Risk Factor Analyses of Abdominal Aortic Aneurysms Growth in Japanese Patients

Background: This study aimed to retrospectively demonstrate the growth rate (mm/year) of abdominal aortic aneurysm (AAA) diameters (ADs) and to analyze risk factors for AAA expansion.

Methods: We retrospectively investigated the clinical data of 319 patients with AAAs who were followed up as outpatients for >2 years after their initial visit and who underwent computed tomography >4 times.

Results: The mean follow-up period was 3.7 ± 1.5 years. The annual average growth rates according to varying ADs were as follows: 1.9 ± 0.8 (AD 30-34 mm), 2.6 ± 1.2 (AD 35-39 mm), 2.8 ± 1.1 (AD 40-44 mm), 3.1 ± 1.3 (AD 45-49 mm), 3.4 ± 1.6 (AD 50-54 mm), and 3.5 ± 1.4 mm (AD ≥55 mm). Factors associated with AAA expansion were smoking (P = 0.017), hypertension (P < 0.001), and ADs (P < 0.001). In the subgroup analysis, data regarding growth rates of ≥3 mm were extracted, and a statistically significant difference between smoking status and ADs of ≥40 mm was observed.

Conclusions: Factors associated with AAA expansion in Japanese patients included smoking, hypertension, and ADs, and a statistically significant difference was observed between smoking status and ADs of ≥40 mm.