Blood Flow Restriction Resistance Exercise Improves Muscle Strength and Hemodynamics, but Not Vascular Function in Coronary Artery Disease Patients: A Pilot Randomized Controlled Trial

Abstract

Resistance training may be associated with unfavorable cardiovascular responses (such as hemodynamic alterations, anginal symptoms or ventricular arrhythmias). In healthy adults, blood flow-restricted (BFR) resistance training improves muscle strength and hypertrophy improvements at lower loads with minimal systemic cardiovascular adverse responses. The aim of this study was to assess the safety and efficacy of BFR resistance training in patients with coronary artery disease (CAD) compared to usual care. Patients with stable CAD were randomized to either 8 weeks of supervised biweekly BFR resistance training (30–40% 1RM unilateral knee extension) or usual exercise routine. At baseline and after 8 weeks, patients underwent 1-RM knee extension tests, ultrasonographic appraisal of vastus lateralis (VL) muscle diameter and of systemic (brachial artery) flow-mediated dilation, and determination of markers of inflammation (CD40 ligand and tumor necrosis factor alfa), and fasting glucose and insulin levels for homeostatic model assessment (HOMA). A total of 24 patients [12 per group, mean age 60 ± 2 years, 6 (25%) women] were included. No training-related adverse events were recorded. At baseline groups significantly differ in age (mean difference: 8.7 years, p < 0.001), systolic blood pressure (mean difference: 12.17 mmHg, p = 0.024) and in metabolic control [insulin ( p = 0.014) and HOMA IR ( p = 0.014)]. BFR-resistance training significantly increased muscle strength (1-RM, +8.96 kg, p < 0.001), and decreased systolic blood pressure (-6.77 mmHg; p = 0.030), whereas VL diameter (+0.09 cm, p = 0.096), brachial artery flow-mediated vasodilation (+1.55%; p = 0.079) and insulin sensitivity (HOMA IR change of 1.15, p = 0.079) did not improve significantly. Blood flow restricted resistance training is safe and associated with significant improvements in muscle strength, and may be therefore provided as an additional exercise option to aerobic exercise to improve skeletal muscle functioning in patients with CAD. Clinical Trial Registration: www.ClinicalTrials.gov , identifier: NCT03087292.

Effect of blood‐flow restricted vs heavy‐load strength training on muscle strength: Systematic review and meta‐analysis

“…However, numerous facets of LL‐BFR exercise training have yet to be thoroughly investigated. Clinical studies involving this exercise modality in various patient groups remain somewhat sparse . Parameters such as self‐exercise feasibility and user's perception of the exercise modality, as listed by ACSM to optimize exercise compliance, have yet to be investigated in relation to BFR training protocols.…”

“…Clinical studies involving this exercise modality in various patient groups remain somewhat sparse. 24,[54][55][56][57] Parameters such as T A B L E 2 Percentage changes in muscle cross-sectional area (CSA) or muscle thickness (MT) measured with either circumference measurement, magnetic resonance imaging (MRI), or ultrasonography (US)…”

<p>Strength training with blood flow restriction – a novel therapeutic approach for older adults with sarcopenia? A case report</p>

“…Some recent studies reinforce this premise. Kambic et al19 compared two groups of older patients with coronary artery disease, which performed resistance exercises along with LI-BFR (1 RM of unilateral knee extension with 30–40% occlusion) and continuous aerobic exercise. The strength increased in both groups, while brachial artery flow-mediated vasodilation and insulin resistance remained unchanged.…”

Techniques de renforcement musculaire en réadaptation cardiaque

“…D'une manière générale, on observe une progression modeste des paramètres hémodynamiques (débit cardiaque, fraction d'éjection) alors que les gains de force musculaire segmentaire sont constants et souvent considérables [17]. L'entraînement avec réduction du débit sanguin local est à l'étude en cardiologie [18,19]…”