Research Findings for Clinicians
The Secondary and Tertiary Prevention of Stroke Patient
Outcomes Research Team (PORT) has established important findings
about the most cost-effective treatments for people at high risk
for stroke. The PORT is a 5-year research study supported by the
Agency for Health Care Policy and Research (AHCPR). These
findings have led to the following recommendations for the
treatment of patients with atrial fibrillation (select Figure 1: algorithm for atrial fibrillation [15 KB]) and transient
ischemic attack (TIA)/minor stroke (select Figure 2: algorithm for TIA/minor stroke [26 KB]).
Patients with Atrial Fibrillation
Prescribe Warfarin Unless Risk of Stroke Is Low or Use
- Anticoagulant treatment is particularly effective for
patients with atrial fibrillation and any one of the
following additional risk factors: over age 60, prior
stroke, diabetes, hypertension, and heart disease.
- Aspirin may be used if warfarin is contraindicated,
unless aspirin also is contraindicated.
Use Good Anticoagulation Monitoring Techniques
- Avoid overanticoagulation, which is associated with a
higher risk of bleeding complications.
- Monitor patients every 2-3 days at the beginning of
warfarin therapy until International Normalized Ratio
(INR) is stabilized (range: 2-3). When stabilized,
monitor at least every 2 months.
- Check patients within 7 days after beginning or ending
medication known to affect warfarin response.
- Consult drug interaction tables. Many classes of drugs
such as antibiotics and anticonvulsants (e.g.,
phenobarbital and Tegretol) can interfere with
- If possible, refer patient to an anticoagulation service
for ongoing monitoring.
Patients with Transient Ischemic Attack/Minor Stroke
If Symptoms Suggest Transient Ischemic Attack or Stroke
- Determine if symptoms are consistent with carotid
- If uncertain of diagnosis, refer to a neurologist.
- If symptoms are consistent with carotid disease, evaluate
with noninvasive tests and/or angiography for presence
and degree of stenosis.
If Carotid Disease Is Confirmed, Consider Carotid
- CE is most cost-effective for treatment of patients with
high-grade stenosis (greater than 70-percent blockage)
and TIA or minor stroke.
- CE is not cost-effective for patients with low-grade
stenosis (less than 30-percent blockage) or those without
other signs or symptoms consistent with high risk for
If CE Is Indicated, Send Surgical Candidates to Surgeons
and Hospitals with Low Rates of Complications for CE
- There is wide variation in surgical risk, depending on
surgeon, operating team, and hospital.
- Hospitals should be encouraged to monitor complication
rates for CE to promote informed decisionmaking by
patients and referring physicians.
Treat Nonsurgical Candidates with Aspirin or Ticlopidine
- Patients on aspirin should use an enteric-coated variety
that is less likely to be associated with
gastrointestinal side effects.
- Patients on ticlopidine should have a neutrophil count
according to manufacturer directions.
These recommendations are drawn from Secondary and Tertiary
Prevention of Stroke Patient Outcomes Research Team: Seventh
Progress Report: March 31, 1995, David B. Matchar, MD,
Principal Investigator, at Duke University's Center for Health
Policy Research and Education.
Printed copies of Stroke Prevention: Recommendations are available by writing or calling:
P.O. Box 8547
Silver Spring, MD 20907
800-358-9295 (24 hours a day)
AHCPR Publication No. 95-0091
Current as of September 1995
Stroke Prevention: Recommendations. Research Findings for Clinicians. Fact sheet. Agency for
Health Care Policy and Research, Rockville, MD. http://www.ahrq.gov/clinic/strokcln.htm