Athero-occlusive Disease Appears to be Associated with Slower Abdominal Aortic Aneurysm Growth: An Exploratory Analysis of the TEDY Trial

Abstract

The role of atherosclerosis in abdominal aortic aneurysm (AAA) pathogenesis is controversial. The aim of this study was to compare AAA growth in patients who did and did not have concurrent athero-occlusive disease (AOD). Patients with an AAA measuring 35 - 49 mm in maximum diameter were recruited as part of the TElmisartan in the management of abdominal aortic aneurysm (TEDY) trial. TEDY participants who had infrarenal aortic volume and orthogonal diameter assessed by computed tomography at entry and at least one other time point during the trial (12 and/or 24 months) were included. AOD was defined by prior diagnoses of coronary heart disease, stroke, or peripheral arterial disease or an ankle brachial pressure index < 0.90. The increase in AAA volume and diameter from entry for participants who did and did not have AOD was assessed using linear mixed effects models; 131 of the 210 participants recruited to TEDY were included. In an unadjusted analysis, the mean (95% confidence interval) annual increases in AAA volume and diameter for participants with AOD were 3.26 (0.82 - 5.70) cm3 and 0.70 (0.19 - 1.22) mm slower than those without AOD, p= .008 and .007 respectively. The association between AOD and significantly slower AAA growth was maintained after adjusting for risk factors and medications, significantly unequally distributed between participants with and without an AOD diagnosis. In an exploratory analysis of a selective cohort from the TEDY trial, AOD was associated with slower AAA growth. Validation of these findings in other cohorts is needed.