Thrombolytic Therapy (Tissue Plasminogen Activator - TPA)

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Heart attack

According to the American College of Cardiology (ACC), each year 800,000 persons in the United States have acute heart attacks and 213,000 die. Those who die from heart attacks generally die within 1 hour from the initial onset of symptoms and sometimes before they get to the hospital.

Guidelines are used to determine if someone is a good candidate for using tPA. Many national groups are working together to decrease the time it takes to get people having a heart attack to facilities where tPA can be given. The sooner thrombolytic therapy is given, the better the outcome. The window of opportunity is a very short amount of time.

For a person having an acute heart attack, tPA works by dissolving a major clot quickly. The clot is most likely blocking one of the coronary arteries that normally allows blood and oxygen get to the heart muscle.

By dissolving the clot, the blood is able to start flowing again to that area of the heart. If the blood flow to the heart is started again rapidly, it may prevent long-term damage to the heart muscle and may even stop an event that could have been fatal.

The drug is successful in restoring some blood flow to the heart muscle in approximately 75% of patients, but the resultant blood flow may not be entirely normal. Further therapy, such as cardiac catheterization, may be needed.

Physicians base their decisions about whether to give tPA for a heart attack on many factors, including a history of chest pain and the results of an ECG test.

Other factors used to determine if someone is a good candidate for tPA include age, medical history, gender, history of previous heart attack, history of diabetes, history of low blood pressure, or increased heart rate, and if the person is elderly (older than 70 years).

Generally, tPA will not given if the person has had a recent head injury, trauma, surgery, bleeding problems, uncontrolled high blood pressure, bleeding ulcers, or pregnancy.