The relationship between computed tomography-derived body composition, systemic inflammation, and survival in patients with abdominal aortic aneurysm

Abstract

ObjectivePatient selection and risk stratification for elective repair of abdominal aortic aneurysm (AAA), either by open surgical repair or by endovascular aneurysm repair, remain challenging. Computed tomography (CT)-derived body composition analysis (CT-BC) and systemic inflammation-based scoring systems such as the systemic inflammatory grade (SIG) appear to offer prognostic value in patients with AAA undergoing endovascular aneurysm repair. The relationship between CT-BC, systemic inflammation, and prognosis has been explored in patients with cancer, but data in noncancer populations are lacking. The present study aimed to examine the relationship between CT-BC, SIG, and survival in patients undergoing elective intervention for AAA. MethodsA total of 611 consecutive patients who underwent elective intervention for AAA at three large tertiary referral centers were retrospectively recruited for inclusion into the study. CT-BC was performed and analyzed using the CT-derived sarcopenia score (CT-SS). Subcutaneous and visceral fat indices were also recorded. SIG was calculated from preoperative blood tests. The outcomes of interest were overall and 5-year mortality. ResultsMedian (interquartile range) follow-up was 67.0 (32) months, and there were 194 (32%) deaths during the follow-up period. There were 122 (20%) open surgical repair cases, 558 (91%) patients were male, and the median (interquartile range) age was 73.0 (11.0) years. Age (hazard ratio [HR]: 1.66, 95% confidence interval [CI]: 1.28-2.14, P < .001), elevated CT-SS (HR: 1.58, 95% CI: 1.28-1.94, P < .001), and elevated SIG (HR: 1.29, 95% CI: 1.07-1.55, P < .01) were independently associated with increased hazard of mortality. Mean (95% CI) survival in the CT-SS 0 and SIG 0 subgroup was 92.6 (84.8-100.4) months compared with 44.9 (30.6-59.2) months in the CT-SS 2 and SIG ≥2 subgroup (P < .001). Patients with CT-SS 0 and SIG 0 had 90% (standard error: 4%) 5-year survival compared with 34% (standard error: 9%) in patients with CT-SS 2 and SIG ≥2 (P < .001). ConclusionsCombining measures of radiological sarcopenia and the systemic inflammatory response offers prognostic value in patients undergoing elective intervention for AAA and may contribute to future clinical risk predication strategies.