There are several results that are possible after undergoing cardiac catheterization (angiogram of the blood vessels of the heart).
The best result is that there are no critical blockages detected by the test. The chest pain and/or abnormal test results are not related to significant blockages in the arteries supplying blood to the heart. One of the most serious causes of the clinical findings has been ruled out with essentially 100% certainty. It would be like a cancer doctor telling you the good news that you do not have cancer.
The second result is that there is a significant blockage that was fixed with balloon angioplasty and stent placement. This allows you to go home the next day in most cases and avoid surgery. The procedure is usually done immediately after the angiogram by the interventional cardiologist.
Sometimes more than one blockage can be fixed during the same procedure, but generally the “culprit” lesion is intervened on and other less critical lesions are left for a different time. This is because of limits to the amount of contrast you can receive (which is harmful to the kidneys) and the amount of radiation you can get in one procedure.
The third result is that you have blockages that are not amenable to balloon angioplasty/stent placement. The blockages can be in areas that are too risky to fix or in a vessel that is too small. They may also be in non-critical areas and the risks outweigh the benefits. Additionally, an artery that is chronically 100% blocked cannot be opened without some increased risk to the patient.
The last result is that you have blockages that can only be fixed with bypass surgery. Generally (although not always) this is not an emergency. You recover normally from your angiogram and the cardiologist and cardiovascular surgeon will discuss with you the merits of performing bypass surgery versus continuing medical therapy.
There may be variations of the above outcomes, but these represent the most common findings/outcomes after an angiogram is done.