In patients treated with aspirin, intermittent atrial fibrillation was associated with a similar annualized rate of ischemic stroke (3.2%) compared to sustained atrial fibrillation (3.3%).
Cohort (n=2,012)
Does intermittent atrial fibrillation carry a similar risk of ischemic stroke compared to sustained atrial fibrillation in patients treated with aspirin?
Patients with intermittent AF have stroke rates similar to those with sustained AF, indicating that high-risk patients with intermittent AF should be considered for anticoagulation.
Absolute Event Rate: 3.2% vs 3.3%
OBJECTIVE: This study was performed to characterize the risk of stroke in elderly patients with recurrent intermittent atrial fibrillation (AF). BACKGROUND: Although intermittent AF is common, relatively little is known about the attendant risk of stroke. METHODS: A longitudinal cohort study was performed comparing 460 participants with intermittent AF with 1,552 with sustained AF treated with aspirin in the Stroke Prevention in Atrial Fibrillation studies and followed for a mean of two years. Independent risk factors for ischemic stroke were identified by multivariate analysis. RESULTS: Patients with intermittent AF were, on average, younger (66 vs. 70 years, p < 0.001), were more often women (37% vs. 26% p < 0.001) and less often had heart failure (11% vs. 21%, p < 0.001) than those with sustained AF. The annualized rate of ischemic stroke was similar for those with intermittent (3.2%) and sustained AF (3.3%). In patients with intermittent AF, independent predictors of ischemic stroke were advancing age (relative risk RR = 2.1 per decade, p < 0.001), hypertension (RR = 3.4, p = 0.003) and prior stroke (RR = 4.1, p = 0.01). Of those with intermittent AF predicted to be high risk (24%), the observed stroke rate was 7.8% per year (95% confidence interval 4.5 to 14). CONCLUSIONS: In this large cohort of AF patients given aspirin, those with intermittent AF had stroke rates similar to patients with sustained AF and similar stroke risk factors. Many elderly patients with recurrent intermittent AF have substantial rates of stroke and likely benefit from anticoagulation. High-risk patients with intermittent AF can be identified using the same clinical criteria that apply to patients with sustained AF.
Hart et al. (2000) conducted a cohort in Atrial fibrillation (n=2,012). Intermittent atrial fibrillation vs. Sustained atrial fibrillation was evaluated on Ischemic stroke. In patients treated with aspirin, intermittent atrial fibrillation was associated with a similar annualized rate of ischemic stroke (3.2%) compared to sustained atrial fibrillation (3.3%).