Abstract
BACKGROUND: Determinants of coronary artery disease, such as endothelial dysfunction and oxidative stress, could be attenuated by high-intensity aerobic interval exercise training (HIIT). However, the volume of this type of training is not well established. OBJECTIVE: To assess the impact of two volumes of HIIT, low (LV-HIIT, <10 min at high intensity) and high (HV-HIIT, >10 min at high intensity), on vascular-endothelial function in individuals after an acute myocardial infarction (AMI). MATERIALS AND METHODS: Clinical trial in 80 AMI patients (58.4 ± 8.3 years, 82.5% men) with three study groups: LV-HIIT (n = 28) and HV-HIIT (n = 28) with two sessions per week for 16 weeks and control group (CG, n = 24) with unsupervised physical activity recommendations. Endothelial function (brachial flow-mediated dilation, FMD), atherosclerosis (carotid intima-media thickness ultrasound, cIMT), and levels of oxidized low-density lipoprotein (ox-LDL) as a marker of oxidative stress were determined before and after the intervention period. RESULTS: After the intervention, in the exercise groups, there was an increase in FMD (LV-HIIT, ↑58.8%; HV-HIIT, ↑94.1%; p < 0.001) concurrently with a decrease in cIMT (LV-HIIT, ↓3.0%; HV-HIIT, ↓3.2%; p = 0.019) and LDLox (LV-HIIT, ↓5.2%; HV-HIIT, ↓8.9%; p < 0.001), with no significant changes in the CG. Furthermore, a significant inverse correlation was observed between ox-LDL and endothelial function related to the volume of HIIT training performed (LV-HIIT: r = -0.376, p = 0.031; HV-HIIT: r = -0.490, p < 0.004), with no significance in the CG (r = 0.021, p = 0.924). CONCLUSION: In post-AMI patients, HIIT may lead to a volume-dependent enhancement in endothelial function, attributed to a decrease in oxidative stress, with added beneficial effects in reducing vascular wall thickness. An LV-HIIT program, with less than 10 min at high intensity per session, has proven enough efficiency to initiate favorable vascular-endothelial adaptations, potentially reducing cardiovascular risk among patients with coronary artery disease. TRIAL REGISTRATION: INTERFARCT, ClinicalTrials.gov: NCT02876952.