Stroke-Preventive Drug Underused
Dec. 20, 1999 (Atlanta) -- Erring on the side of caution, most doctors fail to give patients with atrial fibrillation a drug that can greatly reduce their risk of stroke. A new study shows that four out of 10 eligible patients still don't get the drug, although it does show HMOs that offer doctors better support can increase proper treatment.
Atrial fibrillation is a condition in which the heart tends to beat out of rhythm. There are several types of treatment, but patients remain at high risk of stroke. A blood-thinning drug marketed as warfarin sodium or Coumadin greatly reduces this risk, but doctors often are reluctant to prescribe it.
"We are actually encouraged, in part, by our findings, because in the rest of the country only a third of patients are getting it," the lead author of the study, Alan S. Go, MD, tells WebMD. "More work needs to be done to improve its use. Patients with atrial fibrillation should at least consult with their doctor to see if they're candidates to take it."
The Anticoagulation and Risk Factors in Atrial Fibrillation Study (ATRIA) analyzed patients enrolled in the Kaiser Permanente Medical Care Program in northern California. The over 11,000 patients eligible for warfarin therapy during the study period had one or more risk factors for stroke. Only 59% of these patients received warfarin therapy. Even among patients considered ideal candidates -- aged 65-74 years with heightened risk due to previous stroke, hypertension, or both -- only 62% received the drug.
"We don't know the exact reasons why patients were not placed on warfarin therapy, except for patients who refused and patients with underlying risk [of adverse effects]," Go says. "Even with that limitation, it is unlikely that explains all the eligible patients who were not receiving warfarin."
Randall S. Stafford, MD, PhD, and Daniel Singer, MD, have studied national patterns of warfarin use in atrial fibrillation. They found that during the 1980s, when the drug's stroke-reduction benefits first became known, use increased greatly -- to as many as 40% of eligible patients -- but then leveled off. In an interview to provide objective comment, Stafford tells WebMD that physician reluctance to provide warfarin stems from fear of doing harm.