Perspective: Is thrombolytic therapy for stroke the standard of care?

The so-called “clot busting” drugs for treatment of heart attacks were heavily marketed and quite widely used for the past 10-20 years. They remain useful in circumstances where better options are not available. However, in the past 10 years evidence has mounted that the best option is percutaneous transluminal coronary angioplasty (PTCA), available only in large hospitals with an on-call interventional cardiologist and a cath lab.

For the past 10 years, pharmaceutical manufacturers of tPA and similar clot-busting drugs have been heavily marketing them for the treatment of stroke. But the questions of when these drugs work and when the risk exceeds the benefit are still being debated. And, for a variety of reasons, few patients actually qualify for treatment. Estimates under 5% are common.

Readers should consider the following points considered by physicians when evaluating a patient for thrombolytic (clot-busting) treatment of stroke:

1. The treatment is not without risk. The major risk is intracerebral hemorrhage and death.
2. When did the stroke occur? When was the patient last seen “normal?” If it occurred during sleep, a common presentation, the patient is usually ineligible.
3. The drugs work best when given within 3 hours of onset of symptoms? Six hours is an outside time limit.
4. Can the workup for stroke be done quickly? Is the hospital actually capable of providing the treatment? If a CT or MRI scan of the brain cannot be completed within the time frame for administration of drug, the patient cannot receive the drug.
5. What contraindications exist? Has the patient had recent surgery or stroke? Is the patient already on blood thinners? Is the blood pressure too high?
6. Is it really a stroke? Many “transient ischemic attacks” or TIAs resolve in a short period of time. Many other problems mimic stroke. Treating either of these with a thrombolytic drug has a poor risk-benefit ratio, and often can be fatal.
7. Is the patient and family willing to accept the risk? Even in well-selected patients who meet the criteria for receiving the drug, there is a real risk of making the stroke worse or causing death. Truly informed consent is critical.

Readers may then wish to check out the following articles illustrating the current situation.

1. For a positive view of thrombolytic therapy, a good overview, and a long list of references, check out this article in EMedicine.  (Note that two of the authors have ties to pharmaceutical manufacturers.)
2. The American Academy of Emergency Medicine has authored a cautionary policy statement on the use of thrombolytic therapy for stroke.
3. The Canadian Association of Emergency Physicians has also produced a very restrictive policy statement on the issue, emphasizing that the decision to treat be made within 3 hours of onset of symptoms by a neurologist in a “stroke-ready” specialty center with proper imaging capability and governmental research oversight.
4. An editorial in Stroke arguing in favor of tPa for stroke can be found here. However, even this author, a consultant to Genentech, agrees that, while tPA is 10 times more likely to help than harm the patient, at least 3.4% of patients will be made worse by treatment.

Medical malpractice attorneys are seeing increasing numbers of claims in this area. They are rarely as clear-cut as they may seem at first blush. There are several highly respected academic physicians who provide expert testimony on both sides of the issue in cases where giving or not giving thrombolysis for stroke is the issue. Given the above, this situation may be viewed by the uninitiated as a win-win for plaintiff attorneys. A thorough review of each specific situation by a physician well-versed in recent evidence for and against the emergency treatment of stroke is mandatory.

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