Impact of rhythm control strategy on outcomes in patients with first diagnosed atrial fibrillation in an 11-year real-world registry

Abstract Background Atrial fibrillation (AF) is a highly prevalent arrhythmia with a high burden of disease. This sub-study of the Heidelberg Registry of Atrial Fibrillation (HERA-FIB) sought to evaluate clinical characteristics, treatment strategies and outcomes in patients with first diagnosed AF (FDAF). Methods Patients with AF presenting to the emergency department (ED) of an University Hospital between June 2009 and March 2020 were consecutively enrolled. Follow-up was performed for all-cause mortality, stroke, major bleeding and myocardial infarction (MI). Outcomes were were related to patients with FDAF or pre-existing AF, as well as assigned treatement strategy (rhythm vs. rate control). The trial was registered at ClinicalTrials.gov Identifier: NCT05995561. Results Overall 2,758 (27%) of all patients presented with FDAF. Compared to FDAF, patients with pre-existing AF showed higher all-cause mortality HR 1.41 (95%CI 1.28-1.55, p<0.0001) and major bleeding events 1.29 (95% CI 1.06-1.56, p=0.0098). Non-implementation of rhythm control in FDAF was seen in 2,079 cases (75.4%) and was associated with an excess of all-cause mortality HR 1.66 (95%CI 1.30-1.99, p<0.0001) and incident MI HR 1.79 (95% CI 1.03-3.09, p=0.0385). A non-implementation of rhythm control remained an independent predictor for all-cause mortality and MI even after adjustment for significant univariate variables aHR: 1.34 (95%CI: 1.04-1.72, p=0.0234) and aHR: 1.79 (95%CI: 1.03-3.09, p=0.0385). Conclusion Real-world data from FDAF patients presenting in the setting of an ED showed a potential benefit regarding mortality and MI for rhythm control strategy. Further research is needed to validate this hypothesis.