Exercise Intervention May Slow HF Progression Before Disease Takes Hold

— HIIT improved fitness, induced favorable cardiac remodeling in people with stage A heart failure

MedpageToday
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Regular high-intensity interval training (HIIT) improved some markers of cardiovascular health in people at risk of developing heart failure (HF), researchers found.

In a small randomized trial, 1 year of HIIT reduced total adiposity but had no effect on visceral fat or myocardial triglyceride content in 56 adults with obesity and elevated cardiac biomarkers, reported Satyam Sarma, MD, of Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, and colleagues.

However, the HIIT intervention improved fitness and induced favorable cardiac remodeling in these patients with stage A HF:

  • Peak VO2 improved by 4.46 mL/kg per minute (95% CI 3.18-5.56)
  • Left ventricular (LV) mass increased by 9.40 g (95% CI 4.36-14.44)
  • LV volume increased by 12.33 mL (95% CI 5.61-19.05)
  • Augmentation index reduced by 4.81% (95% CI -8.63 to -0.98)

"Importantly, exercise training in the absence of weight loss is still associated with improvement in cardiovascular risk in overweight adults. However, future investigations are needed to identify complementary lifestyle interventions that target visceral adipose tissue reduction," the authors wrote in JACC: Heart Failure.

Matthew Nayor, MD, MPH, a cardiologist at Boston University School of Medicine, called the observed improvement in cardiorespiratory fitness in these patients "really impressive."

"I am surprised by the magnitude of improvement in peak fitness levels that was observed despite minor changes to weight or body composition. This finding suggests that HIIT has durable effects on the cardiovascular system's ability to perform exercise, which is a crucial metric of overall health," he said.

Stage A HF indicates a stage of high risk before the patient goes on to develop structural heart disease or symptoms of HF. The subset of stage A patients with high visceral adiposity and elevated cardiac biomarkers is thought to be particularly amenable to lifestyle interventions, Sarma's team noted.

"This study adds to the growing body of literature demonstrating the cardiovascular benefits of exercise training and highlights potential benefits specifically with HIIT," commented Robert Mentz, MD, HF section chief at Duke University Medical Center in Durham, North Carolina.

"Exercise is currently recommended by the global cardiovascular societies and represents an important lifestyle intervention in both patients at risk for HF, as well as those living with HF. I encourage my patients to incorporate exercise training into their lifestyle in order to focus on heart function, not failure, and promote heart success," he said.

HIIT and omega-3 fatty acids have been hypothesized to help prevent HF by targeting mechanisms such as myocardial triglyceride accumulation, inflammation, and lipid metabolism. Yet there was no independent or interaction effect of omega-3 fatty acids on any outcome in the trial.

The study was conducted at Sarma's center, and assigned patients to 1 year of HIIT exercise training (3 to 4 sessions per week at moderate-to-high intensity) or attention control (any combination of yoga, balance, or strength training). Patients were also randomized to omega-3 fatty acid (1.6 g daily omega-3-acid ethyl esters) or placebo (olive oil 1.6 g daily) supplementation atop their exercise assignment.

Sarma and colleagues recruited 80 high-risk patients, of whom 56 (mean age about 50, 57% women) completed their assigned intervention.

Neither HIIT nor omega-3 fatty acid supplementation helped with arterial stiffness. This suggests that "the age-associated and accelerated vascular stiffness in middle-aged stage A HF is difficult to reverse once established," the authors wrote.

The 30% dropout rate was a major caveat of the trial, as was the limited sample of just 39 patients with pre- and post-MRI spectroscopy measures for the myocardial triglyceride analysis, Sarma and team acknowledged.

"While it is certainly well-recognized that exercise is an important component of healthy aging, the optimal type of exercise training is currently unknown. This study clearly establishes that long-term HIIT training has favorable effects on fitness and heart structure and provides insight on mechanisms through which this may occur," Nayor maintained.

"While further study is certainly necessary to establish the optimal exercise training program for overall health, this study does strongly suggest that HIIT training has important, and impressive, health benefits and would likely be a good option for people desiring to improve their cardiovascular health," he added.

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    Nicole Lou is a reporter for MedPage Today, where she covers cardiology news and other developments in medicine. Follow

Disclosures

The study was supported by an American Heart Association grant.

Sarma's group had no disclosures.

Primary Source

JACC: Heart Failure

Source Reference: Hearon CM, et al "1 year of HIIT and omega-3 fatty acid supplementation to improve cardiometabolic risk in stage-A heart failure" JACC Heart Fail 2022; DOI: 10.1016/j.jchf.2022.01.004.