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03-04-2024 | Atrial Fibrillation | News

Antiarrhythmic drugs linked to increased pacemaker implantation or syncope risk

Author: Dr. Priya Venkatesan


medwireNews: The risk for pacemaker implantation or syncope more than trebles among people with new-onset atrial fibrillation (AF) prescribed antiarrhythmic drugs (AADs) within a year of diagnosis, suggests a study published in the Journal of the American College of Cardiology.

Jong-Il Choi (Korea University College of Medicine, Seoul) and co-investigators used Korean national health insurance data from 674,303 adults (61.1% aged ≥65 years) with new-onset AF, to compare the risk for pacemaker implantation or syncope between patients who received AADs and those who did not. AADs included flecainide, propafenone, pilsicainide, amiodarone, dronedarone, and sotalol.

After a follow-up of 1 year from either the AAD prescription date or AF diagnosis among nonusers, 1982 pacemaker implantation or syncope events occurred in 142,141 people prescribed AADs, at an incidence of 16.3 per 1000 person–years, compared with 2308 events in 532,162 people who did not take AADs, an incidence of 4.8 events per 1000 person–years.

This translated to a significant 3.5-fold increased risk for pacemaker implantation or syncope with the receipt of AADs, after adjusting for age, sex, hypertension, diabetes, dyslipidemia, chronic kidney disease, heart failure, myocardial infarction, and thyroid disease.

The researchers acknowledge that the overall incidence of the primary outcome among individuals receiving AADs was not high, but they point out that “rhythm control therapy is often lifelong, thereby elevating the risk of syncope or pacemaker implantation throughout the entire disease course.”

The “composite outcome was mainly driven by pacemaker implantation,” note the investigators, for which the adjusted hazard ratio (HR) was 5.3 with versus without AAD treatment, and the cause was primarily due to sinus node dysfunction, which was 8.2-fold higher among people in the AAD group, whereas atrioventricular node dysfunction was just 1.4-fold higher.

When analyzed separately, the risk for syncope was lower than that for pacemaker implantation, but still significantly 2.1-fold higher among people who took AADs than those who did not.

The findings were similar in propensity score matched analyses that were conducted to address significant baseline differences between the two groups, namely a higher proportion of men (59.2 vs 51.5%) and a lower proportion of people with prior stroke (6.7 vs 10.4%) in the AAD group.

Further classification of the AADS suggested that the class IC AADs studied – flecainide, propafenone, and pilsicainide – conferred a lower risk for pacemaker implantation or syncope than the other AADs, relative to no AAD treatment (HR=1.98 vs 3.44 for amiodarone and 5.08 for dronedarone or sotalol).

“When Class IC drugs were set as a reference, amiodarone and dronedarone or sotalol were associated with a significantly increased risk of pacemaker implantation or syncope,” comment the investigators. The risk was increased 1.75-fold for amiodarone, and 2.57 for dronedarone or sotalol.

Subgroup analyses revealed that all age groups experienced the bradycardia-related adverse effects associated with AADs. However, patients aged 65 years and older were significantly more susceptible, as were women and patients with dyslipidemia, note Choi et al, suggesting that “[p]rescription of AADs to individuals in these subgroups may require additional caution.”

In a linked editorial, Sanjay Dixit (Hospital of The University of Pennsylvania, Philadelphia, USA) and co-authors praise the researchers for highlighting “an important and heretofore relatively ignored aspect of AAD use in patients with AF.”

The editorialists comment that despite the study’s limitations, such as a lack of information on AAD doses and patient compliance, the findings should make clinicians “more cautious when using AADs, especially in older patients and women.”

They note that as the risk for the primary outcome was highest in the first 6 months, but persisted for more than 2 years, there is “a strong case for using catheter ablation therapy early and more often to achieve rhythm control in patients with AF,” which is supported by the most recent guidelines for diagnosis and management of AF.

medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2024 Springer Healthcare Ltd, part of the Springer Nature Group

J Am Coll Cardiol 2024; 83: 1027–1038
J Am Coll Cardiol 2024; 83: 1039–1041


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