BACKGROUND Although early rhythm control (ERC) is effective in reducing stroke in patients with atrial fibrillation (AF), its benefits have not been well elucidated in cancer survivors. This study aimed to compare the risk of ischemic stroke between ERC and usual care in cancer survivors with AF.

METHODS This nationwide observational study was conducted using the Korean National Health Insurance Service database. Patients aged ≥20 years with newly diagnosed AF between 2009 and 2018 were included. Patients who received rhythm control therapy within 1 year of AF diagnosis were defined as the ERC group, while the remaining patients were defined as usual care group. The risk of ischemic stroke in the ERC group was compared with those of the usual care group in cancer survivors (cancer diagnosis ≥5 years) and the noncancer group.

RESULTS A total of 591 692 patients were included in the study (18 747 patients [3.2%] with cancer; mean age, 65.7±14.6 years; 53.7% men). During a mean 4-year follow-up, stroke occurred in 52 500 patients (1338 cancer survivors and 51 182 noncancer survivors). The ERC group showed a lower risk of stroke than the usual care group, regardless of the presence of a cancer history (adjusted hazard ratio, 0.67 [95% CI, 0.58-0.76] in cancer survivors versus 0.76 [95% CI, 0.74-0.78] in the noncancer group).

CONCLUSIONS ERC is associated with a lower risk of ischemic stroke among cancer survivors. An integrated approach that incorporates appropriate rhythm control strategies should be considered for cancer survivors with newly diagnosed AF.