Patients with heart failure are at an increased risk for TD, for many reasons such as malnutrition, anorexia and the use of diuretic drugs, such as furosemide. Several studies have demonstrated a high prevalence of TD in hospitalized patients with heart failure, ranging from 13 % to 91% depending on the population studied. This wide variation is due to differences in the underlying nutrition status of subjects, the concurrent use of medications including loop diuretics, the severity of disease, and the measurement technique used for the assessment of thiamin status. These studies however, while clinically important, are limited by their small sample size and indirect measurement of thiamin status. Also, these studies have focused exclusively on the hospitalized patients, whereas ambulatory HF patients have received little attention.