ABSTRACT
OBJECTIVES: Elevated white blood cell count (WBC) can be predictive of adverse outcomes following vascular interventions, but the association has not established using multi-institutional data. We evaluated the predictive value of preoperative WBC after endovascular aneurysm repair (EVAR) for nonruptured abdominal aortic aneurysms (AAAs) in a nationally representative surgical database. METHODS: Patients with nonruptured AAA undergoing EVAR were identified in the vascular-targeted National Surgical Quality Improvement Program (NSQIP) database. Baseline characteristics were compared between patients with WBC <10 K/µL and WBC ≥10 K/µL. Multivariable logistic regression analyses were performed to assess the odds of outcomes. The primary outcome was 30-day mortality. Multiple secondary outcomes including length of stay (LOS) > 1 week, 30-day readmission, lower extremity (LE) ischemia, ischemic colitis, myocardial infarction, and others were assessed based on WBC and patient sex. RESULTS: A total of 10,955 patients were included, with a mean WBC 7.7 ± 2.7 K/µL. Patients with WBC ≥10 K/µL were younger (71.8 ± 9.5 years vs 74.1 ± 8.7 years; P < .001) and were more likely to be diabetic, on steroids, smokers, functionally dependent, and presenting emergently (all P ≤ .009). Aneurysm diameter was larger in patients with WBC ≥10 K/µL (5.9 ± 1.5 cm vs 5.7 ± 1.5 cm; P < .001). Patients with WBC ≥10 K/µL had more mortality (2.4% vs 1.3%), LOS >1 week (13.5% vs 6.7%), 30-day readmissions (9.8% vs 7.3%), LE ischemia (2.3% vs 1.4%), ischemic colitis (1.2% vs 0.5%), and myocardial infarction (2.0% vs 1.1%) (all P ≤ .008). Female patients with WBC ≥10 K/µL, compared with male patients with WBC ≥10 K/µL, had more adverse events, including mortality, LOS >1 week, 30-day readmission, and LE ischemia (all P ≤ .025). With each incremental increase in WBC by 1 K/µL, the adjusted odds ratio of adverse outcomes for all patient was higher (mortality: 1.05; 95% confidence interval [CI], 1.00-1.10; readmission: 1.03; 95% CI, 1.00-1.06; LOS >1 week: 1.08; 95% CI, 1.05-1.10; and ischemic colitis: 1.11; 95% CI, 1.05-1.16; all P < .05). The effect was more pronounced in female patients and was statistically significant. CONCLUSIONS: WBC is a predictor of adverse outcomes in patients undergoing EVAR for nonruptured AAA. After adjusting for associated risk factors, the effect of increasing WBC was more prominent for female patients. Preoperative WBC should be used as a prognostic factor to predict adverse outcomes among patients undergoing EVAR.
