Post-Reperfusion Enhancement of CD14+CD16- Monocytes and Microvascular Obstruction in ST-Segment Elevation Acute Myocardial Infarction

Background: The presence of microvascular obstruction (MVO) after primary ST-segment elevation acute myocardial infarction (STEMI) is associated with a poor outcome. The aim of the paper was to examine the relationship between distinct monocyte subsets and gadolinium-enhanced cardiovascular magnetic resonance (CMR) characteristics of MVO after STEMI. Methods and Results: Seventy-one patients with primary STEMI successfully treated with stenting were enrolled in the study. Two monocyte subsets (CD14+CD16- and CD14+CD16+) were measured on flow cytometry on admission and 2, 3, 4, 5, 8 days after the onset of STEMI. CMR was performed 7 days after revascularization to determine MVO on late gadolinium-enhanced imaging. The peak levels of CD14+CD16- monocytes, but not those of CD14+CD16+ monocytes, were significantly higher in patients with MVO than in those without MVO. A multivariate logistic regression model showed that the post-perfusion peak levels of CD14+CD16- monocytes remained an independent factor for the presence of MVO (odds ratio=1.53; 95% confidence interval: 1.01-2.32; P=0.04). The absence of MVO was significantly associated with improvement in left ventricular ejection fraction. Conclusions: Post-reperfusion enhancement of CD14+CD16- monocytes was associated with MVO in patients with STEMI. The pathophysiologic and therapeutic implications of this association require further study. (Circ J 2010; 74: 1175 - 1182)