Measurements of malnutrition offer incremental prognostic value for patients with heart failure, but more work is needed to tease out which components of the condition are most crucial to calculate and treat, researchers reported in JACC: Heart Failure.
Lead author Shirley Sze, MBBS, and colleagues studied 3,386 patients with confirmed heart failure from a single center in the United Kingdom. The median age of the population was 75 and 61 percent of the patients were men.
About half of the participants died over a median follow-up of 4.3 years, with three different malnutrition scores each improving the mortality risk prediction of an existing clinical model.
However, there was wide variation in the proportion of patients the models classified as malnourished, ranging from 8 percent to 54 percent. But when considering only patients who were moderately to severely malnourished, the three models were more aligned—ranging from 6.7 percent to 10 percent.
A base model including age, urea, N-terminal pro-B-type natriuretic peptide (NT-proBNP), gender and New York Heart Association functional class, among other factors, achieved a C-statistic of 0.719 for mortality. All three models boosted the predictive value, with the geriatric nutritional risk index (GNRI) improving it the most (C-statistic of 0.724).
GNRI was the only tool among the three that were studied that included both the ratio of body weight to height as well as a serum biomarker (albumin level). The other two scores only used serum markers.
“Although we found that indices of malnutrition increased the prognostic value of the models we constructed, the modest increase in CI (concordance index) is of little value for the individual patient,” Sze et al. wrote. “Given the effect in a substantial population of patients, however, the increase in C-statistic does emphasize that there is some component of ‘malnutrition’ that is related to prognosis above and beyond the usual clinical variables taken into account when constructing prognostic models. In turn, that statistical result suggests that there may be some value in exploring malnutrition, and, perhaps, its treatment, further.”
Heart failure can lead to loss of appetite, which in turn can contribute to cachexia—or “wasting syndrome”—which has a poor prognosis. The researchers found their nutritional measures were more predictive of mortality than body mass index (BMI) alone, suggesting BMI shouldn’t be used as a “surrogate” for nutritional status.
“Screening for malnutrition using the most appropriate tool for patients with HF might enable early identification and characterization of patients at risk of developing cachexia,” the authors wrote. “Future studies should focus on studying whether better use of available treatments or novel treatments might improve nutritional status and eventually outcomes in these at-risk patients with HF.”