Influence of atrial fibrillation subtypes on anticoagulant therapy in a high-risk older population: the FAI project

Background and aim: Benefits of oral anticoagulants (OAC) in atrial fibrillation (AF) patients with moderate-to-high risk of stroke are independent of AF pattern. We evaluated whether AF clinical subtype influenced OAC use in a representative sample of the Italian older population.

Methods: A cross-sectional examination of all subjects aged 65 + years from three general practices in northern, central, and southern Italy started in 2016. A double-screening procedure was followed by clinical and ECG confirmation. Patients were categorized as having paroxysmal, persistent, or permanent AF. OAC use was evaluated in confirmed AF patients.

Results: The sample included 6016 subjects. Excluding 235 non-eligible, participation was 78.3%, which left 4528 participants (mean age 74.5 ± 6.8 years, 47.2% men). Overall, 319 AF cases were identified: 43.0% had paroxysmal, 21.3% persistent, and 35.7% permanent AF. Frequency of OAC therapy was 91.2% in permanent, 85.3% in persistent, and only 43.0% in paroxysmal AF (P < 0.001). In multivariate analysis, controlled for baseline variables and risk scales, persistent and permanent AF were associated with a significant increase in the likelihood of receiving OAC compared with paroxysmal AF (P < 0.001). This was confirmed for permanent AF also in multivariate analyses considering separately vitamin K antagonists or direct-acting oral anticoagulants (OR, 4.37, 95% CI, 2.43-7.85; and 1.92, 95% CI, 1.07-3.42, respectively) and for persistent AF and direct-acting oral anticoagulants (OR, 4.33, 95% CI, 2.30-8.15).

Conclusions: In a population-based survey, AF pattern was an independent predictor of OAC treatment. Paroxysmal AF is still perceived as carrying a lower risk of vascular events.