Abstract
BACKGROUND: Sex-related differences between men and women with small abdominal aortic aneurysms (AAAs) have implications for patient care and research. Women are less likely to be affected by AAA than men in the United States. This study explored sex-related differences in patient characteristics, aneurysm growth and clinical outcomes in the Non-invasive Treatment of Abdominal Aortic Aneurysm Clinical Trial (N-TA3CT). METHOD: : We conducted a retrospective cohort study performing a secondary analysis of data from N-TA3CT (NCT01756833), a placebo-controlled, RCT assessing doxycycline treatment of AAA. We included 166 N-TA3CT participants with baseline AAA maximum transverse diameter ≤ 4.5 cm and at least one follow-up CT scan. We compared patient characteristics, aneurysm growth rates, adverse events, and clinical outcomes between men and women. RESULTS: Among 166 participants, 35 (21.1%) were women and 131 (78.9%) were men. Women were more likely than men to have a family history of AAA (31.4%% versus 16.0%, P = 0.05). Women were less likely to take statins (68.6% versus 84.7%, P = 0.05) or any antiplatelet agent (48.6% versus 77.9%, P = 0.001). Women had significantly faster annual AAA growth rates than men (0.21 versus 0.16 cm/year, P < 0.001). CONCLUSIONS: Within the size range of 3.5-4.5 cm, AAAs grow faster in women than in men. Women with AAA report a family history of AAA more frequently than men do.