Revascularization: Bypass Surgery and Angioplasty

Ischemic heart disease is the commonest form of heart illness. It increases in frequency with increasing age, and outcomes are much worse in elderly patients. Ischemia is caused by narrowings or blockages in the coronary arteries, resulting in an inadequate blood supply to the heart. The disease spectrum ranges from subclinical disease (no symptoms) to angina, and, finally, to a heart attack (myocardial infarction, or MI). Typical angina is marked by exertional chest pain and shortness of breath that settles with rest. With stable angina, people may limit their activities to avoid symptoms, but it is generally well-tolerated and can be controlled with medication.

With acute ischemic syndromes, which include both unstable angina and myocardial infarctions, the risks are much greater. Unstable angina is marked by an increase in the severity or duration of pain or symptoms—and having them occur with lower levels of activity or at rest. If unstable angina progresses in a crescendo pattern, it may lead to a myocardial infarction. With a myocardial infarction, the ischemia to the heart is so severe that permanent damage occurs to the muscle. Major complications from heart attacks include life-threatening arrhythmias, congestive heart failure, and death.

Mortality rates from myocardial infarction for patients younger than sixty-five are generally less than 5 percent, while mortality rates for those over the age of seventy-five are greater than 20 percent.

There are six medications used to treat ischemic heart disease. Aspirin, cholesterol-lowering medications, and ACE inhibitors all reduce the risk of future heart attacks and strokes but have no other effect on the symptoms of angina. Beta blockers help reduce the symptoms of angina and the risk of heart attacks and strokes. Calcium channel blockers and nitroglycerin also help control Figure 1 The Heart: Coronary Arteries with Bypass SOURCE: Suggested by brochure issued by Pfizer Canada Inc. (1996) and created by Symphony Medical Communications of Oslo, Norway (1996). symptoms of angina. As patients get older, especially diabetics and women, they are more likely not to have typical chest pain and angina, which can lead to misdiagnosis.