Programmed ventricular stimulation for risk stratification in patients with myocardial scarring and mildly reduced or preserved ejection fraction.

Abstract

Background: Implantable cardioverter defibrillators (ICD) are recommended in patients with left ventricular ejection fraction (LVEF) below or equal to 35%. However, no recommendation exists to guide the use of prophylactic ICD in patients with less altered LVEF and myocardial scarring, even though they represent the majority of sudden cardiac deaths (SCD).

Objective: To evaluate the prognostic value of programmed ventricular stimulation (PVS) in patients with mildly reduced or preserved LVEF.

Methods: Patients who underwent PVS with myocardial scarring and LVEF ≥ 40% were included. The primary endpoint was the occurrence of a major arrhythmic event (MAE), namely SCD, ventricular tachycardia (VT)/fibrillation, and appropriate ICD therapy.

Results: 168 patients were included (mean age 62 ± 13 years, LVEF 54 ± 9 %). Indication for PVS was mostly non-sustained VT and/or syncope (83%). Post-myocardial infarction patients represented about half of the cases (52%). Inducibility during PVS was observed in 21 patients (13%). Over a mean follow-up of 46 ± 38 months, a MAE occurred in 9 patients with positive PVS (43%), versus 4 patients (2.7%) with negative PVS. Inducibility during PVS provided high rule-out performance with a 97% negative predictive value for the prediction of MAE and a fair rule-in performance with a 43% positive predictive value (sensitivity 69%, specificity 92%).

Conclusion: PVS is a useful tool to discriminate patients with myocardial scar and LVEF ≥ 40% at increased arrhythmic risk. Effective utilization of ICD may be anticipated in case of positive PVS, while non-inducible patients are at lower MAE risk.