Abstract
New findings:
What is the central question of this study? We aimed to examine oxidative stress, antioxidant capacity, and macro- and microvascular function in response to 30 days of oral antioxidant (AOx) administration in patients with HFrEF. What is the main finding and its importance? We observed a ∼2-fold improvement in macrovascular function, assessed via brachial artery flow-mediated dilation, and a reduction in oxidative stress following AOx administration in patients with HFrEF. The improvement in macrovascular function was reversed one week after treatment cessation. These findings have identified the potential of oral AOx administration to optimize macrovascular health in this patient group.
Abstract:
Heart failure with reduced ejection fraction (HFrEF) is characterized by macrovascular dysfunction and elevated oxidative stress that may be mitigated by antioxidant (AOx) administration. This prospective study assessed flow-mediated dilation (FMD) and reactive hyperemia (RH) responses in 14 healthy, older controls and 14 patients with HFrEF, followed by 30-day oral AOx administration (1 g Vitamin C, 600 I.U. Vitamin E, and 0.6 g α-lipoic acid) in the patient group. Blood biomarkers of oxidative stress (malondialdehyde, MDA) and AOx capacity (ferric-reducing ability of plasma, FRAP) were also assessed. Patients with HFrEF had a lower %FMD (2.63 ± 1.57%) than controls (5.62 ± 2.60%), and AOx administration improved %FMD in patients with HFrEF (30 days: 4.90 ± 2.38%), effectively restoring macrovascular function to that of controls. In a subset of patients, we observed a progressive improvement in %FMD across the treatment period (2.62 ± 1.62%, 4.23 ± 2.69%, 4.33 ± 2.24%, and 4.97 ± 2.56% at days 0, 10, 20, and 30, n = 12) that was abolished 7 days after treatment cessation (2.99 ± 1.78%, n = 9). No difference in RH was evident between groups or as a consequence of the AOx treatment. FRAP levels increased (6.08 ± 2.80 to 6.70 ± 1.59 mM, day vs. 30) and MDA levels fell (6.81 ± 2.80 to 6.22 ± 2.84 μM, day vs. 30) following treatment. These findings demonstrate the efficacy of chronic AOx administration in attenuating oxidative stress, improving AOx capacity, and restoring macrovascular function in patients with HFrEF. This article is protected by copyright. All rights reserved.
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