Psychological stress and the progression of carotid artery disease

BACKGROUND: We examined the relation between cardiovascular reactivity (the response of the cardiovascular system to psychological stress) and the severity and progression of carotid atherosclerosis. METHODS: Using duplex ultrasonography, we measured the change in the area of all detectable plaques in the extracranial carotid arteries during 2 years. Cardiovascular reactivity was assessed by measuring changes in hemodynamics during a frustrating cognitive task (the Stroop Color Word Interference Task). Established risk factors for atherosclerosis were measured by interviewing patients, a physical examination, and blood assays for 351 subjects with a wide range of types of atherosclerotic disease. RESULTS: Atherosclerotic plaques were present in the carotid arteries of 273 (78%) subjects. In a forward stepwise multiple regression analysis, it was found that greater age (beta = 0.46), a history of hypertension (beta = 0.20), use of lipid level-lowering agents (beta = 0.18), a longer history of smoking (beta = 0.13), a larger cholesterol:high-density lipoprotein ratio (beta = 0.13), a smaller change in heart rate during the task (beta = -0.12), and a higher resting systolic blood pressure (SBP; beta = 0.11) were associated significantly with a greater plaque area (R2 = 0.35). In 136 untreated subjects who were followed up for 2 years, a greater change in SBP during the task (beta = 0.28), a higher total cholesterol: high-density lipoprotein ratio (beta = 0.23), a shorter resting preejection period (beta = -0.19), and a lower body mass index (beta = -0.17) were significant predictors of the change in atherosclerosis, after controlling for age and initial plaque area in a stepwise multiple regression analysis (R2 = 0.24). CONCLUSIONS: These results support the hypothesis that hemodynamic responses under conditions of mental stress may influence the progression of atherosclerosis.