Heat production of atherosclerotic plaques and inflammation assessed by the acute phase proteins in acute coronary syndromes

Several studies have shown that inflammation plays an important role in the pathogenesis of coronary heart disease (CHD), Serum amyloid A (SAX) and C- reactive protein (CRP) reactants of the acute phase of inflammation, have b een shown to be increased in patients with CHD. Recently ex vivo studies de monstrated that some types of atherosclerotic plaques show substantially wa rmer regions. A catheter-based technique has been developed to measure the temperature of human arteries in vivo. Therefore, the aim of the present st udy was to measure the luminal surface temperature in patients with CHD and to correlate it with the acute phase proteins in order to discriminate the role of inflammation in heat production in acute coronary syndromes. Sixty patients were studied with CHD (20 with stable angina, 30 with unstab le angina and 20 with acute myocardial infarction) and 20 sex- and age-matc hed controls without coronary artery disease, by measuring plasma levels of SAA, CRP, plasma lipids and intracoronary arterial luminal wall temperatur e. Intracoronary temperature was measured with a thermography catheter deve loped in our Institution: a thermistor probe with a temperature accuracy of 0.05 degrees C, was attached at the distal end of a long 3F polyurethane s haft. It was found that the median temperature differences at the site of the les ion from the core temperature was increased in patients with unstable angin a (1.025 degrees C) and acute myocardial infarction (2.150 degrees C) compa red with stable angina (0.300 degrees C), P<0.001 for each comparison. Furt hermore, stable angina has increased temperature differences compared with controls (0.200 degrees C, P<0.001), There were very good correlations bet between CRP and SAA with the temperature (r = 0.796, P = 0.01 and r = 0.848 , P = 0.01, respectively). Local heat at the site of lesion is increased in patients with acute corona ry syndromes and may arise from an aggressive inflammatory response occurri ng in these situations. The sensitive measurement of plaque temperature as a prognostic marker map be useful in the management of coronary heart disea se. (C) 2000 Academic Press.