Aneurysmal wall calcification predicts natural history of small abdominal aortic aneurysms

Background The biomechanical properties of the abdominal aortic aneurysm (AAA) wall may hold predictive potential. This study aims to study the potential role of wall calcification in small AAAs. Methods Initial AAA calcification was determined by ultrasonography to be either more or less than 50% of the initial maximal AAA circumference in 122 men with an initial AAA sized 30–49 mm in maximal diameter. The patients were offered annual control scans and refered for surgery, if the AAA diameter exceeded 50 mm. Surgery for AAA from the date of inclusion to 15 March 2005 was identified in the national vascular registry “Karbase”. Mean follow time was 6.15 years. Results The mean annual growth rate was significantly lower in men with an AAA wall calcification above than below 50% (1.72 mm versus 2.97 mm, P = 0.001). The finding persisted after multivariate linear regression analysis adjusting for age, smoking and aspirin use. A total of 12 men with AAA calcification above 50% were operated compared with 25 men with an AAA calcification below 50% (risk ratio: 0.35 (0.18–0.71), P = 0.003). The difference in risk persisted after adjustment for age, smoking and use of aspirin (risk ratio: 0.36 (0.18–0.74), P = 0.008). Conclusion The calcification content in small AAA predicts the natural history of small AAA.