The role of rhythm control in patients with first diagnosed atrial fibrillation in a real world collective
Authors: Milles B , Yildirim M , Hund H , Biener M , Mueller-Hennessen M , Frey N , Katus H A , Giannitsis E , Salbach C 
Published: May 2024

Abstract

Funding Acknowledgements
Type of funding sources: Private company. Main funding source(s): Daiichi Sankyo Bayer.

Background
There has been conflicting evidence regarding the importance of rhythm control as opposed to rate control in patients with atrial fibrillation (AF). Thus, no clear recommendation on early rhythm control for risk reduction is given in the current guidelines. However, some evidence suggests that rhythm control is superior to rate control in patients with a recent diagnosis of AF.

Purpose
We aim to characterize patients with first diagnosed AF and evaluate the effect of a rhythm control strategy at the time of diagnosis on long term cardiovascular outcomes.

Methods
This is a single center, retrospective observational sub study based as a part of the HERA-FIB project. HERA-FIB included 10.222 patients presenting to the emergency department (ED) of the department of cardiology of a university hospital from June 2009 to March 2020. We consecutively included all patients with a history AF or current AF upon presentation, regardless of the reason for presentation. A structured follow-up regarding survival and major cardiovascular events was performed. Mean follow up was 23 months (IQR 12-35). Patient care was not influenced. The project was performed according to the declaration of Helsinki and was approved by the local ethics committee and registered at ClinicalTrials.gov (Identifier: NCT05995561). Results. After adjudication we included 10.222 patients in this study. Of those 2758 (27%) had no previous history of AF and were first diagnosed with AF upon presentation. There were major differences in baseline characteristics as patients with first diagnosed AF were younger (73 years vs 76 years, p&lt;0.0001), showed a normal left ventricular function more often (47.9% vs 40.2%, p&lt;0.0001) and had fewer histories of coronary artery disease (CAD) (30.2% vs 48.0%, p&lt;0.0001) and fewer histories of stroke or transient ischemic attack (TIA) (9.0% vs 14.0%, p&lt;0.0001). In contrast they had higher heart rates (113 bpm vs 84 bpm, p&lt;0.0001) on admission. Among the patients with first diagnosed AF 24.6% received a cardioversion (either pharmacological of electrical). Patients with first diagnosed AF undergoing rhythm control treatment showed lower rates for all-cause mortality (10.4% vs 18.2%, p&lt;0.0001) and myocardial infarction (2.4% vs. 5.2%, p=0.0045) as compared to patients first diagnosed with AF not recieving a cardioversion. However, no differences for strokes (2.7% vs 3.3%, p=0.6158) or severe bleeding according to ISTH major bleeding criteria (4.0% vs. 5.3%, p=0.2252) could be detected.

Conclusions
Patients presenting to an ED with first diagnosed AF are younger and show fewer comorbidities compared to patients with pre-existing AF. Patients with first diagnosed AF seem to profit from early rhythm control strategies showing a reduction for the rates of all-cause mortality and myocardial infarction. However, no difference for stroke or major bleeding events could be detected. Additional, prospective studies are required to verify this hypothesis.