Circulating white blood cell count correlates with left ventricular indices independently of the extent of risk area for myocardial infarction after successful reperfusion

Objective - To test the hypothesis that the circulating white blood cell (WBC) and neutrophil counts are related to left ventricular (LV) indices in patients with the same risk area for acute myocardial infarction (AMI), we examined 100 consecutive AMI patients who had the culprit lesion at segment 6 according to the American Heart Association classification and who underwent successful direct coronary angioplasty. Methods and results - The LV ejection fraction (LVEF), end-systolic volume (LVESVI) and end-diastolic volume index (LVEDVI) were obtained by left ventriculography performed 4 weeks after AMI onset. Univariate analysis disclosed that the counts of WBC and neutrophils on admission, and the maximal WBC count correlated negatively with LVEF (r = -0.46, p < 0.001; r = -0.54, p < 0.001 and r = -0.40, p < 0.001, respectively) and positively with LVESVI (r = 0.43, p < 0.001; r = 0.55, p < 0.001, and r = 0.30, p < 0.01, respectively). The counts of WBC and neutrophils on admission also correlated with LVEDVI (r = 0.28, p < 0.01 and r = 0.41, p < 0.001, respectively). Multivariate analysis with other clinical and angiographic factors revealed that the counts of WBC and neutrophils on admission correlated with LVEF (partial correlation coefficient, r = -0.37, p < 0.001 and r = -0.52, p < 0.001, respectively), with LVESVI (r = 0.34, p < 0.01 and r = 0.56, p < 0.001, respectively) and with LVEDVI (r = 0.28, p < 0.01 and r = 0.44, p < 0.001, respectively). The maximal WBC count also correlated with LVEF and LVESVI (r = -0.40, p < 0.001 and r = 0.21, p < 0.05, respectively). Conclusion - The present study revealed that the circulating WBC count correlated with function and volume of the successfully reperfused LV after AMI in patients with the same risk area for AMI, indicating that the WBC count needs to be taken into consideration as an independent factor affecting the LV indices.