LOS ANGELES – Strokes in patients with atrial fibrillation have long-term consequences.
Patients with atrial fibrillation (AF) who had an ischemic stroke and survived for the first 30 days following the event still had a greater than threefold increased risk of death during the following 5 years, compared with AF patients who had no stroke, in a retrospective study.
"The effects of stroke on mortality in patients with atrial fibrillation persist far beyond the initial event," Dr. Margaret Fang said at the International Stroke Conference.
Dr. Margaret Fang
The findings also highlight the importance of using proper anticoagulation regimens in patients with AF, both to prevent strokes and to reduce the severity of the strokes that do occur.
"We talk about preventing in-hospital death and 30-day mortality" with anticoagulation treatment of patients with AF, "but by preventing stroke, we also reduce long-term mortality. And if strokes occur, they are milder, and milder strokes have better long-term mortality outcomes," Dr. Fang, a hospitalist and director of the anticoagulation clinic at the University of California, San Francisco, said in an interview.
Her study reviewed 13,559 patients with nonvalvular AF (average age, 71 years) who were enrolled in Kaiser Permanente of Northern California. At baseline, about 9% of the patients had a history of a prior stroke. During a median follow-up of 6 years, 1,025 patients had a new-onset ischemic stroke.
About half of the patients were on warfarin at baseline. During follow-up, the incidence of stroke was 1.2% per year among patients on warfarin and 2.0% per year in patients not on warfarin. Warfarin treatment also led to milder strokes: About 46% of the warfarin-treated patients who had a stroke had either no deficit or only minor sequelae from their stroke, compared with 39% in patients not on warfarin. Major or severe deficits or death occurred in 54% of those on warfarin and in 61% of those not receiving anticoagulant treatment. The 30-day mortality rate was 20% in patients on warfarin at the time of their stroke and 28% in those not on warfarin.
The mortality among AF patients who survived longer than 30 days after their stroke was a statistically-significant 3.4-fold higher than in AF patients who did not have a stroke, according to an analysis that controlled for age, sex, prior stroke, and comorbidities such as hypertension and diabetes. At the 5-year follow-up, more than 70% of the AF patients without a stroke remained alive, compared with fewer than 40% of patients who had a stroke during the study period.
Survival beyond 30 days after a stroke also depended on stroke severity. About 60% of patients without disability following their stroke were alive at 5 years. Patients with strokes that produced minor, major, or severe deficits had 5-year survival rates of roughly 50%, 30%, and 10%, respectively.
Dr. Fang said that she had no disclosures.