The ccs classification is a grading standard for exertional angina developed by the Canadian Cardiovascular Society. This standard has been widely used in clinical practice, and its specific contents are as follows: 1, Grade I general daily activities will not cause angina, and only at a faster speed and with more exertion will cause an attack of angina; 2, Grade II daily physical activities are slightly restricted, and only after meals or when emotionally excited, can cause angina; 3, Grade III daily physical activities are obviously restricted, and even with Walking under normal conditions or going up a flight of stairs can cause an attack of angina; 4. Grade 4 can be caused by light activity, even when resting. In general, the grading correlates with the degree of blood vessel blockage. For patients with grades 2, 3 and 4, undergoing coronary stenting is a better option.