BACKGROUND: Neutrophil-to-lymphocyte ratio (NLR) is a readily available parameter, associated with long-term outcomes in cardiovascular conditions. This study aims to analyze the predictors of NLR and its impact on prognosis and disease-specific outcomes following endovascular aneurysm repair (EVAR). METHODS: Single-center retrospective cohort study. Consecutive patients who underwent elective EVAR (2011-2023) were considered. Primary outcome is short-term major adverse events (MAE) and long-term mortality. Secondary outcomes were freedom-from EVAR failure, aortic reintervention, and NLR predictors. Multivariable logistic regression analyses were performed for binary outcomes. Survival outcomes were analyzed through Kaplan-Meier and Cox regression analyses. RESULTS: Overall, 434 patients were included. A 2.4 NLR cutoff was a fair discriminator for long-term-mortality (area under the curve, 0.62), and groups were dichotomized according to this premise. Increasing age (adjusted odds ratio [aOR]: 1.06
1.03-1.09, per 1-year increase) and a pulmonary comorbidity (aOR: 1.91
1.24-2.96) associated to NLR ≥ 2.4. No significant association between comorbidity burden and NLR was observed. MAE occurred more often if NLR ≥ 2.4 (6.2 vs. 11.6% high-NLR, P = 0.049
NLR ≥ 2.4 aOR: 2.10
1.01-4.36). At 8-years follow-up, survival estimates favored NLR <
2.4 (55.7% vs. 33.7% high-NLR, P <
0.001, NLR ≥ 2.4 adjusted hazard ratio [aHR]: 1.07
1.05-1.98), without differences in freedom-from EVAR failure (70.6 vs. 68.2% high-NLR, P = 0.27, NLR ≥ 2.4 aHR: 1.26
0.82-1.94). Conversely, NLR ≥ 2.4 associated with lower freedom from aortic reinterventions (80.0% vs. 70.2% high-NLR, P = 0.01, NLR ≥ 2.4 aHR: 1.80
1.08-3.01). CONCLUSION: NLR appears as a prognostic marker with reduced impact of comorbidity burden. Following EVAR, it independently predicts MAE and mortality. Over time, elevated NLR appears associated with increased aortic reinterventions, although rates and mode of failure seem similar across groups.