of each nutritional score. The CONUT score includes total cholesterol level, which is likely to be influenced by comorbid dyslipidemia and statin use. In the present study, more than 50% of patients had been taking a statin, and, therefore, the CONUT score may not be suitable because of the overestimation of malnutrition. Nevertheless, the CONUT score, as well as the GNRI and PNI, revealed the incremental prognostic value of the established risk factors of HF, thus highlighting the importance of nutritional assessment from a different perspective.
Notably, Sze et al. (6) clarified that the characteristics of patients with malnutrition by using any nutritional indices are older and male patients having low BMI, high New York Heart Association functional class, anemia, renal dysfunction, atrial fibrillation, and reduced mobility. This clearly indicates the clinical feature of frailty in older patients with HF, suggesting that malnutrition is closely linked to the process of the frailty cycle. When patients were divided according to left ventricular ejection fraction (EF), patients with reduced ejection fraction (HFrEF) and those with preserved ejection fraction (HFpEF) were equally malnourished according to the CONUT score and PNI, whereas malnutrition defined by GNRI was more common in HFrEF. These results may implicate the need to distinguish among the 3 nutritional indices depending on the phenotype of HF caused by EF. It is also noteworthy that malnutrition was found not only in underweight patients with HF but also in overweight patients.
Although the GNRI, PNI, and CONUT scores each identified the malnourished patients with HF who have worse clinical outcomes, the GNRI showed the greatest incremental value in predicting mortality. This finding suggests that the combination of serum albumin, which is an objective value reflecting a protein reserve, and BMI, a body composition calculation used as a conventional surrogate for nutritional status, is a superior nutritional index for the prediction of clinical outcomes. Furthermore, this may remind us of the relevance of including BMI in assessing nutritional status.
The findings of this study could have a significant practical impact on nutritional assessment for HF; however, several limitations must be noted. What is nutritional status in HF? Essentially, this is a problem. The best indicator should directly reflect the intervention method. Three existing indicators are simple to combine general indicators and effective in estimating prognosis for HF, but it is necessary to verify whether true nutritional status is reflected. The validity of the nutritional status evaluated by simple screening tools remains undetermined because of the lack of comparison with comprehensive nutritional assessment, such as the SGA and Mini Nutritional Assessment (MNA). Given that the nutritional evaluation was conducted only in a single time point, it remains unknown what percentage of patients in this cohort ultimately would have had cardiac cachexia or frailty.
In conclusion, malnutrition defined by simple nutritional screenings is prevalent in outpatients with HF and provides a critical clue for stratifying patients with high mortality. Further research is warranted to verify whether nutrition-oriented management and intervention could reduce mortality and improve quality of life in patients with HF living in the era of an aging society.
↵∗ Editorials published in JACC: Heart Failure reflect the views of the authors and do not necessarily represent the views of JACC: Heart Failure or the American College of Cardiology.
Both authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2018 American College of Cardiology Foundation
- Lourenco P.,
- Silva S.,
- Frioes F.,
- et al.
- Kinugasa Y.,
- Kato M.,
- Sugihara S.,
- et al.
- Lin H.,
- Zhang H.,
- Lin Z.,
- Li X.,
- Kong X.,
- Sun G.
- Sze S.,
- Pellicori P.,
- Kazmi S.,
- et al.