High levels of endothelin (ET)-1 and aneurysm diameter independently predict growth of stable abdominal aortic aneurysms.

The etiology of abdominal aortic aneurysm (AAA) includes inflammation and endothelial dysfunction. To evaluate relations between these mechanisms and AAA growth, endothelin (ET)-1, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and CD40 ligand were related to yearly AAA growth for 2.9 +/- 1.6 years (mean +/- SD) in 178 patients with conservatively followed AAA. Total number of follow-up years was 491. Abdominal aortic aneurysm diameter increased by 3.3 +/- 4.0 mm during the first year and by 4.9 +/- 4.4 mm during the first 2 years. Median (range) growth was 2.5 (-1.0 to 30.6) mm/year. When patients with AAA growth above or below median were compared, initial AAA diameter (46.1 +/- 5.8 vs 42.0 +/- 8.3 mm; P < .0001), age (75 +/- 7 vs 72 +/- 8 years; P < .029), and initial ET-1 levels (1.31 +/- 0.50 vs 1.13 +/- 0.49 pg/mL; P < .0177) were higher in patients with growth above median. Endothelin 1 (P = .0230) and initial AAA diameter (P = .0019) predicted AAA growth above median in logistic regression. In conclusion, higher initial levels of ET-1 and initial AAA diameter independently predict AAA growth.