Dissection Risk Up With Larger Thoracic Aortic Aneurysm Size

MONDAY, Oct. 17, 2022 (HealthDay News) -- For patients with thoracic aortic aneurysm (TAA), the absolute risk for aortic dissection (AD) is low but increases with larger aortic sizes, according to a study published online Oct. 5 in JAMA Cardiology.

Matthew D. Solomon, M.D., Ph.D., from Kaiser Permanente Northern California in Oakland, and colleagues examined the association of TAA size with outcomes in nonsyndromic patients. A total of 6,372 TAA patients were identified between 2000 and 2016, with a mean initial TAA size of 4.4 cm.

The researchers found that across a mean follow up of 3.7 years, the rates of AD were low (incidence, 0.22 events per 100 person-years). In multivariable models, larger initial aortic size was associated with a higher risk for AD and all-cause death, with an inflection point in risk at 6.0 cm. In time-updated models, the estimated adjusted risks for AD were 0.3, 0.6, 1.5, 3.6, and 10.5 percent within five years for patients with TAA size of 4.0 to 4.4, 4.5 to 4.9, 5.0 to 5.4, 5.5 to 5.9, and 6.0 cm or larger, respectively. Rates of the composite of AD and all-cause death were higher than for AD alone; at 6.0 cm, a similar inflection point was observed for increased risk.

"Larger aortic size was associated with higher risk of AD and all-cause death after adjustment for potential confounders and competing risks, but absolute risk of AD was low in the overall cohort with an inflection point at 6.0 cm, supporting current guidelines recommending surgery at 5.5 cm," the authors write.

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