1 Year HIIT and Omega-3 Fatty Acids to Improve Cardiometabolic Risk in Stage-A Heart Failure

Objectives: This study aims to determine whether 1 year of high-intensity interval training (HIIT) and omega-3 fatty acid (n-3 FA) supplementation would improve fitness, cardiovascular structure/function, and body composition in obese middle-aged adults at high-risk of heart failure (HF) (stage A).

Background: It is unclear if intensive lifestyle interventions begun in stage A HF can improve key cardiovascular and metabolic risk factors.

Methods: High-risk obese adults (n = 80; age 40 to 55 years; N-terminal pro-B-type natriuretic peptide >40 pg/mL or high-sensitivity cardiac troponin T >0.6 pg/mL; visceral fat >2 kg) were randomized to 1 year of HIIT exercise or attention control, with n-3 FA (1.6 g/daily omega-3-acid ethyl esters) or placebo supplementation (olive oil 1.6 g daily). Outcome variables were exercise capacity quantified as peak oxygen uptake (V.O₂), left ventricular (LV) mass, LV volume, myocardial triglyceride content (magnetic resonance spectroscopy), arterial stiffness/function (central pulsed-wave velocity; augmentation index), and body composition (dual x-ray absorptiometry scan).

Results: Fifty-six volunteers completed the intervention. There was no detectible effect of HIIT on visceral fat or myocardial triglyceride content despite a reduction in total adiposity (Δ: -2.63 kg, 95% CI: -4.08 to -0.46, P = 0.018). HIIT improved exercise capacity by ∼24% (ΔV.O₂: 4.46 mL/kg per minute, 95% CI: 3.18 to 5.56; P < 0.0001), increased LV mass (Δ: 9.40 g, 95% CI: 4.36 to 14.44; P < 0.001), and volume (Δ: 12.33 mL, 95 % CI: 5.61 to 19.05; P < 0.001) and reduced augmentation index (Δ: -4.81%, 95% CI: -8.63 to -0.98; P = 0.009). There was no independent or interaction effect of n-3 FA on any outcome.

Conclusions: One-year HIIT improved exercise capacity, cardiovascular structure/function, and adiposity in stage A HF with no independent or additive effect of n-3 FA administration. (Improving Metabolic Health in Patients With Diastolic Dysfunction [MTG]; NCT03448185).