Exercise Capacity (METs)

Patents with a poor exercise capacity (<4 METs) represent a high-risk subset, especially if ischemic ECG changes are noted at this low workload. Conversely, patients with a good exercise capacity (>10 METs) often have an excellent prognosis independent of the extent of anatomical CAD. It is estimated that for every 1 met increase in exercise capacity the survival improved by 12%. Failure to reach 85% of predicted exercise capacity was significantly associated with increased risk of MI, unstable angina, coronary revascularization as well as mortality. The association with nonfatal cardiac events suggests that poor exercise capacity is not simply a reflection of a greater burden of comorbidities and worse patient health status.