BACKGROUND & AIMS: Nutritional assessment may help to explain the incompletely understood obesity paradox in patients with heart failure (HF). Currently, obesity is usually identified by body mass index (BMI). Our objective was to assess the prognostic influence of undernourishment in HF outpatients.

METHODS

Two published definitions of undernourishment were used to assess 214 ambulatory HF patients. Definition 1 included albumin, total lymphocyte count, tricipital skinfold (TS), subscapular skinfold, and arm muscle circumference (AMC) measurements (≥2 below normal considered undernourishment). Definition 2 included TS, AMC, and albumin (≥1 below normal considered undernourishment). Patients were also stratified by BMI and body fat percentage and followed for 2 years. All-cause death or HF hospitalization was the primary endpoint.

RESULTS

Based on BMI strata, among underweight patients, 60% and 100% were undernourished by Definitions 1 and 2, respectively (31% and 44% among normal-weight, 4% and 11% among overweight, and 0% and 3% among obese patients, respectively, according to the two definitions). The most prevalent undernourishment type was marasmus-like (18% of the total cohort). Undernourishment by both definitions was significantly associated with lower event-free survival. Following multivariable analysis, age, NYHA functional class, NTproBNP, and undernourishment (hazard ratio [HR] 2.25 [1.11-4.56] and 2.24 [1.19-4.21] for Definitions 1 and 2, respectively) remained in the model. In this cohort, BMI and percentage of body fat did not independently predict 2-year event-free survival.

CONCLUSIONS

Nutritional status is a key prognostic factor in HF above and beyond BMI and percentage of body fat. Patients in normal BMI range and even in overweight and obese groups showed undernourishment. The high mortality observed in undernourishment, infrequent in high BMI patients, may help to partly explain the obesity paradox. Proper undernourishment assessment should become routine in patients with HF.