MULTIPLE SCLEROSIS AND RELATED DISORDERS, cilt.76, ss.1-5, 2023 (SCI-Expanded)
Background: Fingolimod is indicated for the treatment of relapsing–remitting multiple sclerosis (RRMS) and also
targets cardiovascular system due to receptors on cardiomyocytes. Results of previous studies are controversial
for the effect of fingolimod in terms of ventricular arrhythmias. Index of cardio-electrophysiological balance
(iCEB) is a risk marker for predicting malignant ventricular arrhythmia. There is no evidence on the effect of
fingolimod on iCEB in patients with relapsing–remitting multiple sclerosis (RRMS). The aim of this study was to
evaluate iCEB in patients with RRMS treated with fingolimod .
Methods: A total of 86 patients with RRMS treated with fingolimod were included in the study. All patients
underwent a standard 12-lead surface electrocardiogram at initiation of treatment and 6 h after treatment. Heart
rate, RR interval, QRS duration, QT, QTc (heart rate corrected QT), T wave peak-to-end (Tp-e) interval, Tp-e/QT,
Tp-e/QTc, iCEB (QT/QRS) and iCEBc (QTc/QRS) ratios were calculated from the electrocardiogram. QT
correction for heart rate was performed using both the Bazett and Fridericia formulas. Pre-treatment and posttreatment values were compared.
Results: Heart rate was significantly lower after fingolimod treatment (p< 0.001). While the post-treatment values
of RR and QT intervals were significantly longer (p< 0.001) and post-treatment iCEB was higher (median [Q1-
Q3], 4.23 [3.95–4.50] vs 4.53 [4.18–5.14]; p< 0.001), it was found that there was no statistically significant
change in iCEB and other study parameters derived using QT after correcting for heart rate using both of two
formulas.
Conclusions: In this study, it was found that fingolimod did not statistically significantly change any of the heart
rate-corrected ventricular repolarization parameters, including iCEBc, and it is safe in terms of ventricular
arrhythmia.