OBJECTIVES:We investigated the midterm clinical significance of human coronary atherosclerotic plaques temperature after a successful percutaneous coronary intervention. BACKGROUND:Previous studies have shown an increased temperature in human atherosclerotic plaques. However, the prognostic significance of atherosclerotic plaque temperature in patients undergoing a successful percutaneous intervention is unknown. METHODS:We prospectively investigated the relation between the temperature difference (deltaT) between the atherosclerotic plaque and the healthy vessel wall and event-free survival among 86 patients undergoing a successful percutaneous intervention. Temperature was measured by a thermography catheter, as previously validated. The study group consisted of patients with effort angina (EA) (34.5%), unstable angina (UA) (34.5%) and acute myocardial infarction (AMI) (30%). RESULTS:The deltaT increased progressively from EA to AMI (0.132 +/- 0.18 degrees C in EA, 0.637 +/- 0.26 degrees C in UA and 0.942 +/- 0.58 degrees C in AMI). The median clinical follow-up period was 17.88 +/- 7.16 months. The deltaT was greater in patients with adverse cardiac events than in patients without events (deltaT: 0.939 +/- 0.49 degrees C vs. 0.428 +/- 0.42 degrees C; p < 0.0001). The deltaT was a strong predictor of adverse cardiac events during the follow-up period (odds ratio 2.14, p = 0.043). The threshold of the deltaT value, above which the risk for an adverse cardiac event was significantly increased, was 0.5 degrees C. The incidence of adverse cardiac events in patients with deltaT > or = 0.5 degrees C was 41%, as compared with 7% in patients with deltaT < 0.5 degrees C (p < 0.001). CONCLUSIONS:Increased local temperature in atherosclerotic plaques is a strong predictor of an unfavorable clinical outcome in patients with coronary artery disease undergoing percutaneous interventions.