Additional Study Information: The purpose of this study is to compare the safety and effectiveness of an approved medical device (OCT) which will be used to help select and guide the stenting procedure by collecting images and flow measurements inside the blocked arteries in comparison to both standard angiography and another medical device (IVUS). Coronary Artery Disease is the narrowing or blockage of the coronary arteries, usually caused by the build-up of cholesterol and fatty deposits in the walls of the arteries. This blockage can slow down the blood flow carrying oxygen and vital nutrients to the heart and in turn cause chest pain. A Coronary Angiogram shows an image of the coronary arteries and is used to check where in the arteries there is a blockage. A stent can then be implanted in the blocked arteries to help open them up.