Relationship between normal preoperative white blood cell count and major adverse events after endovascular repair for abdominal aortic aneurysm: results of a pilot study

Abstract Study objective To examine the association between preoperative white blood cell (WBC) count within the reference range and major adverse events (MAEs) following endovascular repair of abdominal aortic aneurysms (AAA). Design Prospective observational study. Setting Vascular surgery clinic in a tertiary university hospital. Patients One hundred fifty-three consecutive patients. Intervention Endovascular repair of AAA. Measurements All patients had normal preoperative WBC count (3.5-10.3 K/μL). Postoperative MAE was defined as death, stroke, and myocardial infarction. The prognostic value of preoperative WBC was determined by receiver operating characteristic curves, whereas χ 2 test and Cochran-Armitage trend test were used to assess the association between MAE and different values of WBC. Main results A preoperative WBC cutoff value of 7.3 Κ/μL could predict MAE with 62% sensitivity and 62% specificity (area under the curve, 0.62). Patients with higher preoperative WBC experienced more events compared with patients with lower values ( P =.027). A linear relationship was observed between an increasing preoperative WBC count within the reference range and the risk of postoperative events ( P =.004). Logistic regression analysis showed that preoperative normal WBC count was an independent predictor of MAE and revealed that for every 1-K/μL increase, patients had a 32.8% increase in their relative odds of developing postoperative MAE ( P =.035). Conclusions This pilot study demonstrates a linear correlation between an increasing preoperative WBC count within the reference range and an increased risk for postoperative MAEs following endovascular repair for AAA. Identification of high-risk patients at an early stage by using WBC count could prove useful in implementing measures to improve their clinical outcome.