Myocardial Ischemia: Concepts in Management

1. Myocardial Ischemia: Concepts in Management Topics in Clinical Medicine February 14, 2007

2. Familiar Concepts • Determinants of myocardial ischemia • Making the diagnosis – clinical and laboratory investigation • Prognosis should determine treatment

3. Historical Notes Errors in judgment must occur in the practice of an art which consists largely in balancing probabilities. Sir William Osler, 1882 The capacity to make effective use of today’s diagnostic…technology depends in large measure on the accuracy with which the physician can perceive the dangers to the patient at that particular moment…The ability to forecast with reasonable accuracy is one of the most important things a doctor can do. Walsh McDermott, 1982

4. Prognosis in Chronic Ischemic Heart Disease Death TRANSITION ZONE Severity A B STEMI NSTEMI UAP SCA C Time in Years

5. Familiar Concepts • Determinants of myocardial ischemia • Determinants of myocardial oxygen supply • Oxygen-carrying capacity • Coronary flow • Determinants of myocardial oxygen demand • Heart rate • Wall tension (~ systolic pressure) • Contractility

6. Familiar Concepts • Determinants of myocardial ischemia • Making the diagnosis – clinical and laboratory investigation • Typical angina (definite) • Substernal discomfort, quality, duration • Provoked by exertion or emotion • Relieved by rest or TNG • Atypical angina (probable) – 2 of above • Non-specific chest pain – 1 or none

7. Pretest Likelihood of CAD Non-Specific Atypical Typical

8. Pretest Likelihood of CAD at Catheterization Non-Specific Atypical Typical

9. Familiar Concepts • Determinants of myocardial ischemia • Making the diagnosis – clinical and laboratory investigation • Prognosis should determine treatment Duke Treadmill Score Time in minutes = - 5 x mm ST depression = 0 = none - 4 x angina index 1 = angina, not limiting 2 = limiting angina Total score =

10. Why do we treat angina? • Prevent Death • Prevent MI • Reduce Symptoms • ASA and Anti-anginal Therapy • Beta-blocker and Blood Pressure • Cigarette Smoking and Cholesterol • Diet and Diabetes • Education and Exercise

11. New Concepts • Unusual presentations • Acute treatment in myocardial infarction – how and where to open the artery • Secondary prevention after myocardial infarction • Women

12. MI - Secondary Prevention • BP control (<140/90; <130/80 if diabetes or renal failure; pre-hypertension) • Lipids – LDL < 100, (optional < 70) but statin in all; If TG 200-499 – bring non-HDL cholesterol to < 130 – fibrate** or niacin; If TG >500, use fibrate** or niacin first, then treat LDL; ** watch for myopathy – keep statin dose low • Beta-blocker • Anti-platelet therapy – ASA 75-162 (325 x 1 month if stent); clopidogrel 75 mg/d • ACEi; ARB, esp if intolerant • Aldosterone blockade if EF <40%, DM, CHF

13. MI - Secondary Prevention • Smoking Cessation • Diet - <7% saturated fat, <200 mg cholesterol, stanol/sterol, viscous fiber, fish • Physical Activity – 30 min 7/wk • Weight management – waist circumference • Diabetes control – HbA1c < 7

15. How to Keep Up • Online – e.g., Harrison’s Online • Guidelines – specialty societies • www.americanheart.org

16. Classification of Recommendations and Levels of Evidence Size of Treatment Effect Estimate of Certainty (Precision) of Treatment Effect