Effect of Preoperative White Blood Cell Count on Postoperative Course in Patients with Coronary Artery Bypass Grafting

Son, Kuk Hui; Kim, Jae Ho; Kim, Joung Taek; Yoon, Yong Han; Kim, Kwang Ho; Baek, Wan Ki

Abstract

BACKGROUND: There are several studies that report the relationship between leukocytosis and cardiovascular disease mortality. Most of these studies stand on the basis that atherosclerosis is mediated by inflammatory process. By the same token, preoperative white blood cell count is suggested as an independent predictable factor of postoperative mortality and morbidity in coronary artery bypass grafting. The purpose of this study is to define the influence of preoperative white blood cell count on postoperative morbidity and mortality after coronary artery bypass grafting. MATERIAL AND METHOD: The medical records of the 133 patients who had undergone isolated coronary artery bypass grafting at Inha University Hospital from 1996 to 2003 were reviewed. Patients were evenly divided into four groups, and named as group A, B, C, and D respectively based on their preoperative white blood cell count in ascending order. The number of patients in each group were 33 with exception of 34 in group A. The range of white blood cell count were from 1.3 x 10(3)/microL to 5.9 x 10(3)/microL in group A, from 6.0 x 10(3)/microL to 7.0 x 10(3)/microL in group B, from 7.1 x 10(3)/microL to 8.9 x 10(3)/microL in group C, and from 8.9 x 10(3)/microL to 16.9 x 10(3)/microL in group D. RESULT: The number of patients with recent myocardial infarction was 0 in group A, 2 (6.1%) in group B, 4 (12.1%) in group C, and 8 (24.3%) in D group, showing proportional increase to the white blood cell count (p<0.01). There were six postoperative deaths; 1 (2.9%) in group A, 1 (3.0%) in group B, 2 (2.6%) in group C, and 2 (6.1%) in group D (p=0.44), showing no significant difference between the groups. Postoperative wound infection occurred in 3 patients; all 3 patients were in group D, showing that postoperative wound infection is closely related to the preoperative white blood cell count.
CONCLUSION
The association between preoperative white blood cell count and postoperative mortality could not be defined. The incidence of postoperative wound infection was found to be proportional to the preoperative white blood cell counts.