Early rhythm control in patients with atrial fibrillation and cancer: A subgroup analysis of the EAST-AFNET 4 trial

Background and Aims Early rhythm-control improves cardiovascular outcomes in patients with atrial fibrillation (AF). Its effectiveness in patients with cancer is unclear. This study evaluated the effects of cancer history on early rhythm-control in the EAST-AFNET 4 trial. Methods This secondary analysis of EAST-AFNET 4 compared patients with and without a history of cancer, including active cancer and cancer in remission. Outcomes included the primary outcome, a composite of cardiovascular death, stroke, or hospitalization for worsening heart failure or acute coronary syndrome; the safety outcome, a composite of death, stroke, and serious adverse events related to rhythm-control; and rhythm at 24 months. Results Cancer history was available in 2779/2789 patients (99.6%). Cancer history was present in 216/2779 (7.8%; 19 with active cancer; mean age, 73 years; 95 [44%] women; mean CHA2DS2-VASc score, 3.5). During a follow-up to 8.6 years, early rhythm control reduced the primary outcome in patients with and without a history of cancer (pinteraction = .23) with high rates of sinus rhythm at 24 months (cancer: 84.9%, without cancer: 81.8%; pinteraction = .60). In patients with a cancer history, there was a signal for more safety outcomes with early rhythm control (early rhythm control 36/116 [31%] patients with event, 22 deaths; usual care 20/100 [20%] patients with event, 18 deaths; pinteraction = .055). Conclusions Early rhythm control therapy appears effective in patients with AF and a history of cancer but may be less safe than in patients without cancer, in this hypothesis-generating analysis. This could be play of chance but warrants further research into the safety and efficacy of rhythm control therapy in patients with a cancer history.