Evidence of prolonged inflammation in unstable angina and non–Q wave myocardial infarction

OBJECTIVES This study was designed to document the inflammatory response up to one year after acute presentation with unstable angina (UA) and non–Q wave infarction (NQMI) as reflected by the expression of soluble cell adhesion molecules (CAMs). BACKGROUND Coronary plaque inflammation is a key component in the pathogenesis of acute coronary syndromes. Cell adhesion molecules are critical mediators of the inflammatory process. Soluble forms of these molecules are detectable in serum and are elevated acutely in patients with UA and NQMI. METHODS Patients presenting with UA and NQMI had serum samples taken at presentation and then after three, six and 12 months. A control group of similar age and gender distribution was used for comparison. Levels of soluble inter-cellular adhesion molecule-1, vascular cell adhesion molecule-1, endothelial-selectin and platelet-selectin were measured using an ELISA technique. RESULTS We studied 91 patients (M/F = 73/18, mean age 62 ± 11 years, 56 UA and 35 NQMI) and 24 controls (M/F = 18/6, mean age 56 ± 12 years). Levels of all four soluble CAMs were significantly elevated in both UA and NQMI patients at presentation, three and six months in comparison with controls. Levels in UA and NQMI groups fell between six and 12 months after initial presentation. CONCLUSIONS The results suggest that the inflammatory stimulus triggering expression of CAMs is sustained for up to six months after presentation with either UA or NQMI and then returns toward control values over the following six months.