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

D. Ismaili (Hamburg)¹, A. Suling (Hamburg)², K. Borof (Hamburg)², A. Goette (Paderborn)³, G. Breithardt (Münster)⁴, J. Camm (London)⁵, H. Crijns (Maastricht)⁶, L. Eckardt (Münster)⁷, A. Elvan (Braunschweig)⁸, L. Fabritz (Hamburg)¹, K. Wegscheider (Hamburg)⁹, S. Willems (Hamburg)¹⁰, A. Zapf (Hamburg)², A. Metzner (Hamburg)¹¹, A. Rillig (Hamburg)¹¹, P. Kirchhof (Hamburg)^12
1Universitäres Herz- und Gefäßzentrum Klinik für Kardiologie Hamburg, Deutschland; ²Universitätsklinikum Hamburg Eppendorf Hamburg, Deutschland; ³St. Vincenz-Krankenhaus GmbH Medizinische Klinik II, Kardiologie Paderborn, Deutschland; ⁴Münster, Deutschland; ⁵St. Georges Hospital Cardiovascular Research Group London, Großbritannien; ⁶University of Maastricht Maastricht, Niederlande; ⁷Universitätsklinikum Münster Klinik für Kardiologie II - Rhythmologie Münster, Deutschland; ⁸Klinikum Braunschweig Rhythmologie Braunschweig, Deutschland; ⁹Universitätsklinikum Hamburg-Eppendorf Zentrum für Experimentelle Medizin, Institut für Medizinische Biometrie und Epidemiologie Hamburg, Deutschland; ¹⁰Asklepios Klinik St. Georg Kardiologie & internistische Intensivmedizin Hamburg, Deutschland; ¹¹Universitäres Herz- und Gefäßzentrum Klinik für Kardiologie mit Schwerpunkt Elektrophysiologie Hamburg, Deutschland; ¹²Universitätsklinikum Hamburg-Eppendorf Klinik für Kardiologie Hamburg, Deutschland

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. 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%; mean age, 73 years; 95 [44%] women; mean CHA₂DS₂-VASc score, 3.5). During a follow-up to 5.1 years, early rhythm control reduced the primary outcome in patients with and without a history of cancer (p_interaction = .23) with high rates of sinus rhythm at 24 months (cancer: 84.9%, without cancer: 81.8%; p_interaction = .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; p_interaction = .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 calls for further research into the safety and efficacy of rhythm control therapy in patients with a cancer history.