Coronary CTA examination has corresponding risks. In general, the risks of coronary CTA examination include the risk of contrast agent, which can cause laryngeal edema, anaphylactic shock and other symptoms in severe cases, and can even lead to death. In addition, the contrast agent is excreted through the kidneys, which may aggravate pre-existing renal insufficiency and lead to a dramatic deterioration in renal function. In general, the risks of coronary CTA examinations are manageable. First of all, before doing the examination, the basic status of renal function should be clarified, and the situation related to the medication should be clarified. For patients with severe renal insufficiency, it is recommended to avoid relevant examinations. In addition, for taking metformin and other drugs before the test, attention needs to be paid to postpone the time of the test. In addition, after the examination, attention should be paid to adequate hydration, as well as the avoidance of allergic factors before the examination, you can use glucocorticoids and other drugs to prevent the occurrence of allergies.