Statins Fail to Slow Progression of Small AAAs
The prescription of statin therapy does not slow the expansion of abdominal aortic aneurysms (AAA), according to the results of new study.[1] Similarly, there was no association with AAA expansion and LDL- and total-cholesterol levels, report investigators.
The negative results, according to lead author Dr. Craig Ferguson (James Cook University, Queensland, Australia), highlight the "need for ongoing preclinical studies and randomized trials designed to develop medication targeted specifically at reducing AAA growth."
Publishing the findings in the February 2010 issue of the American Heart Journal, the authors point out that most AAAs detected by screening programs measure < 55 mm in diameter, which is too small for surgery. As a result, the aneurysm is treated with further monitoring until it expands above the intervention threshold. Data from some small observational studies have suggested that statin therapy might be a noninvasive way of slowing the progression of the AAA.
In total, 652 patients with a small AAA were included in the study. Of these patients, 349 were prescribed statins, the most common being simvastatin and atorvastatin. Despite treatment, however, AAA growth rates were similar in both treatment arms. Adjusting for baseline characteristics, researchers report that statin prescription was not associated with AAA growth. LDL- and total-cholesterol levels were also not associated with AAA growth rates, despite significantly lower cholesterol levels in the treatment arm.
"Thus, our findings support other evidence suggesting that the mechanisms involved in AAA progression are distinct from those of atherosclerosis," writes Ferguson and colleagues.
Asked by heartwire if AAA patients are ever treated with statins, Dr. Steven Nissen (Cleveland Clinic, Ohio), who was not part of the current study, said they weren't because there is no evidence to support their use.
In the current study, individuals with diabetes were significantly more likely to have an above-the-median expansion of the aneurysm, a finding that has been reported in other trials.
1. Ferguson CD, Clancy P, Bourke B, et al. Association of statin prescription with small abdominal aortic aneurysm. Am Heart J 2010;159:307-311.
