[Dr. Rhine responds:]

Letters

CJEM 2001;3(1):5-6

I agree with Drs. Gubitz and Phillips¹ that tPA is one small part of a "systems approach" to stroke treatment. I also agree that more patients will benefit from stroke units and ASA because the vast majority of stroke victims are eligible for these, while only a small number currently receive tPA. The importance of the Cleveland paper² is to emphasize that the risks of tPA may be higher in community hospitals than in research settings. I also intended to infer that, in community hospitals, stroke patients may benefit more from stroke teams, stroke units and other potentially less injurious interventions, such as ASA.

The CAEP Position Statement on "Thrombolytic Therapy for Acute Ischemic Stroke," published in this issue³ of CJEM, agrees with my interpretation of the evidence and suggests that stroke thrombolysis should be limited to centres with rapid 24-hour access to specialized neurological expertise and neuro-imaging resources. Requirements suggested in the document, along with the currently recognized 3-hour time barrier from symptom onset, effectively limit stroke thrombolysis to tertiary care centres (which provide a minority of emergency medical care in Canada). Practitioners in non-tertiary centres must be aware of the risks and limitations of stroke thrombolysis so that they can provide their patients with the best local standard of care and "do no harm."

Gubitz and Phillips correctly point out that low molecular weight heparins (LMWH) are unlikely to benefit patients with acute stroke. Although one study⁴ showed impressive results in this setting, these results have not been replicated elsewhere, and a recent Cochrane Review (published after the CJEM Journal Club article went to press) concluded that, although LMWH appears to decrease the occurrence of deep vein thrombosis, there are too few data to provide reliable information on their effect on other important outcomes, including death and intracranial hemorrhage.⁵

The Cleveland study demonstrates that outcomes achieved in research settings may not be reproducible in all settings. Until such time as community-based effectiveness studies demonstrate safety, emergency physicians should remain skeptical. In the wrong hands, tPA may cause more harm than good for acute stroke victims.

D.J. Rhine, MD
Chairman
Department of Emergency Medicine
King Faisal Specialist Hospital
& Research Center
Riyadh, Saudi Arabia

References

1. Gubitz G, Phillips S. Intravenous tPA for acute stroke [letter]. CJEM 2001;3(1):5.
2. Rhine D. Intravenous tPA for acute stroke: Any and all hospitals? Any and all strokes? CJEM 2000;2(3):189-91.
3. Canadian Association of Emergency Physicians Committee on Thrombolytic Therapy for Actue Ischemic Stroke. Thrombolytic therapy for acute ischemic stroke [position statement]. CJEM 2001;3(1):8-12.
4. Kay R, Wong KS, Yu YL, Chan YW, Tsoi TH, Ahuja AT, et al. Low-molecular-weight heparin for the treatment of acute ischemic stroke. N Engl J Med 1995;333:1588-93.
5. Counsell C, Sandercock P. Low-molecular-weight heparins or heparinoids versus standard unfractionated heparin for acute ischaemic stroke. Cochrane Database of Systematic Reviews 2000;2:CD000119.