Initiating rhythm control early lowers CV risk in recently diagnosed AF patients: Study
Korea: Early initiation of rhythm control treatment in patients with recently diagnosed atrial fibrillation (AF) lowers the risk of adverse CV outcomes versus rate control treatment, according to a recent study in the journal BMJ. However, this does not hold true for patients who had atrial fibrillation for more than one year.
The findings suggest that the favorable effects of rhythm control over rate control might be due to the inclusion of patients with early AF, and to maximize its efficacy the earlier initiation of rhythm control treatment is needed.
Atrial fibrillation patients are at increased risk of mortality and morbidity from congestive heart failure, stroke, and impaired quality of life, even for those with optimal anticoagulation and rate control treatment. Rate control is important for AF management and is often sufficient for improving related symptoms.
Rhythm control refers to attempts to restore and maintain sinus rhythm using antiarrhythmic drug treatment, cardioversion, and atrial fibrillation ablation together with adequate rate control. Such treatment improves symptoms and the quality of life of patients
Daehoon Kim, Yonsei University College of Medicine, Seoul, Republic of Korea, and colleagues aimed to investigate whether the results of a rhythm control strategy differ according to the duration between diagnosis of atrial fibrillation and treatment initiation.
For this purpose, the researchers designed a longitudinal observational cohort study. The population-based cohort were extracted from the Korean National Health Insurance Service database. It included 22 635 adults with atrial fibrillation and cardiovascular conditions, newly treated with rhythm control (antiarrhythmic drugs or ablation) or rate control strategies between 28 July 2011 and 31 December 2015.
The primary outcome of the study was a composite outcome of death from cardiovascular causes, ischaemic stroke, admission to hospital for heart failure, or acute myocardial infarction.
Of the study population, 53.9% were male, the median age was 70, and the median follow-up duration was 2.1 years.
Key findings of the study include:
- Among patients with early treatment for atrial fibrillation (initiated within one year since diagnosis), compared with rate control, rhythm control was associated with a lower risk of the primary composite outcome (weighted incidence rate per 100 person-years 7.42 in rhythm control v 9.25 in rate control; hazard ratio 0.81).
- No difference in the risk of the primary composite outcome was found between rhythm and rate control (weighted incidence rate per 100 person years 8.67 in rhythm control v 8.99 in rate control; 0.97) in patients with late treatment for atrial fibrillation (initiated after one year since diagnosis).
- No significant differences in safety outcomes were found between the rhythm and rate control strategies across different treatment timings.
- Earlier initiation of treatment was linearly associated with more favorable cardiovascular outcomes for rhythm control compared with rate control.
"Within one year since the diagnosis of atrial fibrillation, initiating rhythm control as early as possible was associated with more favorable cardiovascular outcomes than with rate control," wrote the authors.
"These results suggest that the favorable effects of rhythm control over rate control seen in the EAST-AFNET 4 trial might be attributable to the inclusion of patients with early atrial fibrillation, and initiation of rhythm control treatment earlier is needed to maximize the efficacy," they concluded.
Reference:
The study titled, "Treatment timing and the effects of rhythm control strategy in patients with atrial fibrillation: nationwide cohort study," is published in the journal BMJ.
DOI: https://www.bmj.com/content/373/bmj.n991
