Association between baseline white blood cell count and future cardiovascular events in patients with stable coronary artery disease- Sub-analysis of the REAL-CAD trial-

Background: Elevated white blood cell (WBC) counts have been associated with major adverse cardiovascular events (MACE). However, their incremental prognostic values, especially considering factors such as race, sex difference, clinical characteristics, and statin dosage, are not well defined. This study aimed to explore the relationship between baseline WBC counts and subsequent MACE in Japanese patients with stable coronary artery disease (CAD) receiving high and low doses of pitavastatin, as a sub-analysis of the REAL-CAD study. Methods and Results: A total of 10,123 patients with baseline WBC count data were included in this analysis. Patients were categorized into quartiles based on their baseline WBC counts, and the cumulative 4-year incidence of MACE, defined as cardiovascular death, nonfatal myocardial infarction, nonfatal ischemic stroke, or unstable angina requiring hospitalization, was compared among the quartiles. MACE occurred in 491 patients, and Kaplan-Meier curve analysis showed a significantly higher incidence of MACE in the fourth quartile compared with the first quartile (hazard ratio [HR]: 1.910, 95 % confidence interval [CI]: 1.477–2.471). Multivariate analysis indicated that the highest quartile of WBC count was an independent determinant of future MACE (HR: 1.879, 95 %CI: 1.439–2.454), adjusting for age, sex, diabetes, current smoking, statin dosage, and baseline high-sensitive C-reactive protein. Conclusions: Elevated WBC counts increased the risk of cardiovascular events in Japanese patients with stable CAD, highlighting the importance of inflammation as a residual risk after statin treatments in the Japanese population. Further research is needed to evaluate the clinical benefits of screening and treatment strategies based on WBC counts.