HIIT Shown to Improve Cardiometabolic Risk in Heart Failure

This analysis of data from the Improving Metabolic Health in Patients With Diastolic Dysfunction (MTG) study show the positive effects of high-intensity interval training (HIIT) on stage A heart failure (HF)-related outcomes of fitness level, cardiovascular (CV) structure/function, and body composition, according to the findings published in JACC: Heart Failure.

This study enrolled 80 obese middle-aged patients with stage A heart failure, at risk of developing HF with preserved ejection fraction, at the Institute for Exercise and Environmental Medicine in Dallas, Texas, and evaluated them for improvements in several CV and metabolic risk factors. They were recruited from the Dallas Heart Study and the University of Texas Southwestern Medical Center, as well as through employees at Texas Health Resources and local media, and all underwent 1 year of HIIT and omega-3 fatty acid supplementation (n-3 FA).

All of the recruited participants were considered high risk if they had an N-terminal pro–B-type natriuretic peptide level above 40 pg/mL or high-sensitivity cardiac troponin T above 0.6 pg/mL and visceral fat of more than 2 kg, and each was randomized to 1 year of HIIT or attention control and supplementation with either n-3 FA in the form of daily 1.6-g omega-3-acid ethyl esters or placebo of 1.6 g of olive oil each day. Most were White, currently taking an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker or lipid-lowering agent, and 47 years or older.

“In contrast to older adults and patients with established CV disease, healthy middle-aged adults retain the ability to respond to exercise training by increasing LV distensibility and arterial compliance,” the authors wrote. “Whether obese high-risk middle-aged adults have similar CV plasticity in response to long-duration exercise training is unknown.”

Among the 70% of the initial study cohort who completed their intervention, total adiposity did drop by 2.63 kg (95% CI, –4.08 to –0.46; P = .018). In addition, improvements in exercise capacity, left ventricular (LV) mass and volume, and augmentation index—the latter 2 being indicators of physiologic cardiac remodeling—were seen following the year of HIIT:

• Exercise capacity increased close to 24%, or relative peak oxygen uptake of 4.46 mL/kg/min (95% CI, 3.18-5.56; P < 0.0001)
• Absolute peak oxygen uptake increased 0.43 L/min (95% CI, 0.32-0.53; P < .001)
• LV mass increased 9.40 g (95% CI, 4.36-14.44; P < .001)
• LV volume increased 12.33 mL (95% CI, 5.61-19.05; P < .001)
• Augmentation index was reduced by 4.81% (95% CI, –8.63% to –0.98%; P = .009)

The authors attribute the increase in peak oxygen uptake to upticks in both peak cardiac output and stroke volume, which saw increases of 2.15 L/min (95% CI, 0.90-3.39; P = .001) and 9.46 mL (95% CI, 0.65-18.27; P = .04), respectively.

Neither n-3 FA supplementation alone or in combination with HIIT was shown to have an impact on any hemodynamic parameter during exercise, and neither intervention had positive effects on arterial stiffness.

“These findings indicate that targeting obese high-risk middle-aged adults with HIIT improves fitness and induces physiologic cardiac remodeling,” the authors concluded. “However, complementary interventions focusing on weight loss are likely needed to impact body composition, visceral adiposity, and myocardial triglyceride content.”

Reference

Hearon CM, Dias KA, MacNamara JP, et al. 1 year of HIIT and omega-3 fatty acid supplementation to improve cardiometabolic risk in stage-a heart failure. JACC Heart Fail. Published online March 9, 2022. doi:10.1016/j.jchf.2022.01.004