Comparison of lumen area after PTCA by IVUS and QCA

The coronary lumen area just after percutaneous transluminal coronary angioplasty (PTCA) was assessed by intravascular ultrasonography (IVUS) with 4.3 F cardiovascular imaging systems (CVIS) and quantitative coronary angiography (QCA) with Kontron CARDIO 500. Altogether 34 lesions were divided into two groups by IVUS findings using Nissen's circular shape factor (CSF), which was defined by the (calculated perimeter/observed perimeter), expressing lumen eccentricity. The eccentric group (CSF < or = 0.92) was 22, and concentric group (CSF > 0.92) was 12. The minimum lumen diameter by IVUS and QCA (both edge-detection and densitometric methods) correlated in both the eccentric and concentric groups. As for the lumen area, only the QCA densitometric method in the concentric group correlated with the lumen area determined by IVUS. Despite using QCA, it is almost impossible for angiography to determine the lumen area just after PTCA if an eccentric lesion with a tear or dissection had occurred.