Assessment Of Coronary Lesions By Optical Coherence Tomography

Objectives 1. To compare the diagnostic accuracy of optical coherence tomography (OCT) and intravascular ultrasound (IVUS) in the detection of coronary plaque with different composition and coronary lesions (thrombus, dissection,neointima) ex vivo as compared with histology.2. Use OCT to investigate the relationship between the morphology of plque rupture and thrombosis. Use OCT to assess the stent edge dissections and its related factors. To compare the ability of OCT and IVUS for assessment of coronary plaques and lumen dimension in patients with coronary heart diseases.Methods 1. Comparison with IVUS and histology. OCT and IVUS was performed in 15 heart specimens and then the isolated coronary artery was assessed by routine histological processing. To analyse the sensitivity and specificity for assessment of different plaques by OCT and IVUS and compared with histology. To observe the differences in assessment of coronary lesions(thrombus,dissection) and neointima by OCT and IVUS.2. Clinical study. (1) 20 patients with plaque rupture in coronary artery detected by OCT divided into 2 groups (with or without thrombus) and to investigate the relationship between the morphology of plaque rupture and thrombosis.(2)To assess the incidence of stent edge dissections and the factors related with it in 42 patients performed OCT after stenting, (3) To compare OCT and IVUS for assessment of coronary plaques and measurement of lumen dimension in 17 patients performed OCT and IVUS simultaneously.Results 1. OCT demonstrated a sensitivity and specificity of 69/88% for lipid-rich plaque,93/92% for calcified plaque, and 88/98% for fibrous plaque as compared with histology. IVUS demonstrated a sensitivity and specificity of 61/92%,98/97%, 68/90% respectively. There was good agreement of the thickness of neointima between OCT and histology((218.33±132.12μm vs 213.69±143.68μm,p=0.69).2. (1) The thickness of the fibrous cap of ruptured plaque with thrombus was significantly thiner than that without thrombus(57.00±18.00μm vs 99.00±50.00μm (p=0.0140).(2) Incidence of stent edge dissections detected by OCT was 21%, Stent edge expansion and stent expansion were both higher in group with dissectons than those in group without dissections ((1.682±0.425 vs 1.229±0.285, p=0.0290; 1.507±0.445 vs 1.174±0.265,p=0.0072). (3) OCT and IVUS demonstrated good agreement in assessment of different plaques (K=0.50, P<0.01). The lumen area measured using OCT was smaller than that measured using IVUS (3.06±1.026mm2 vs 3.78±0.99 mm2, p=0.0374) and area stenosis obtained by OCT is higher than that by IVUS (0.54±0.15 vs 0.44±0.15, p=0.0151).Conclusions 1. OCT demonstrated good agreement in assessment of different plaques with IVUS and histology. 2. The thickness of fibrous cap of ruptured plaque without thrombus was thicker than those with thrombus. 3. Stent edge dissections is related with stent edge expansion and stent expansion. 4. There is a significantly difference in measurement of lumen area and area stenosis between OCT and IVUS.