Heart rate variability predicts the magnitude of heart rate decrease after fingolimod initiation.

Area of Science:

• Cardiology
• Neurology
• Pharmacology

Background:

• Fingolimod is a disease-modifying therapy for relapsing-remitting multiple sclerosis (RRMS).
• Initiation of fingolimod can cause a significant decrease in heart rate (HR), necessitating clinical monitoring.
• Predicting this HR decrease is crucial for patient safety during fingolimod treatment.

Purpose of the Study:

• To prospectively investigate the predictive capability of cardiac autonomic regulation for the magnitude of HR decrease post-fingolimod initiation.
• To identify specific HRV parameters that correlate with fingolimod-induced bradycardia.

Main Methods:

• Twenty-five RRMS patients underwent 24-h ambulatory ECG monitoring before fingolimod initiation (baseline) and on the day of first dose.
• Heart rate variability (HRV) parameters, including pNN50, were assessed at baseline to evaluate cardiac autonomic regulation.
• Maximal HR decrease (ΔHR) was measured in beats/min and percentage after the first fingolimod dose.

Main Results:

• The average maximal HR decrease was -20±11 beats/min (-23±12%).
• Baseline pNN50 showed a significant negative correlation with the percentage of HR decrease (r=-0.657, p<0.001).
• A baseline pNN50 ≥10% predicted a ≥20% HR decrease with 76% accuracy (83% positive, 69% negative predictive values).

Conclusions:

• Cardiac autonomic regulation, specifically a baseline pNN50 >10%, can effectively predict the magnitude of heart rate decrease following the first dose of fingolimod.
• This predictive marker can inform clinical vigilance and management strategies for patients initiating fingolimod therapy.