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 non-contrast 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.