Methods and Results:Optical coherence tomography (OCT) of SVG lesions in consecutive patients presenting with stable CAD and ACS was carried out. Thirty-nine patients (32 de novo and 10 ISR lesions) were included in the registry. ISR occurred in 5 BMS and 5 DES. There were no differences in the presence of plaque rupture and thrombus between de novo lesions and ISR. Lipid-rich tissue was identified in both de novo lesions and in ISR (75% vs. 50%, P=0.071) with a higher prevalence in BMS than in DES (23% vs. 7.5%; P=0.048). Calcific de novo lesions were detected in older grafts as compared with non-calcific atheromas (159±57 vs. 90±62 months after CABG, P=0.001). Heterogeneous neointima was found only in ISR (70% vs. 0, P<0.001) and was observed with similar frequency in both BMS and DES (24% vs. 30%, P=0.657). ISR was detected earlier in DES than BMS (median, 50 months; IQR, 18–96 months vs. 27 months; IQR, 13–29 months, P<0.001).