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

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.