Abstract 14928: The Factors Impacting on Resting Energy Expenditure in Refractory Heart Failure Patients and the Probability of Urine Amino Acids Analysis as an Indicator for Calorie Intake Insufficiency

Abstract

Introduction: Cachexia is a critical issue in patients with refractory heart failure (HF). Although the elevation of resting energy expenditure (REE) can progress cachexia through relatively insufficient calorie intake, the detail of REE in HF patients remains uncertain and no useful marker for predicting insufficient calorie intake has been established. This study aimed to assess the REE of HF patients and to evaluate the detectability of serum and urine laboratory markers for insufficient calorie intake. Methods: We measured REE using indirect calorimetry in 69 HF patients (NYHA class II-IV) in our hospital. In 25 out of 69 patients, serum albumin, amino acids, and 24-hour urine amino acids were measured. The calorie intake insufficiency was determined based on measured REE multiplied by activity index Results: As compared to the predicted values by Harris-Benedict equation, 43 patients (63%) had an elevated REE and the mean REE was approximately 4% elevated. There was no significant correlation between the REE and parameters indicating HF severity, including cardiac index on right heart catheterization and BNP level. Only body mass index (BMI) negatively correlated with the REE (r=-0,66, p<0.01). Of 25 patients, 16 (64%) had calorie intake insufficiency. The excreted amount of urine essential amino acids was lower and mostly under normal range, especially significantly decreased in Histidine and Phenylalanine levels in the patients with calorie intake insufficiency compared to those without calorie intake insufficiency, whereas serum levels of albumin and essential amino acids were kept within a normal range in the both. Conclusions: Our findings suggest that the patients with refractory HF, especially having low BMI, are likely to be under inadequate calorie intake due to elevated REE. The calorie intake insufficiency could not be identified with serum levels of albumin nor essential amino acids. Instead, urine essential amino acids would decrease first prior to plasma levels, indicating this measurement would be a useful marker to detect calorie intake insufficiency.