Thrombolytic therapy (aka clot-busting therapy) is medication widely used to treat patients who come to the Emergency Department with a myocardial infarction, or heart attack. When used correctly, it is a life-saving therapy to quickly open up a clogged artery that would normally supply blood and oxygen to the heart muscle, and preserve muscle that would otherwise die.
Coronary artery disease refers to damage to the major blood vessels supplying the heart, known as the “coronary arteries.” Deposits known as plaque that contain cholesterol may damage these vessels. As the plaques begin to increase in size, the coronary arteries become narrowed and this results in diminished blood flow to the heart. If the plaques reach a critical size, the decreased blood flow will cause chest pain that is also known as angina. Patients with coronary artery disease may also experience shortness of breath or fatigue with activity.
When the plaque completely blocks an artery, it results in a heart attack or myocardial infarction. (Infarction refers to death; myocardial refers to the muscular tissue of the heart.)
Some risk factors for coronary artery disease include smoking, hypertension, high cholesterol, diabetes and a sedentary lifestyle. The process begins with damage or some injury to the inner layer of the coronary artery, with accumulation of fatty plaques at the site of the injury. This process is also known as atherosclerosis.
When one of these plaques ruptures, platelets (blood cells that cause a clot by forming clumps at the site of tissue injury) will adhere to the ruptured plaque and block the artery. The interruption of blood flow that results from this process can result in damage or complete destruction of a portion of the heart.
Prompt treatment of a heart attack is necessary to prevent death of the heart muscle. The treatment for this process is removal of the blockage in the coronary artery that is affected. This can be done either by taking the patient to the catheterization laboratory and performing angioplasty, or by utilizing a “clot-busting” drug like tPA.
Thrombolytic drugs are normally used when there is no time to get the patient to the catheterization lab, such as in cases where there is not an interventional cardiologist available. The earlier this occurs, the better the prognosis, and the standard of care for patients who present to an Emergency Department with a heart attack is to receive a clot-busting drug within 30 minutes of reaching the door (“door-to-drug”).
Increased Risk of Bleeding
Although these drugs are real lifesavers, they do result in increased risk of bleeding. Evidence supports administration of thrombolytics to patients with a particular type of ECG pattern known as an “ST elevation myocardial infarction” with symptom onset within 12 hours, if there is no ability to have a percutaneous coronary intervention (cath lab) within 120 minutes of presentation.
Clot-busting therapy should not be given to certain patients where the risk of bleeding is greater than the benefit of therapy. This includes patients with previous intracranial hemorrhages, any known cerebral vascular lesion or intracranial tumor, a history of a “dry” stroke within 3 months, suspicion of an aortic dissection, any active bleeding, or a history of significant facial or closed-head trauma within 3 months.
Such conditions (among others) carry a higher risk of the most feared complication of thrombolytic therapy, which is an intracranial hemorrhage. These occur most frequently within 24 hours of thrombolysis, and represent 0.5-1% of cases. An intracranial hemorrhage caused by thrombolytics is fatal is as often as 80% of cases. Some baseline risks include age greater than 65 years; weight less than 70 kilograms, hypertension and female gender.
Bleeding resulting in transfusion occurs in approximately 5% of patients. Hemorrhagic stroke may occur in 1.8% of patients who receive thrombolytic therapy with the addition of aspirin and intravenous heparin.
Recent complications in the news as a result of failure to observe contraindications to thrombolytic therapy in the treatment of a heart attack have resulted in large monetary settlement for wrongful death or morbidity as the result of intracranial hemorrhage. If you or a loved one has experienced a complication of thrombolytic therapy, such as an intracranial hemorrhage, then you should consult a Chicago medical malpractice attorney at Passen Law Group for a review of a potential cause of action. Call us at 312-527-4500.