Atrial Fibrillation (AF) is often associated with underlying heart failure (HF), valvular disease, ischemic heart disease, as well as other structural heart diseases, but can occur as an independent entity: AF alone. We aimed to assess, on a national scale, the prognosis of patients hospitalised with AF alone and AF associated with cardiac disease.

All consecutive patients with AF admitted to hospital between 2010 and 2018 were included; i.e. 2,793,234. Patients were identified in the French administrative hospital discharge database.

Overall, most patients had developed AF with cardiac disease (n=2,127,803; 76.18%). At follow-up (median [IQR] 1.1 [0.1–3.4] years), patients with AF and CD had an increased risk of all-cause death (yearly incidence: 13,6% vs. 9%; [RR (95% CI)]: [1.51 (1.50–1.52)]; P<0.00001], and CV death (4.4% vs. 1.9%; [RR 2.33 (2.30–2.36)]; P<0.00001). Likewise, in propensity score matched population, (median [IQR] 1.9 [0.3–4.4] years), patients with AF and CD also had worse outcomes than patients with AF alone (all-cause death: 10.6% vs. 7.4% [RR 1.43 (1.42–1.45)], P<0.00001; CV death rates: 3.3% vs. 2% [RR 1.64 (1.61–1.68)], P<0.00001); Nonetheless, a well-marked difference was highlighted, the RR for ischemic stroke varied considerably between the 2 groups and higher in the AF lone group (1.69% vs. 2.75%; OR 0.62, 95% CI 0.60–0.63; P<0.00001).

In this large study of patients hospitalised with AF obtained from a nationwide database, we identified two distinct clinical entities that could explain the results highlighted. Firstly, the consistency in terms of mortality in the group with atrial fibrillation associated with underlying heart disease and independently, patients suffering atrial fibrillation alone, for which the major prognosis must focus on the thromboembolic problem, which may have therapeutic implications.