Distribution, Determinants and Normal Reference Values of Aortic Arch Width: Thoracic Aortic Geometry in the Framingham Heart Study.

STUDY OBJECTIVE

Aortic arch geometry changes with age, including an increase in aortic arch width (AAW). High AAW is a predictor of incident adverse cardiovascular disease (CVD) events, but its distribution and determinants are unknown. We hypothesized that traditional CVD risk factors, in addition to age, are associated with increased AAW in community-dwelling adults.

STUDY DESIGN

Framingham Offspring and Third Generation cohort participants (N=3026, 52% Men) underwent thoracic multidetector computed tomography (MDCT). A referent group (733M, 738W) free of clinical CVD, hypertension, dyslipidemia, smoking, and diabetes was used to generate sex and 10-year age-group specific upper 90th percentile (P90) cut-points for AAW. AAW was measured as the distance between the cross-sectional centroids of the ascending and descending thoracic aorta. Multivariable logistic regression models were used to identify clinical correlates of high AAW (≥referent P90) in the overall study group.

RESULTS

Among referent participants, AAW increased with greater age-group, p for trend <0.0001 in each sex. Overall and within each age group, AAW was greater in men than women, p<0.0001 all comparisons. Across all participants, high AAW was associated with greater age (odds ratio, OR=1.34/10y; 95% confidence interval 1.20 - 1.50), body surface area (OR=1.97/SD; 1.62 - 2.40), diastolic blood pressure (OR=1.59/10mmHg; 1.40 - 1.81), pack-years smoked (OR=1.07; 1.02 - 1.13), and prevalent CVD (OR=1.64; 1.08 - 2.49).

CONCLUSION

AAW increases with greater age, body size, diastolic blood pressure and burden of smoking. High AAW (≥referent P90) is also associated with prevalent (clinically apparent) CVD. AAW is often seen on and easily measured from tomographic thoracic images and has prognostic value.