Association of statin prescription with small abdominal aortic aneurysm progression

Background:\ud Statins have been suggested to reduce expansion of abdominal aortic aneurysms (AAAs) independent of lipid-lowering effects.\ud \ud Methods:\ud We assessed the association of statin treatment and serum low-density lipoprotein (LDL) concentrations with small AAA expansion. Six hundred fifty-two patients undergoing surveillance of small AAAs were entered into the study from 5 vascular centers. In a subset, fasting lipids (n = 451) and other biomarkers (n = 216) were measured. The AAA diameter was followed by ultrasound surveillance for a median of 5 years.\ud \ud Results:\ud Three hundred forty-nine (54%) of the patients were prescribed statins. Adjusting for other risk factors, statin prescription was not associated with AAA growth (odds ratio [OR] 1.23, 95% CI 0.86-1.76). Above-median AAA growth was positively associated with initial diameter (OR 1.78 per 4.35-mm–larger initial aortic diameter, 95% CI 1.49-2.14) and negatively associated with diabetes (OR 0.37, 95% CI 0.22-0.62). Above-median serum LDL concentration was not associated with AAA growth. Patients receiving statins had lower serum C-reactive protein concentrations but similar matrix metalloproteinase–9 and interleukin-6 concentrations to those not prescribed these medications.\ud \ud Conclusions:\ud We found no association between statin prescription or LDL concentration with AAA expansion. The results do not support the findings of smaller studies and suggest that statins may have no benefit in reducing AAA progression

Abdominal aortic aneurysm pathology and progress towards a medical therapy

Abdominal aortic aneurysm (AAA) is an important cause of mortality in older adults due to aortic rupture. Surgical repair (either by endovascular or open surgery) is the only treatment for AAA. However, large randomized controlled trials have demonstrated that elective repair of small (<55 mm) AAAs does not reduce all-cause mortality. Most AAAs detected through screening programs or incidental imaging are too small to warrant immediate surgical repair. Such patients are managed conservatively with repeated imaging to monitor AAA diameter. Nonetheless, 60–70% of AAAs managed in this way eventually grow to a size warranting elective surgery. Discovery of a drug therapy which effectively slows the growth of small AAAs has significant potential to improve patient welfare and reduce the number of individuals requiring elective surgery. This chapter reviews the current understanding of AAA pathogenesis gained through assessment of animal models and clinical samples. Previous AAA drug trials are also discussed. Finally, the challenges in developing AAA drugs are outlined