ABSTRACT
Significantly it is also possible for small calibre catheters to engage the coronary artery beyond a significant aorta-ostial stenosis. Both right and left main ostial lesions may be overlooked with this approach. The distal anatomy may appear suitable for percutaneous intervention but it is only when a larger (6 French or more) guiding catheter is introduced that ostial disease is then apparent, perhaps making this approach inappropriate.
