Poehlman and colleagues' paper [1] about increased resting metabolic rate in patients with congestive heart failure addresses a common practical problem. The authors found that the resting metabolic rate was at least 18% higher in the patients than in the controls. This resting hypermetabolism occurs in response to increases in respiration and cardiac muscle work, which are a consequence of a reduced cardiac output. Thus, the metabolic rate is likely to vary among patients with congestive heart failure depending on the level of cardiac decompensation (that is, between patients with class II and those with class IV disease [New York Heart Association]). Therefore, we think that patients in the heart failure group should be substratified by their calculated cardiac outputs and then that the resting metabolic rate should be ascribed to different ranges of output. This would be particularly important in elderly patients with cardiac failure in whom caloric needs are often underestimated.

Although resting hypermetabolism further magnifies the reduction in net available energy [2], the ingestion of meals and the active transport of nutrients also require energy. Thus, in elderly persons with heart failure, it would be advisable to adjust the resting metabolic rate for the cardiac output before calculating the recommended caloric intake. Otherwise, the use of a cumulative number for the whole group could result in further compromise of ventricular function or in inadequate nutrition [3], depending on whether a patient has class II or class IV disease.