Leukocytosis and clinical outcomes in acute inferior myocardial infarction

An elevated white blood cell count (WBC) on hospital admission has been shown by numerous studies to be associated with increased mortality and morbidity in patients with acute coronary syndromes [1–4]. For patients with anterior wall acute myocardial infarction (AMI), neutrophil counts on admission were associated with infarct size and left ventricular systolic function in the chronic phase [5]. However, the association between initial WBC count and clinical outcomes specifically for acute inferior MI remains unclear. We retrospectively reviewed the clinical characteristics and in-hospital outcomes of 406 patients (295 men, 111 women, mean age 64.8±12.9 years) with the diagnosis of acute inferior MI at our institution from January 1997 to March 2004. Patients were stratified into three subgroups based on initial WBC recorded at the time of hospital admission .The baseline WBC count ranged from 3.1 to 32.4×10 cells/mm. The mean WBC count was 11.37± 3.9×10 cells/mm and the 25th and 75th percentiles were, 8.67×10 cells/mm and 13.12×10 cells/mm respectively. The three subgroups consisted of low WBC subgroup: WBC ≤8.67×10 cells/mm, intermediate WBC subgroup: WBC 8.68–13.12×10 cells/mm and high WBC subgroup: WBC N13.12×10 cells/mm. Baseline clinical characteristics are shown in Table 1. Patients in the uppermost WBC subgroup were more often men, had a history of smoking and had a higher hemoglobin level.