A trial fibrillation (AF) is the most common cardiac arrhythmia in developed countries and increases the risks for stroke, heart failure, and death.1 Until 2 decades ago, the incidence and risk factors for stroke were less well characterized in patients with paroxysmal AF (PAF) when compared with those with persistent or permanent AF.2,3 Since then, several studies have reported that patients with PAF have a risk of thromboembolic events that was similar to that in persistent or permanent AF. [4][5][6][7] In accordance with the results from these studies, current guidelines worldwide recommend the use of oral anticoagulant (OAC) for the prevention of thromboembolism, irrespective of the type of AF. [8][9][10] However, more recent studies have reported that the patients with PAF had a lower rate of stroke/systemic embolism (SE).
11-13Also, patients with PAF are less likely to receive OAC therapy in the real-world clinical practice.6,14 However, limited data on stroke risk associated with PAF are evident in Asian populations with PAF because most studies were epidemiological studies on Western populations or selected clinical trial cohorts.Background and Purpose-There is controversy on the relationship of the type of atrial fibrillation (AF) to stroke.Although several studies show that patients with paroxysmal AF (PAF) have a stroke risk similar to those with persistent or permanent AF, recent studies suggest that PAF is associated with a lower rate of stroke. Limited data on stroke risk associated with PAF are evident in Asian populations.
Methods-The Registry Study of Atrial Fibrillation Patients in Fushimi-ku (Fushimi AF Registry) is a community-basedsurvey of patients with AF in Fushimi-ku, Kyoto, Japan. Patients were categorized into 2 types of AF: PAF or sustained (persistent or permanent) AF. We compared clinical events between PAF (n=1588) and sustained AF (n=1716). Results-Patients with PAF were younger, had less comorbidities, and received oral anticoagulants (OAC) less commonly.A lower risk of stroke/systemic embolism during follow-up period in the patients with PAF was consistently observed (non-OAC users: hazard ratio, 0.45; 95% confidence intervals, 0.27-0.75; P<0.01 and OAC users: hazard ratio, 0.59; 95% confidence interval, 0.35-0.93; P=0.03). The composite end point of stroke/systemic embolism/all-cause mortality was also lower in PAF, whether among OAC users (hazard ratio, 0.77; 95% confidence interval, 0.59-0.99; P=0.046) or non-OAC users (hazard ratio, 0.59; 95% confidence interval, 0.46-0.75; P<0.01). On multivariate analysis, PAF was an independent predictor of lower stroke/systemic embolism risk. Conclusions-In this large cohort of Japanese patients with AF, PAF was independently associated with lower incidence of stroke/systemic embolism than sustained AF. This may aid decision making for anticoagulation, especially in those patients with AF with few stroke risk factors.
Clinical Trial Registration
