Risk Stratification In Patients With Chronic Myocardial Ischemia

Available methods for risk stratification in CAD patients Clinical parameters ECG Chest x-ray Noninvasive testing –Resting LV function –Exercise test –Stress imaging Coronary angiography Gibbons RJ et al.

High-risk criteria Severe resting LV dysfunction (LVEF <35%) High-risk treadmill score (≤-11) Severe exercise LV dysfunction (LVEF <35%) Stress-induced large perfusion defect (esp anterior) Multiple, moderate-sized perfusion defects Large, fixed perfusion defect with LV dilation or increased lung uptake (thallium-201) Stress-induced moderate perfusion defect with LV dilation or increased lung uptake (thallium-201) Echocardiographic wall motion abnormality (>2 segments) at low dobutamine dose (≤10 mg/kg per min) or low HR (<102 bpm) Stress echocardiographic evidence of extensive ischemia Gibbons RJ et al. >3% annual mortality rate

Intermediate-risk criteria Mild/moderate resting LV dysfunction (LVEF 35%-49%) Intermediate-risk treadmill score (-11 < score < 5) Stress-induced moderate perfusion defect without LV dilation or increased lung intake (thallium-201) Limited stress echocardiographic ischemia with a wall motion abnormality only at higher doses of dobutamine involving ≤2 segments 1%-3% annual mortality rate Gibbons RJ et al.

Low-risk criteria Low-risk treadmill score (≥5) Normal or small myocardial perfusion defect at rest or with stress Normal stress echocardiographic wall motion or no change of limited resting wall motion abnormalities during stress Gibbons RJ et al. <1% annual mortality rate

Comparison of 3 different risk scores de Araújo Gonçalves P et al. Eur Heart J. 2005;26: N = 460 consecutive patients with NSTE-ACS 30 days 1 year Death or MI (%) PURSUIT risk scoreGRACE risk scoreTIMI risk score < > < > Death/MI:

Summary Chronic IHD continues to impose a high socioeconomic burden Mechanistic understanding has undergone a paradigm shift –Traditional focus: Determinants of myocardial O 2 supply/demand –Contemporary focus: Changes in Na + and Ca 2+ currents during ischemia Contemporary management: –Aggressive treatment of multiple risk factors –Multifactorial treatment of symptoms Renewed interest in the role of optimal medical therapy vs PCI