Chronic obstructive pulmonary disease (COPD) is a documented risk factor for abdominal aortic aneurysm (AAA) growth and rupture. However, little is known about the impact of COPD on AAA sac behavior after endovascular AAA repair (EVAR). Our objective was to determine the longitudinal association between COPD and sac remodeling after EVAR. All EVAR patients from 2010 to 2021 were identified within the Society of Vascular Surgery-Vascular Quality Initiative. Patients who expired within the first postoperative year or lacked follow-up data were excluded. The primary exposure was COPD severity (none, medically treated, and oxygen-dependent). The primary end point was sac growth after index EVAR. Secondary end points included mortality and reintervention. We used mixed-effects linear and logistic regression to assess the effects of COPD severity on sac remodeling with particular attention to control for the presence of endoleak. Cox-proportional hazards regression identified the predictors of mortality and reintervention. A total of 30,686 EVAR patients met inclusion criteria. The cohort had a mean age of 73 years with 18% female (n = 5519). A total of 24% had documented COPD (none 76% [n = 23,260], medically treated, 20% [n = 6057], oxygen-dependent 4% [n = 1369]), whereas 29% (n = 8803) were active smokers. Persistent sac growth was significantly associated with oxygen-dependent COPD (regression coefficient: +0.55, 95% confidence interval [CI]: 0.046-1.05; P = .03) after EVAR implantation; however, medically treated COPD was not (regression coefficient: −0.06, 95% CI: −0.322 to 0.199; P = .6). Notably, in adjusted analysis, patients with oxygen-dependent COPD did not experience increased reintervention rates (hazard ratio [HR]: 0.88, 95% CI: 0.8-1.02; P = .09), as they were vulnerable to significantly increased mortality (HR: 1.9, 95% CI: 1.74-2.12; P = .01) (Fig). Moreover, mortality was similar among patients irrespective of post-EVAR sac enlargement (HR: 1.2, 95% CI: 0.96-1.4; P = .13). As expected, the incidence of type 2 endoleak was greater among patients with documented sac growth of >5 mm irrespective of COPD severity (26% vs 10%, P < .0001), which also correlated with increased reintervention rates over time (22% vs 4%, P < .0001). Oxygen-dependent COPD was significantly associated with increased sac growth after EVAR. However, patients with oxygen-dependent COPD did not experience increased reinterventions, though this likely reflects the >2-fold risk of mortality within 2 years of their index EVAR. These findings underscore the importance of critical patient selection among those with severe COPD when considering EVAR and justify reserving repair for patients at greatest risk for AAA-related mortality.Fig 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig 3View Large Image Figure ViewerDownload Hi-res image Download (PPT)