Ascending thoracic aneurysms are associated with decreased systemic atherosclerosis

Study objectives: We noted clinically that patients with aortic root aneurysms and dissections seemed to have little systemic atherosclerosis. It is our objective to determine whether there is a negative association between ascending thoracic aneurysms and systemic atherosclerosis. Design: Atherosclerosis was quantified by evaluating noncontrast CT images of the chest and scoring the degree of calcifications as a marker for atherosclerosis in the coronary arteries and aorta. Patients: The degree of calcification was compared in 64 patients with aortic root aneurysm (annuloaortic ectasia, 31 patients; type A dissection, 33 patients) vs 86 control subjects. Multivariable analysis was applied to test for an association between aortic root aneurysms and systemic calcification independent of risk factors for atherosclerosis. Results: Multivariable analysis revealed that patients with ascending aortic aneurysms of the annuloaortic ectasia type and patients with type A dissections had significantly lower overall calcification scores in their arterial vessels compared to patients in the control group (p = 0.03 and p < 0.0001, respectively). These results were independent of all other risk factors for atherosclerosis. Smoking, dyslipidemia, diabetes, and age were all found to increase the degree of atherosclerosis (p < 0.01 to 0.05). Conclusions: Aortic root pathology (annuloaortic ectasia or type A dissection) is associated with decreased systemic atherosclerosis. It is possible that a mechanism exists whereby the same genetic mutations predisposing patients to ascending aortic aneurysms also exert a protective effect against systemic atherosclerosis.