Assessment of culprit plaque temperature by intracoronary thermography appears inconclusive in patients with acute coronary syndromes.

OBJECTIVE Safety and feasibility evaluation of intracoronary temperature measurements in patients with acute coronary syndromes (ACS) using a catheter based thermography system. METHODS AND RESULTS Thermography was performed in 40 patients with ACS. A 3.5-F thermography catheter containing 5 thermocouples measuring vessel wall temperature, and 1 thermocouple measuring blood temperature (accuracy 0.05 degrees C) was used. Gradient (deltaTmax) between blood temperature (T(bl)) and the maximum wall temperature during pullback was measured. The device showed satisfactory safety in ACS. Only in 16 patients (40%) deltaTmax was > or = 0.1 degrees C. In 23 patients (57.5%) the highest deltaTmax was found in the culprit segment. DeltaTmax between culprit and adjacent non-culprit segments was observed in patients with transient blood flow interruption during thermography (0.11+/-0.03 versus 0.08+/-0.01; P=0.04), in contrast to patients with preserved flow (0.07+/-0.03 versus 0.06+/-0.02; P=0.058). CONCLUSIONS The novel, technically sophisticated intracoronary thermography proved its safety and feasibility. However, we were not able to convincingly and consistently differentiate between different lesions at risk, despite a selection of lesions that should appear most distinct to differentiate. A systematic interruption of flow may be necessary to achieve diagnostic results consistently, although such requirement may unfavorably change the risk-to-benefit ratio of this developing technology.