Abstracts

Rationale: Recently, the FDA issued a Drug Safety Communication for the antiepileptic drug lamotrigine warning of the possibility of QRS prolongation and proarrhythmia. In this study, we characterized the prevalence and incidence of arrythmias in 3 patient groups, epilepsy patients taking ASMs (anti-seizure medications), epilepsy patients not taking ASMs, and non-epileptic patients. This was also characterized for ASMs given as monotherapy.

Methods: Data from Truveta, an EHR-based platform that consists of longitudinal records from patients from 31+ US health systems as of December 2023, were analyzed. We examined the prevalence and incidence of ventricular arrhythmias and all types of cardiac arrhythmias in 2023. Patient groups included (1) treated epilepsy patients who received any of the 27 ASMs, (2) epilepsy patients who did not receive ASMs, and (3) non-epilepsy patients who had a record of any other condition. Annual prevalence of arrhythmias was calculated as the number of patients with at least one record of an arrhythmia out of the total number of patients in that year for each of the 3 patient groups. Incidence was calculated as the number of patients with a new record of arrhythmia, out of the total number of patients in that year who did not previously have a record of arrhythmia. We also examined the prevalence and incidence of arrhythmias in each monotherapy ASM group. Of the 27 ASMs, 16 had enough relevant data to be included in the prevalence and incidence of arrhythmias in monotherapy groups.

Results: Of the three patient groups (total N=32,063,470), treated epilepsy patients had the highest prevalence and incidence of ventricular and all-type arrythmias (Figure 1). The prevalence of all-type cardiac arrhythmias was 23.2% among treated epilepsy patients (n=264,935), 17.6% among untreated epilepsy patients (n=96,028), and 9.8% among non-epilepsy patients (n=31,702,507). The prevalence of ventricular arrhythmias was 2.9% among treated epilepsy patients, 1.8% among untreated epilepsy patients, and 1.3% among non-epilepsy patients, respectively. The incidence of new arrhythmias was 1.8% among treated epilepsy patients, 1.2% among untreated epilepsy patients, and 0.7% among non-epilepsy patients, respectively. There was variability in the prevalence and incidence of arrhythmias when various ASMs were taken as monotherapy (Figure 2). The magnitude of the incidence or prevalence was independent of the patient group size (see upper panels in Figure 2).

Conclusions: This study confirms that patients with epilepsy have a higher burden of arrhythmias when compared to non-epileptic patients. It also shows that epileptic patients taking ASMs have a higher burden of arrhythmias than epileptic patients not taking ASMs. Overall, the incidence of new arrhythmias in epileptic patients was low (less than 2%), independent of taking ASMs. For ASMs taken as monotherapy, there was a wide variability of arrhythmia burden. This suggests that some ASMs may be more likely to cause arrythmias than others.

Funding: Funded by SK Life Science, Inc.