Impact of White Blood Cell Count After Percutaneous Coronary Intervention on Long-Term Prognosis in Patients with Unstable Angina Pectoris: A Single-Center Retrospective Observational Cohort Study

Objective: An association between white blood cell count (WBC-C) before percutaneous coronary intervention (PCI) and prognosis has been established in patients undergoing PCI. However, the effect of WBC-C after PCI on the long-term prognosis of patients with unstable angina pectoris (UA) is unclear. Methods: A retrospective cohort study was conducted in 1811 consecutive patients with UA. The changes of WBC and subgroup counts before and in the early postoperative stages after PCI were observed by paired Wilcoxon signed-rank test. The Kaplan-Meier method and COX proportional regression model were used to evaluate the association between the incidence of 5-year endpoint events and post-PCI leukocytosis. Results: Leukocytosis and neutrocytosis within 24 hours after PCI were observed in majority of patients with UA, while lymphocyte count significantly decreased after PCI in those patients. There were no significant differences in 5-year all-cause mortality and major adverse cardiovascular and cerebrovascular events (MACCE) between patients in the post-PCI leukocytosis and the control group. However, the 5-year incidence of major adverse cardiovascular events (MACE) was significantly increased in the post-PCI leukocytosis group (p = 0.017, Log rank test). Leukocytosis after PCI was independently associated with the occurrence of MACE (hazard ratio: 1.36; 95% confidence interval: 1.06-1.75; p = 0.015). Conclusion: Peripheral WBC and neutrophil counts within 24 hours after PCI significantly increased in response to PCI in patients with UA, while lymphocyte count significantly decreased after PCI in those patients. The post-PCI leukocytosis offered predictive value for an increased risk of MACE for up to 5 years in patients with UA.