Clinical results of the Physical Activity and Carotid Atherosclerotic Plaque hemorrhage (PACAPh) study

Abstract

Intraplaque hemorrhage (IPH) and intercurrent inflammatory processes cause carotid plaque instability. IPH is the instability factor that better predicts plaque rupture. In two previous cross-sectional prospective study, our team demonstrated that patients practicing moderate physical activity (PA) had lower rates of IPH and pro-inflammatory monocytes. We hypothesized that an individualized home-based PA intervention can reduce IPH and modulate inflammation, as well as monocyte phenotype in asymptomatic patients with a non-endarterectomized carotid atherosclerotic plaque. Fifty-seven patients had been included at Louis Pradel hospital in Lyon. Patients should have been asymptomatic of ischemic events for more than 6 months and present a carotid stenosis > 50%. At inclusion and after 6 months, IPH was measured with a high-resolution MRI, a blood sample was used to quantify the inflammation state and determine the circulation monocytes phenotype, moreover, PA was quantified with a 6 minutes walking test, a test of isometric contraction of the quadriceps and finally, sedentary behavior and PA levels were assessed by questionnaire. Patients were randomly allocated to the control or to the PA intervention group. In the PA group, patients should reach daily goals of steps, measured by a connected watch. Dailly steps goal was reevaluated twice a month, in order to encourage patients to increase their walking habits. Patients in the control group receive their usual care during the protocol. Fifty-two patients finished the study, 26 where randomized in each group. At inclusion, blood test, frequency of comorbidities, associated treatments and risk factors were equivalents between groups. The intervention in PA did improve the physical activity capacity. Indeed, the distance walked during the 6 minutes’ walk test was significantly improved in the PA group. On the clinical side, the PA intervention did allow a 43% reduction in the IPH rates, measured by MRI. IPH is a well-known risk factor of plaque rupture. Thus, MRI is a reliable tool to follow the evolution of IPH and is sensible enough to measure IHP variations du to PA. Moreover, the PA intervention did stabilize the rates of classical pro-inflammatory monocytes, while it increased in the control group, according to the evolution of atherosclerosis.