Canadian Cardiovascular Society (CCS): staging of stable angina pectoris.
| CCS stage | Definition |
| 0 | Silent ischemia (reduced blood flow) without any symptoms (= no restriction of physical activity)Angina pectoris only during severe, rapid or sustained exertion |
| I | Symptomatology only with severe physical exertion (= mild limitation of physical activity)Angina pectoris when walking or climbing stairs at increased speed or after meals,walking more than 100 m or climbing stairs more than 1 floor at normal speedwalking uphill, cold, emotional stress |
| II | Minor discomfort with normal physical activity (= marked limitation of physical activity)Angina pectoris on walking less than 100 m or after climbing stairs of 1 floor at a normal rate |
| III | Angina pectoris even with mild physical exertion or already at rest |
| IV | Angina pectoris on any physical exertion or already at rest |
Classification of unstable angina (UA)
| Severity | Clinical situation | ||
| Class A | Class B | Class C | |
| Class I: new-onset severe or worsening angina pectoris (AP), no resting AP. | IA | IB | IC |
| Class II: resting AP in the past month but not in the past 48 h (subacute AP). | IIA | IIB | IIC |
| Class III: resting AP within the past 48 h (acute resting AP). | IIIA | IIIC | |
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