Heart failure with preserved ejection fraction (a measure of how well the left ventricle of the heart pumps with each contraction) is the most rapidly increasing form of heart failure, occurs primarily in older women, and is associated with high rates of illness, death, and health care expenditures. More than 80 percent of patients with heart failure with preserved ejection fraction (HFPEF) are overweight or obese. Exercise intolerance is the primary symptom of chronic HFPEF and a major determinant of reduced quality of life (QOL).
Dalane W. Kitzman, M.D., of the Wake Forest School of Medicine, Winston-Salem, N.C., and colleagues randomly assigned 100 older obese participants (average age, 67 years) with chronic, stable HFPEF to 20 weeks of diet, exercise, or both, or a control group. The researchers measured exercise capacity (peak oxygen consumption [Vo2]) and QOL (with the Minnesota Living with Heart Failure Questionnaire; MLHF).
Of the study participants, 26 were assigned to exercise; 24 to diet; 25 to exercise + diet; 25 to control. Of these, 92 completed the trial. The authors found that peak Vo2 was increased significantly by both exercise and diet, and the combination of diet with exercise produced an even greater increase in exercise capacity. The change in peak Vo2 was positively correlated with the change in percent lean body mass. Body weight decreased by 7 percent in the diet group, 3 percent in the exercise group, 10 percent in the exercise + diet group, and 1 percent in the control group.
There was no significant change in the MLHF score with exercise or diet.
The researchers note that because of the reported “heart failure obesity paradox” (lower mortality observed in overweight or obese individuals), before diet can be recommended for obese patients with HFPEF, further studies likely are needed to determine whether these favorable changes are associated with reduced clinical events.
(doi:10.1001/jama.2015.17346; Available pre-embargo to the media at http:/media.jamanetwork.com)