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Lifestyle interventions improved exercise capacity for obese older patients with clinically stable heart failure with preserved ejection fraction (HFpEF) but that benefit didn't translate to better quality of life, a randomized trial showed.

with both a supervised walking intervention and with a reduced calorie lab-provided diet versus controls (1.2 and 1.3 mL/kg body mass/min, respectively, both P<0.001),, of Wake Forest School of Medicine in Winston Salem, N.C., and colleagues found.

The two interventions had an additive effect together for a "robust" 2.5 mL/kg/min improvement in VO₂ that well exceeded the clinically meaningful threshold of 1.0 mL/kg/min, they reported in the Journal of the American Medical Association.

However, the other primary endpoint of quality of life by the Minnesota Living with Heart Failure total score showed nonsignificant improvement over controls of only one point on the 105-point scale with exercise and six points with diet main (P=0.70 and P=0.08).

There's no clear explanation for why exercise capacity -- a major contributor to reduced quality of life in heart failure -- wouldn't translate to a quality of life benefit, , of Emory University in Atlanta, wrote in an accompanying editorial.

"One possibility is that patients with HFPEF test their newly acquired activity tolerance to the precipitation of exertional dyspnea (i.e., they remain symptomatic)," she noted.

Also, there were exploratory quality-of-life (QOL) measures in the study that did register a significant benefit with lifestyle intervention, "the KCCQ score (a heart failure-specific QOL instrument) and the SF-36 physical score (a general QOL instrument)," the researchers noted, which "raised the possibility of an effect on QOL."

But they cautioned 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."

Wenger agreed that there are plenty of clinical questions left to be answered but didn't suggest that should hold clinicians back from implementation.

She wrote that "it seems that clinicians could communicate the transformative message to the older obese population of primarily women with HFPEF that improvement in exercise capacity might be attained by inexpensive and readily available lifestyle measures (such as caloric restriction and aerobic exercise) and by encouragement and guidance to do either or both."

"The disconnect between an improved exercise tolerance and perceived quality of life is disappointing but underscores our incomplete understanding of the pathophysiologic mechanisms that lead to the adverse patient-related symptoms in HFpEF," commented , of the University of Pennsylvania in Philadelphia and a past president of the American Heart Association.

"Nevertheless, it is hard to imagine that a program that promotes weight loss and an enhanced functional capacity can be bad for the patient -- the obesity paradox notwithstanding," she concluded in an email to 乌鸦传媒. "I would recommend this study to my patients."

The study included 100 people ages 60 and older with chronic, stable HFpEF and a body mass index of 30 kg/m² or greater (mean 39.3 kg/m²) who were randomized to a two-by-two factorial intervention at an urban academic medical center.

For 20 weeks, participants got a 400 to 450-kcal deficit diet, three 1-hour supervised exercise sessions per week consisting primarily of walking escalated in intensity as tolerated, both, or neither, controlled for attention with telephone calls every 2 weeks.

Adherence to both interventions was good, at 84% for exercise session attendance and 99% for diet adherence. As expected, body weight decreased with the interventions, by 7% with diet alone (7 kg, 15 lbs), 3% with exercise alone (4 kg, 9 lbs), and 10% with both interventions (11 kg, 24 lbs) compared with 1% among controls (1 kg, 2 lbs).

No study-related serious adverse events occurred in any group.

From the American Heart Association: