Aortic Calcification Is Associated with Decreased Abdominal Aortic Aneurysm Growth

Abdominal aortic aneurysm (AAA) rupture remains a significant cause of morbidity and mortality. Although AAA diameter is associated with continued growth and rupture, many other factors remain undetermined. Abdominal aortic calcification is associated with cardiovascular events, but its association with AAA growth remains unclear. The aim of this study was to investigate the relationship between abdominal aortic calcification and AAA growth via post-hoc analysis of the Non-Invasive Treatment of Abdominal Aortic Aneurysm Clinical Trial (N-TA3CT). Arterial calcification and maximum transverse diameter were measured in non-contrast computed tomography (CT) scans in patients enrolled in the N-TA3CT trial. Patients who received a baseline non-contrast CT scan of the abdomen and pelvis and at least one interval CT scan within the 2-year study duration were included in the analysis. For individual abdominal arteries, the calcium score was calculated at baseline and measured over time. Of the 261 randomized patients in the trial, there were 136 patients who met the inclusion criteria for analysis. With univariate analysis, baseline infrarenal aorta (regression coefficient = −0.06; P = .004; Figure) and total abdominal aortic (regression coefficient = −0.03; P = .003) calcium scores were associated with decreased AAA mean transverse diameter growth. Infrarenal calcium score progression (regression coefficient = −0.21; P = .04) was also associated with decreased AAA growth. In a multivariable regression model using backwards elimination, the baseline infrarenal aorta calcium score remained significantly associated with decreased AAA mean transverse diameter growth (regression coefficient = −0.04; P = .03) (Table). In patients with small aortic aneurysms, increasing baseline abdominal aortic calcium scores were associated with decreased AAA growth rates.TableMultivariable regression model of risk factors associated with abdominal aortic aneurysm maximum transverse diameter growth using backward eliminationVariableRegression coefficient (SE)P valueStroke847 (345).02Atrial fibrillation788 (347).02Current tobacco use716 (245).004Volume14.7 (4.4).001Baseline infrarenal aorta calcium score−0.04 (0.02).03Age−32 (15).03Diabetes−763 (258).004Starting terms included variables with univariate associations of P < .20: age, stroke, coronary artery disease, congestive heart failure, diabetes, atrial fibrillation, tobacco use, hypercholesterolemia, angiotensin blocker receptor use, family history of abdominal aortic aneurysm, diuretics, aspirin, antiplatelet s(including aspirin), baseline diameter, baseline volume, baseline calcium score at the superior mesenteric artery, renal, infrarenal, common iliac, external iliac, and total. Open table in a new tab