Influence of a six-month home-based individualized physical activity intervention on carotid plaque instability measured by magnetic resonance imaging: a randomized controlled clinical trial

Background: Management of asymptomatic patients with carotid atherosclerotic plaque is still debated. Intraplaque haemorrhage measured by magnetic resonance imaging is the best in-vivo indicator of plaque instability and ischaemic risk. A cross-sectional study reported that physical activity was associated with lower prevalence of carotid intraplaque haemorrhage. The aim of this trial was to determine the influence of a physical activity intervention on plaque instability in asymptomatic patients with carotid stenosis. Methods: Physical Activity and Carotid Atherosclerotic Plaque haemorrhage is a randomized clinical trial (ID-RCB:2019-A01543-54/SI:19.06.21.40640; registered on clinicaltrials.gov NCT04053166). Patients were enrolled at University Hospital of Lyon, France, from December 2019 to March 2022. Fifty-six asymptomatic patients with carotid artery stenosis ≥50% NASCET were included and randomized 1:1 in an interventional physical activity arm or a control arm. The interventional arm underwent 6 months of an individualized home-based physical activity program, while the control arm followed usual care. The main outcome is the variation of the intraplaque haemorrhage score measured with high-resolution magnetic resonance imaging of the carotid plaque. All data were analysed with an intention to treat. Investigators were blinded from grouping. Findings: Out of 52 patients participating in the trial, 26 were allocated in each arm. The intraplaque haemorrhage score was significantly reduced over time in the physical activity arm (estimate difference: −0.32 ± 0.15, [95% CI −0.63 to −0.01], p = 0.04). The physical activity arm had increased daily step counts at the end of the 6-month intervention compared to the control arm (1843 ± 758, [CI95% 313–3373], p = 0.02). Interpretation: This trial demonstrates that an individualized home-based physical activity intervention could reduce the severity of intraplaque haemorrhage detected by magnetic resonance imaging and that it is feasible in asymptomatic patients with carotid atherosclerotic plaque. These results suggest that this type of moderate-intensity physical activity could be included in this population to the best medical treatment. Funding: This study was funded by the Fédération Française de Cardiologie and Nouvelle Société Francophone d'Athérosclérose.