Programmed ventricular stimulation for risk stratification in symptomatic athletes with nonischemic left ventricular scar and preserved ejection fraction

Aims: Non-ischaemic left ventricular (LV) scar is increasingly recognized in athletes with preserved left ventricular ejection fraction (LVEF) and may represent a substrate for malignant ventricular arrhythmias. The role of electrophysiological study (EPS) with programmed ventricular stimulation (PVS) for risk stratification in this population remains unclear. This study aimed to evaluate the prognostic value of inducibility at EPS in symptomatic athletes with non-ischaemic LV scar and preserved LVEF. Methods and results: We prospectively enrolled 72 consecutive athletes (mean age 48.9 ± 13.1 years; 66.7% male) with documented non-ischaemic LV scar, preserved LVEF (≥50%), and arrhythmic symptoms (tachycardic palpitations, syncope/presyncope, and/or exercise-related ventricular arrhythmias) undergoing EPS. Inducibility was defined as sustained ventricular arrhythmias during PVS. The primary endpoint was the occurrence of major arrhythmic events (MAE), including sudden cardiac death, sustained ventricular tachycardia/ventricular fibrillation, or appropriate implantable cardioverter-defibrillator therapy. Twenty-three athletes (31.9%) were inducible (EPS+), while 49 (68.1%) were non-inducible (EPS-). Baseline characteristics were largely comparable between groups, although QRS duration was longer in inducible athletes (104.6 ± 15.2 ms vs. 95.5 ± 14.3 ms; P = 0.019). Twenty-three inducible athletes underwent ICD implantation (18 transvenous and 5 subcutaneous devices), whereas 16 non-inducible athletes received an implantable loop recorder. During a median follow-up of 42 months, 11 major arrhythmic events occurred. Nine events occurred among inducible athletes and consisted of sustained ventricular arrhythmias (monomorphic VT, polymorphic VT, or ventricular fibrillation) successfully terminated by appropriate ICD therapy, whereas two major arrhythmic events occurred among non-inducible athletes and required successful resuscitation followed by ICD implantation. No arrhythmic deaths occurred during follow-up. Event-free survival at 50 months was 40.6% in inducible athletes and 95.9% in non-inducible athletes (log-rank P < 0.001). Conclusion: In symptomatic athletes with non-ischaemic LV scar and preserved LVEF, inducibility at EPS identifies a subgroup at higher risk of MAE, whereas non-inducibility is associated with a low event rate. EPS may represent a useful adjunctive tool for arrhythmic risk stratification in athletes, particularly in those without conventional high-risk features.