Simple malnutrition scores predict mortality in HF
Prevalence and Prognostic Significance of Malnutrition Using 3 Scoring Systems Among Outpatients With Heart Failure. A Comparison With Body Mass Index
Introduction and methods
There are 3 malnutrition scores that have been studied in HF [1-4]:
- The controlling nutritional status (CONUT) index determined on the basis of serum albumin, total cholesterol levels, and total lymphocyte counts ,
- The prognostic nutritional index (PNI) calculated by BMI and serum albumin value.
- The geriatric nutritional risk index (GNRI) requiring the serum albumin level and lymphocyte count.
There are data showing that each score identifies HF patients with various degrees of malnutrition, and that they predict outcomes, but it is not clear, whether the diagnostic rate of malnutrition and the predictive prognostic ability of the 3 scores differ.
In this study, the prevalence and prognostic importance of malnutrition was investigated, using the 3 different scores, in a large cohort of ambulatory HF patients referred to a specialized clinic between 2000 and 2016. The primary endpoint was all-cause mortality.
- Out of the 4,021 patients enrolled, 3,386 had HF, and out of all HF patients, 35% had a left ventricular ejection fraction (LVEF) <40%, and 30% had a New York Heart Association functional class III-IV.
- By GNRI and CONUT scores, 316 (9%) and 1,486 (44%) patients with HF had mild malnutrition, respectively (PNI has no mild category for malnutrition). By GNRI, CONUT, and PNI calculations, 228 (7%), 339 (10%), and 255 (8%) patients had moderate to severe malnutrition, respectively.
- Compared with those with normal nutritional status, patients with malnutrition measured by any of the 3 malnutrition scores were older, more likely to be men, had lower body mass index (BMI), worse symptoms and renal function, and were also more likely to have atrial fibrillation, anemia, and reduced mobility.
- The HRs for all-cause mortality in HF patients with severe malnutrition by different nutritional indices were: CONUT HR: 9.4; 95%CI: 5.9-15.1; GNRI HR: 6.1; 95%CI: 4.5-8.4; PNI HR: 3.0; 95%CI: 2.4-3.7 (all P values <0.001). The association of malnutrition with poor prognosis was regardless of LVEF, NT-proBNP levels, or BMI.
- The nutritional indices improved the prediction of 1-year survival from 0.719 to 0.724 (P<0.001), but BMI did not.
Moderate and severe malnutrition in HF patients, assessed with simple malnutrition scores, is associated with higher all-cause mortality, compared with HF patients without, or with mild malnutrition. Simple malnutrition scores were more closely related to outcome than BMI and the authors therefore conclude that BMI should not be used as surrogate of nutritional status in HF patients.
In their editorial article, Kinugawa and Fukushima  discuss the limitations of the results of Sze et al, which include the single malnutrition assessment during the study, as well as the fact that the 3 indices used, might not reflect the true nutritional status in HF, as would have been the case with the validated and comprehensive Subjective Global Assessment or the Mini Nutritional Assessment. The authors conclude: ‘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.’