Chronic stable angina pectoris: Guidelines

Areas of Uncertainty
Some patients who are not candidates for coronary revascularization continue to have severe or limiting angina; almost all have multivessel coronary artery disease and have previously undergone revascularization and have target vessels that are not suitable for the procedure (because they are distal, diffuse, or of small caliber). The optimal approach to management of these cases remains uncertain. One option is the use of enhanced external counterpulsation; results of a sham-controlled, randomized trial, as well as observational data, suggest that this form of therapy decreases the severity and frequency of angina, although objective reductions in ischemia have been variable. Another approach is transmyocardial laser revascularization, in which multiple laser channels are made directly into the myocardium. Both procedures are approved by the Food and Drug Administration (FDA), although the mechanisms by which they relieve angina remain uncertain. The role of promising new agents, including trimetazidine and ranolazine, that alter myocardial metabolism is currently unclear with regard to the treatment of angina; neither drug has received FDA approval.

Guidelines
The 1999 guidelines on stable angina, revised in 2002, of the American College of Cardiology, the American Heart Association, and the American College of Physicians, represent the most comprehensive available treatise on chronic stable angina. The American College of Cardiology-American Heart Association guidelines on coronary-artery bypass grafting, updated in 2004, are also useful. Recent National Cholesterol Education Program-Adult Treatment Panel III guidelines support aggressive lipid lowering in patients with chronic stable angina. All recommendations in this review are consistent with those guidelines.

Summary and Conclusions
The diagnosis of chronic stable angina is made on the basis of anginal symptoms, a noninvasive stress test that is positive for myocardial ischemia, and documentation of coronary Atherosclerosis on angiography. Antianginal drugs should be prescribed in effective doses, usually beginning with a beta-blocker; aspirin is mandatory. Management should routinely include lifestyle modifications, including smoking cessation, weight control, and regular exercise, and aggressive control of other cardiovascular risk factors. Drugs to slow the progression of atherosclerosis, including statins and, in many cases, ACE inhibitors, are also indicated. The target LDL cholesterol level in persons with chronic stable angina is below 100 mg per deciliter (2.6 mmol per liter); in high-risk patients, the level is 60 to 70 mg per deciliter. Angiography is generally indicated if symptoms continue despite treatment with antianginal medications or if high-risk features appear on stress testing. I would recommend this, along with the other interventions described above, in a case such as that described in the vignette. Revascularization should be considered for persons with class II and III symptoms, a high risk as determined by diagnostic tests, or angina that the patient finds unacceptable despite medical management.