Improving Exercise Ability for Patients With Common Type of Heart Failure

Among obese older patients with heart failure and preserved ejection fracture (HFPEF), caloric restriction or aerobic exercise training improved their ability to exercise without having shortness of breath, a new study in JAMA finds. However, neither intervention had a significant effect on exercise intolerance, a major determinant of reduced quality of life (QOL).

HFPEF, the most rapidly increasing form of heart failure, occurs primarily in older women and is associated with high rates of illness, death, and healthcare expenditures. More than 80% of HFPEF patients are obese or overweight.

Dalane W. Kitzman, MD, of Wake Forest University, and colleagues randomly assigned 100 older obese patients with chronic, stable HFPEF to 20 weeks of diet, exercise, diet and exercise, or to a control group. The patients’ exercise capacity (peak oxygen consumption, VO₂) and QOL were measured (Minnesota Living with Heart Failure Questionnaire).

Of the 100 enrolled participants in the trial, 26 were randomized to exercise, 24 to diet, 25 to exercise plus diet, and 25 were controls. Of these, 92 completed the trial.

The researchers found that peak oxygen consumption was increased significantly by both exercise and diet, and the combination of diet with exercise produced an even greater increase in exercise capacity. Change in peak oxygen consumption was positively correlated with the change in percentage of lean body mass. Body weight decreased 7% in the diet group, 3% in the exercise group, and by 10% in the diet plus exercise group; the control group had an only 1% decrease in body weight. There was no significant change in the QOL measurement score with exercise or diet, however.

The researchers concluded that the effects of diet and exercise may be additive.

An editorial accompanying the study, by Nanette K. Wenger, MD, of the Emory University School of Medicine, said the study’s results were intriguing and worthy of further investigation in a community population, with longer follow-up, either with or without specific provision of meals to effect caloric restriction. Dr Wenger said translation of this type of intervention to the community will be challenging.

“Whether nonprofessionally administered diet and nonmedically supervised exercise could safely attain similar benefit is uncertain but worthy of exploration,” she wrote.