Stroke Prevention: Recommendations

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 Is Contraindicated

  • 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 anticoagulation.
  • 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 disease.
  • 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 Endarterectomy (CE)

  • 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 stroke.

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 Unless Contraindicated

  • 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:

Publications Clearinghouse
P.O. Box 8547
Silver Spring, MD 20907
800-358-9295 (24 hours a day)

Page last reviewed September 1995
Internet Citation: Stroke Prevention: Recommendations: Research Findings for Clinicians. September 1995. Agency for Healthcare Research and Quality, Rockville, MD.