Increased local temperature in human coronary atherosclerotic plaques: an independent predictor of clinical outcome in patients undergoing a percutaneous coronary intervention

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 (ΔT) 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 ΔT increased progressively from EA to AMI (0.132 ± 0.18°C in EA, 0.637 ± 0.26°C in UA and 0.942 ± 0.58°C in AMI). The median clinical follow-up period was 17.88 ± 7.16 months. The ΔT was greater in patients with adverse cardiac events than in patients without events (ΔT: 0.939 ± 0.49°C vs. 0.428 ± 0.42°C; p < 0.0001). The ΔT was a strong predictor of adverse cardiac events during the follow-up period (odds ratio 2.14, P = 0.043). The threshold of the ΔT value, above which the risk for an adverse cardiac event was significantly increased, was 0.5°C. The incidence of adverse cardiac events in patients with ΔT ≥0.5°C was 41%, as compared with 7% in patients with ΔT <0.5°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.