Macrophage colony stimulating factor (MCSF) is a haematopoietic growth factor released by the injured endothelium and can stimulate proliferation, differentiation, and maturation of monocytes and macrophages.1 MCSF stimulates the synthesis of monocyte chemotactic protein 1 and increases the adhesion of monocytes to endothelium. In addition, MCSF has been located in atherosclerotic lesions of humans and it has been proposed that it may contribute to the progression of atherosclerosis.

Elevation of MCSF has also been reported in unstable angina but few data exist regarding the prognostic value.2 In the present study we evaluated whether admission concentrations of MCSF can predict prognosis in patients hospitalised with unstable angina.

We studied 122 patients (96 men and 26 women) aged 59 (10) years (range 38–75 years) admitted to our coronary care unit with severe unstable angina. Inclusion criteria were angina at rest with at least two attacks or one episode lasting > 20 minutes in the previous 24 hours with newly developed ⩾ 0.1 mV ST segment depression in two or more contiguous leads. There was no elevation of creatine kinase (CK) on admission or six hours later. Exclusion criteria were recent myocardial infarction (< 3 months), coronary artery bypass graft, age > 75 years, …