Electrocardiographic Indices Predicting Disability in Relapsing- Remitting Multiple Sclerosis: A Cross-Sectional Study

Background: Multiple sclerosis (MS) is increasingly recognized as a systemic disease with cardiovascular involvement. The frontal QRS-T angle (fQRS-T) reflects repolarization heterogeneity and is linked to arrhythmic risk in various conditions; however, its role in MS remains unclear. This study aimed to compare fQRS-T and related electrocardiographic indices between patients with relapsing–remitting MS (RRMS) and healthy controls, and to examine their association with disability severity. Methods: In this retrospective, cross-sectional study, 101 RRMS patients and 51 age- and sex-matched healthy individuals were evaluated. RRMS patients were stratified by disability severity using the Expanded Disability Status Scale (EDSS <6 vs. ≥6). Resting 12-lead ECGs were assessed for QT, Tp-e, Tp-e/QTc, fQRS-T angle, and indices of cardiac electrophysiological balance (iCEB, iCEBc) by two blinded cardiologists. Statistical analyses included univariate comparisons, logistic regression, and ROC analysis. Results: RRMS patients had significantly greater fQRS-T angles and iCEBc values compared to controls (p<0.05). Within the RRMS cohort, those with EDSS ≥6 exhibited higher fQRS-T and iCEB values (p<0.01). In multivariable analysis, fQRS-T angle (OR 1.036; p=0.010) and iCEB (OR 3.544; p=0.001) independently predicted severe disability. The fQRS-T angle demonstrated moderate diagnostic performance (AUC: 0.718; cut-off 32°). Conclusion: These findings indicate that RRMS patients exhibit subclinical ECG abnormalities that correlate with disability severity, and incorporating ECG-derived metrics into clinical monitoring may aid in risk stratification of RRMS patients with high disability burden. Trial registration: Not applicable; this was a retrospective cross-sectional observational study.