Are there any clinical and electrocardiographic predictors of heart rate reduction in relapsing- remitting multiple sclerosis patients treated with fingolimod?

•Fingolimod has proven to be an effective oral treatment strategy for RRMS patients.•Lower BMI and optic nerve involvement are related with greater HR reduction.•Higher baseline HR and longer TpTe-interval are related with greater HR reduction.•Subjects with these features may deserve more attention during monitorization. Fingolimod, a sphingosine-1-phosphate receptor agonist, is used for treatment of relapsing-remitting multiple sclerosis (RRMS). S1P receptors that fingolimod acts upon have also been shown to be expressed on atrial myocytes. This expression pattern has been linked with the drug's cardiovascular effects, such as bradycardia. We aimed to evaluate the clinical and electrocardiographic predictors of heart rate (HR) reduction in patients receiving first-dose fingolimod. We retrospectively analyzed subjects diagnosed with RRMS who were allocated to fingolimod treatment. HR, systolic and diastolic blood pressure values and electrocardiography during the first dose of fingolimod were accessed. A total of 114 RRMS patients (65.8% female, 33.58 ± 8.63 years) were included. After the initial dose of fingolimod, the heart rate decreased significantly at each hour (each p