Letter by Paraskevas Regarding Article, “Risk Factors for Abdominal Aortic Aneurysms: A 7-Year Prospective Study: The Tromsø Study”
To the Editor:
The study by Forsdahl et al1 prospectively identified risk factors for incident abdominal aortic aneurysm (AAA) over a period of 7 years. Statin use was associated with an almost 4-fold increased risk of AAA development (odds ratio, 3.77; 95% confidence interval, 1.45 to 9.81).1
This finding is contradictory to the results of earlier studies. In a long-term follow-up study comparing AAA growth rates in 130 patients with AAAs not undergoing surgery who were treated with or without statins (75 versus 55 patients, respectively), the mean AAA size decreased from 4.6±0.6 at baseline to 4.5±0.6 cm at 23 months in patients treated with statins (P=not significant), while it increased from 4.5±0.6 at baseline to 5.3±0.6 cm at 24 months in patients not receiving statins (P<0.001).2 In a similar long-term follow-up study (median follow-up, 3.1 years; range, 1.1 to 13.1 years), statin users had a significant 1.16 mm lower annual AAA growth rate compared with nonusers (95% confidence interval, 0.33 to 1.99 mm/year; P=0.006).3
Irrespective of a possible effect on AAA expansion, statin use in patients with AAA is associated with reduced long-term vascular morbidity and mortality,2,4 a reduction of the risk of a vascular event,4 as well as improved perioperative and long-term morbidity and mortality rates should these patients undergo surgery.4,5 Based on the findings of the above studies,2–5 it may be misleading to support that statin use is associated with an almost 4-fold increased risk of AAA development.1
So far the positive2,3 (as well as the negative)1 effects of statins on AAAs have only been demonstrated in observational studies. Randomized controlled trials are required to determine whether statin therapy is a growth inhibitor2,3 or a risk factor1 for AAAs.
Forsdahl SH, Singh K, Solberg S, Jacobsen BK. Risk factors for abdominal aortic aneurysms: a 7-year prospective study: the Tromsø Study. Circulation. 2009; 119: 2202–2208.
Paraskevas KI, Liapis CD, Hamilton G, Mikhailidis DP. Are statins an option in the management of abdominal aortic aneurysms? Vasc Endovascular Surg. 2008; 42: 128–134.