Elevated inflammatory markers are associated with worse outcome after percutaneous coronary artery interventions (PCI). An elevation in the white blood cell (WBC) count is a nonspecific response to inflammation. We hypothesized that an elevated WBC count would be a predictor of death in patients undergoing PCI.

A total of 4450 patients undergoing percutaneous coronary artery intervention were divided into quintiles, based on their preprocedural WBC count (mean WBC count: quintile 1, 5.08 × 10³/μL; quintile 2, 6.58 × 10³/μL; quintile 3, 7.70 × 10³/μL; quintile 4, 9.14 × 10³/μL; and quintile 5, 13.4 × 10³/μL). Vital status was assessed through the use of the Social Security Death Index.

There were a total of 504 deaths over a follow-up period of 48 months. The best survival was seen in quintile 2, with an increase in long-term mortality rates seen with both a higher or a lower WBC count (P < .001). This J-shaped curve was preserved after multivariate adjustment, with the adjusted hazard ratio of mortality relative to quintile 2 being 1.95 (95% CI, 1.40 to 2.73) in quintile 1, 1.66 (95% CI, 1.18 to 2.33) in quintile 3, 2.31 (95% CI, 1.67 to 3.17) in quintile 4, and 2.42 (95% CI, 1.76 to 3.34) in quintile 5.

A low or an elevated preprocedural WBC count in patients undergoing PCI is associated with an increased risk of long-term death. Our result provides further evidence to support the important role of inflammation in coronary artery disease.