Carotid atherosclerotic plaque instability is one of the major causes of ischemic strokes. Instable plaques are hemorrhagic and contain large amount of infiltrated monocytes (MC). ¹In recent cross-sectional studies, our team demonstrated that atherosclerotic patients practicing moderate physical activity (PA) have less intraplaque hemorrhage² and pro-inflammatory MC³ than non-active ones. The objective of this study is to determine the effect of an individualized home-based PA intervention on carotid atherosclerotic plaque instability. The PACAPh study is a longitudinal, interventional, monocentric, randomized, controlled study. 80 asymptomatic patients will be recruited with carotid stenosis >50%, without indication of surgery or inflammatory diseases. Patients are randomized 1:1 either in the control or in the PA group. The control group follows usual care. Patients of the PA group receive a connected wristlet for daily steps count and a PA instructor call them twice a month to set new daily steps goal. The final objective is to increase by 30% the daily step count. In both groups, fitness, MC subsets and blood coagulation factors are assessed. Twenty-eight patients were included (16 men, 73±8y/o). To date, 10 patients completed the protocol. PA group increases daily steps by 29% whereas control group decreases by 32%. PA group decreases less its quadriceps strength than control group (–20% vs.–28%). Percentage of classical pro-inflammatory MC are increased after the 6 months in the control group while MC subsets percentages are not modified in the PA group. Clotting time remains stable in the PA group after 6 months intervention while decreasing by 30% in the control group.

Fitness results suggest that the PA intervention increases the active behavior of patients while limiting the strength decreases. PA intervention might also limit the shift anti- to pro-inflammatory phenotype of MC and the reduced time of coagulation initiation observed in the control group.