Thrombolytic therapy is the use of drugs to break up or dissolve blood clots, which are the main cause of both heart attacks and stroke.
Thrombolytic medications are approved for the immediate treatment of stroke and heart attack. The most commonly used drug for thrombolytic therapy is tissue plasminogen activator (tPA), but other drugs can do the same thing.
According to the American Heart Association, you have a better chance of surviving and recovering from certain types of heart attacks if you receive a thrombolytic drug within 12 hours after the heart attack starts.
Ideally, you should receive thrombolytic medications within the first 30 minutes after arriving at the hospital for treatment.
A blood clot can block the arteries to the heart. This can cause a heart attack, when part of the heart muscle dies due to a lack of oxygen being delivered by the blood.
Thrombolytics work by dissolving a major clot quickly. This helps restart blood flow to the heart and helps prevent damage to the heart muscle. Thrombolytics can stop a heart attack that would otherwise be deadly.
The drug restores some blood flow to the heart in most patients. However, the blood flow may not be completely normal and there may still be a small amount of muscle damaged. Additional therapy, such as cardiac catheterization or angioplasty, may be needed.
Your health care provider will base the decisions about whether to give you a thrombolytic medication for a heart attack on many factors. These factors include your history of chest pain and the results of an ECG test.
Other factors used to determine if you are a good candidate for thrombolytics include:
- Age (older patients are at increased risk of complications)
- Medical history (including your history of a previous heart attack, diabetes, low blood pressure, or increased heart rate)
Generally, thrombolytics will not be given if you have:
- A recent head injury
- Bleeding problems
- Bleeding ulcers
- Recent surgery
- Taken blood thinning medications such as Coumadin
- Uncontrolled (severe) high blood pressure
Most strokes are caused when blood clots move to a blood vessel in the brain and block blood flow to that area. For such strokes (ischemic strokes), thrombolytics can be used to help dissolve the clot quickly. Giving thrombolytics within 3 hours of the first stroke symptoms can help limit stroke damage and disability.
The decision to give the drug is based upon:
- A brain CT scan to make sure there has not been any bleeding
- A physical exam that shows a significant stroke
- Your medical history
As in heart attacks, a clot-dissolving drug isn't usually given if you have one of the other medical problems listed above.
Thrombolytics are not given to someone who is having a hemorrhagic stroke (a hemorrhagic stroke means there has been bleeding in the brain). They could worsen the stroke by causing increased bleeding.
There are various drugs used for thrombolytic therapy, but tPAs are used most often. Other drugs include:
- Streptokinase (SK)
Alternatives to thrombolytic therapy include interventional therapies done via catheters, such as balloon angioplasty (PTCA) with or without stenting, and thrombectomy (removing the clot).RISKS
Hemorrhage or bleeding is the most common risk. It can be life threatening.
Minor bleeding from the gums or nose can occur in approximately 25% of people who receive the drug. Bleeding into the brain occurs approximately 1% of the time. This risk is the same for both stroke and heart attack patients.
CONTACT A HEALTH CARE PROVIDER OR CALL 911
Heart attacks and strokes are medical emergencies. The sooner treatment with thrombolytics begins, the better the chance for a good outcome.
Tissue plasminogen activator; TPA; Alteplase; Reteplase; Tenecteplase; Activase thrombolytic agent; Clot-dissolving agents; Reperfusion therapy
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Update Date 5/13/2014
Updated by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.