Predictive value of elevated white blood cell count in patients with preexisting coronary heart disease: the Bezafibrate Infarction Prevention Study

Abstract

Background: Inflammation is implicated in the pathogenesis of atherosclerosis and acute coronary syndromes. White blood cell (WBC) count increases during infections and inflammatory illnesses and has been shown to predict coronary heart disease (CHD) independent of traditional cardiovascular risk factors. This apparent association may reflect a relationship between the WBC count and other coronary risk factors. Studies in patients with CHD are scarce and give conflicting results. The aim of the present study was to investigate the association between WBC count and subsequent coronary events and total mortality in a large cohort of patients with CHD.

Methods: We evaluated the relationship between WBC count and 6-year risk of coronary events and mortality in a large cohort of patients with chronic CHD who were enrolled in a secondary prevention study of bezafibrate.

Results: In univariate analysis, WBC count was associated with an elevated 6-year risk of myocardial infarction, cardiac death, and total mortality. On multivariate adjustment, the positive association with risk of myocardial infarction and cardiac death was eliminated, but WBC count remained predictive of total mortality: relative risk, 1.47; 95% confidence interval, 1.13 to 1.92, in the upper tertile of WBC count (as compared with the lowest). For every 1000/ microL increase in WBC count, risk of total death increased by 6% (relative risk, 1.06; 95% confidence interval, 1.03-1.10).

Conclusions: Elevated WBC count in patients with CHD was associated with higher long-term risk of all-cause mortality. This excess risk of mortality was not due to cardiac causes.