Optical coherence tomography (OCT) is an established medical imaging technique that uses light to capture high-resolution, three-dimensional images of blood vessels. These images will be used before and after implanting the stent in the main blood vessel. Fractional Flow Reserve (FFR) test, which makes it possible for the interventional cardiologist to calculate blood flow across an area of a coronary artery, will be done after stenting and will help to determine if there are any changes in the side branch blood flow.