INTRODUCTIONMyocardial infarction (MI) is common and affects a significant number of people annually. Death occurs due to either arrhythmia or heart failure. As leucocytosis, especially elevated neutrophil count, is a hallmark of inflammatory reactions in patients with MI, we investigated the relationship between leucocytosis on admission and left ventricular ejection fraction (LVEF) in patients with acute MI (AMI).

METHODSPatients with AMI were enrolled in a case-control study. Blood samples obtained in the first 24 hours after the onset of pain were analysed for cardiac enzyme levels and cell count. Echocardiography was performed on Days 3-5. Patients with LVEF < 45% were assigned to the left ventricular (LV) systolic dysfunction group (n = 69) and those with LVEF ≥ 45% were taken as controls (n = 69). All patients were matched for variables such as hypertension, diabetes mellitus, hyperlipidaemia, family history of cardiac disease, age and gender.

RESULTSLeucocytosis was higher in patients with systolic dysfunction (47.8%) when compared with the controls (20.3%), and was significantly associated with the development of LV systolic dysfunction (p = 0.001). Similarly, neutrophilia was more common in patients with systolic dysfunction than the controls (6.6% vs. 34.8%), and was significantly associated with LV systolic dysfunction (p < 0.001). Monocytosis was higher in the controls than the systolic dysfunction group (40.6% vs. 33.3%; p = 0.378).

CONCLUSIONLeucocytosis and neutrophilia in the acute phase of MI are important predictive factors for the development of LV systolic dysfunction. Leucocytosis can be used for risk stratification of such patients.