Pharmacological rhythm control strategy and outcomes in the oldest atrial fibrillation patients: an analysis of the nationwide Italian START registry.

BACKGROUND

Evidence on antiarrhythmic drugs (AADs) in the oldest atrial fibrillation (AF) patients is limited. We investigated clinical characteristics and outcomes associated with AADs use in this population.

METHODS

The oldest (age ≥ 80 years) AF patients from the nationwide START registry were included. Patients were divided into three groups: no AADs (n = 3573), class 1c-AADs (n = 207) and Amiodarone (n = 464). Factors associated with AADs were evaluated using multivariable logistic regression models. The associations between AADs and all-cause mortality were assessed using Cox proportional hazards models and cardiovascular events (CVEs) were analysed using Fine-Gray competing risk models.

RESULTS

Among 4244 patients (54.9% women), the mean age was 84.8 ± 3.8 years. AADs were prescribed in 671 patients (15.8%), including amiodarone in 464 (10.9%) and 1c-AADs in 207 (4.9%). 1c-AADs use was associated with younger age and fewer comorbidities, including lower prevalence of diabetes, heart failure, chronic obstructive pulmonary disease/obstructive sleep apnoea and better functional and social status. Amiodarone use was associated with coronary artery disease and markers of frailty. Over a median follow-up of 502 (interquartile range 362-857) days, 492 deaths and 548 CVEs occurred. In unadjusted analyses, 1c-AADs were associated with lower all-cause mortality and CVEs; however, these associations were no longer significant after multivariable adjustment. Amiodarone use was not associated with clinical outcomes in either unadjusted or adjusted analyses.

CONCLUSION

In the oldest AF patients, AADs use is influenced by comorbidity burden and frailty-related characteristics. AADs were not independently associated with mortality or CVEs, suggesting that pharmacological rhythm control may be reserved for selected cases in this population.