Preprocedural white blood cell count and death after percutaneous coronary intervention

Abstract

Background 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. Methods 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 × 10 3/μL; quintile 2, 6.58 × 10 3/μL; quintile 3, 7.70 × 10 3/μL; quintile 4, 9.14 × 10 3/μL; and quintile 5, 13.4 × 10 3/μL). Vital status was assessed through the use of the Social Security Death Index. Results 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. Conclusions 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.