Randomized Placebo-Controlled Trial Assessing the Effect of 24-Week Fenofibrate Therapy on Circulating Markers of Abdominal Aortic Aneurysm: Outcomes From the FAME -2 Trial.

Background There is no drug therapy for abdominal aortic aneurysm ( AAA ). FAME-2 (Fenofibrate in the Management of Abdominal Aortic Aneurysm 2) was a placebo-controlled randomized trial designed to assess whether administration of 145 mg of fenofibrate/d for 24 weeks favorably modified circulating markers of AAA. Methods and Results Patients with AAA s measuring 35 to 49 mm and no contraindication were randomized to fenofibrate or identical placebo. The primary outcome measures were the differences in serum osteopontin and kallistatin concentrations between groups. Secondary analyses compared changes in the circulating concentration of AAA -associated proteins, and AAA growth, between groups using multivariable linear mixed-effects modeling. A total of 140 patients were randomized to receive fenofibrate (n=70) or placebo (n=70). By the end of the study 3 (2.1%) patients were lost to follow-up and 18 (12.9%) patients had ceased trial medication. A total of 85% of randomized patients took ≥80% of allocated tablets and were deemed to have complied with the medication regimen. Patients' allocated fenofibrate had expected reductions in serum triglycerides and estimated glomerular filtration rate, and increases in serum homocysteine. No differences in serum osteopontin, kallistatin, or AAA growth were observed between groups. Conclusions Administering 145 mg/d of fenofibrate for 24 weeks did not significantly reduce serum concentrations of osteopontin and kallistatin concentrations, or rates of AAA growth in this trial. The findings do not support the likely benefit of fenofibrate as a treatment for patients with small AAA s. Clinical Trial Registration URL : www.anzctr.org.au . Unique identifier: ACTRN 12613001039774.

Infra-renal abdominal aortic calcification volume does not predict small abdominal aortic aneurysm growth.

BACKGROUND: Vascular calcification is a common finding in abdominal aortic aneurysms (AAA) however whether it predicts aneurysm expansion is controversial. OBJECTIVES: 1) To establish a reproducible method of assessing AAA calcification using computed tomography (CT); 2) To investigate the association between AAA calcification and growth. METHOD: Patients were identified from a prospectively maintained small AAA surveillance database. To be included patients required at least two CT scans a minimum of 6 months apart. All patients had a maximal AAA diameter of ≤55 mm on their initial scan. Infra-renal aortic calcification volume, total infra-renal aortic volume and maximal AAA diameter were measured. Reproducibility was assessed from repeat scans performed on 31 patients. AAA growth, estimated by volume change per year, was compared between patients with baseline infra-renal aortic calcification volumes< and ≥median. RESULTS: 95% agreement limits (lower, upper) for intra and inter-observer error in measuring infra-renal aortic calcification volume were 0.68, 97 mm(3) and -140, 5.8 mm(3), respectively. Concordance correlation coefficients for inter and intra-observer variability in measuring infra-renal aortic calcification volume were 0.99 and 0.99, respectively. Patients with infra-renal aortic calcification volume < median (n = 44) and ≥median (n = 44) had an infra-renal aortic volume increase of 6.0 cm(3)/yr and 7.8 cm(3)/yr, respectively (p = 0.66). Mean percentage infra-renal aortic volume increase/yr was found to be 4.2 ± 6.4 and 8.9 ± 6.2 for patients with and without diabetes, respectively (p = 0.003). CONCLUSION: Infra-renal aortic calcification volume can be assessed reproducibly from CT images. Infra-renal aortic calcification volume did not predict small AAA growth.

Growth rates of small abdominal aortic aneurysms assessed by computerised tomography--a systematic literature review.

BACKGROUND: Most current evidence examining abdominal aortic aneurysm (AAA) growth is based on ultrasound surveillance. OBJECTIVE: This review aimed to systematically analyse studies which have assessed small AAA growth using computed tomography (CT) to monitor outcome. METHOD: Studies investigating small AAA expansion rates using CT images were identified by searching the PubMed database and hand searching article reference lists. Eligible studies must have focused on monitoring small AAA growth using CT and included patients with baseline AAA diameters <55 mm for which growth rates were reported. RESULTS: Ten studies including 845 patients met eligibility with average baseline AAA diameters ranging from 36.2 to 50.5 mm. AAA growth was assessed using axial (n = 1), orthogonal (n = 2), anterior to posterior (n = 4), and unspecified (n = 3) measurement methods. One study reported the reproducibility of their assessment method. Mean AAA diameter growth rates ranged from 2.6 to 5.2 mm/year. Factors reported to be associated with increased AAA expansion included: large AAA thrombus size (n = 3 studies), large baseline AAA diameter (n = 2), high AAA wall stress, elevated plasma concentration of matrix metalloproteinase-9 and presence of carotid artery disease (n = 1 study each). Factors reported to be negatively associated with AAA growth included presence of diabetes mellitus and chronic limb ischaemia (n = 1 study each). CONCLUSION: Many currently reported studies assessing small AAA growth on CT fail to report consistent use of reproducible measurement methods. CT offers the opportunity to assess orthogonal diameter and perform central reading which could be an advantage of this form of imaging.