Hellerup, Denmark—Using medications to help prevent atrial fibrillation (AF) in older patients can be a double-edged sword, according to a new study. While the drugs can be effective in helping to control heart rate or rhythm, they also can raise the risk for fainting and falls.

A study published in the Journal of the American Geriatric Society provides information on the association of rate and/or rhythm control with fall-related injuries and syncope in a real-world older AF cohort. The condition occurs in 3% to 5% of patients older than age 85 years.

The retrospective cohort study was led by researchers from Herley and Gentofte Hospital in Denmark and used Danish nationwide administrative registries from 2000 to 2015.

Participants included 100,935 patients with AF aged 65 years or older who reported prescriptions for heart rate–lowering drugs and/or anti-arrhythmic drugs (AADs). The study team compared the use of rate-lowering monotherapy with rate-lowering dual therapy, AAD monotherapy, and AAD combined with rate-lowering therapy.

Researchers were focused on how those drugs affected fall-related injuries and syncope in the cohort, 53% women with a median age of 78 years.

Results indicate that, during a median follow-up of 2.1 years (interquartile range = 1.0-5.1), 17,132 (17.0%) experienced a fall-related injury, 5,745 (5.7%) had a syncope episode, and 21,093 (20.9%) experienced either. The study team determined that, compared with rate-lowering monotherapy, AADs were associated with a higher risk of fall-related injuries and syncope. In fact, the incidence rate ratio (IRR) for the composite end point was 1.29 (95% CI, 1.17-1.43) for AAD monotherapy and 1.46 (95% CI, 1.34-1.58) for AAD combined with rate-lowering therapy.

As for specific drugs, the study reports that amiodarone significantly increased the risk of fall-related injuries and syncope (IRR = 1.40; CI,1.26-1.55). Overall, compared with more than 180 days of rate-lowering monotherapy, a higher risk of all outcomes was seen in the first 90 days of any treatment, with the greatest risk for patients in the first 14 days of treatment with AADs.

The study points out that, in addition to advancing age, several comorbidities and pharmacotherapies, such as cognitive impairment and antihypertensive treatment, are associated with the risk of falls and fall-related injuries. The authors emphasize that emerging evidence suggests that AF, the most common cardiac arrhythmia with an increasing prevalence worldwide, is also associated with greater fall risk. “In AF, both bradyarrhythmia and tachyarrhythmia can impair cardiac output, resulting in cerebral hypoperfusion and potentially leading to syncope, falls, and fall-related injuries,” according to the report. “To prevent tachycardia and AF symptoms, patients are treated with rate and/or rhythm-control therapies. Rate-lowering drugs (RLDs) and anti-arrhythmic drugs (AADs) are known to be pro-arrhythmic and can lead to bradycardia, potentially aggravating the risk of falls and syncope.”

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