Arrhythmic risk stratification in post-myocardial infarction patients with preserved ejection fraction: Long-term outcomes from the PRESERVE EF study

Background The PRESERVE EF study proposed a two-step algorithm for risk stratification in post-myocardial infarction (MI) patients with mid-range and preserved left ventricular ejection fraction (LVEF). Purpose The PRESERVE EF study assessed the performance of a multifactorial, two-step, programmed ventricular stimulation (PVS)-inclusive approach in identifying the high-risk post-MI patients with LVEF ≥40% who are at increased arrhythmic risk and would benefit from an implantable cardioverter-defibrillator (ICD). This report presents the 8-year follow-up findings of the trial. Methods The primary endpoint was the occurrence of a major arrhythmic event (MAE), namely sustained ventricular tachycardia/fibrillation, appropriate ICD activation or sudden cardiac death (SCD). We screened and included 575 consecutive patients (mean age 57 years, LVEF 50.8%). Of them, 204 (35.5%) had at least one positive NIRF. Forty-one of 152 patients undergoing PVS were inducible. Thirty seven (90.2%) of them received an ICD. Results Over a mean follow-up of 106 ± 14.5 months, no SCDs were observed, while 12 ICDs (the major arrhythmic events prevalence in patients with ICD implantation reaching 29.3%) were appropriately activated. The updated (8.8-year follow-up) performance metrics of the proposed approach (included both steps with NIRFs and PVS) were as follows: Sensitivity= 100%, specificity= 94.8%, positive predictive value= 29.3%, and negative predictive value= 100%. Notably, events occurred only in patients with an LVEF 40-50% and STEMI. Conclusions Until a randomized trial provides a survival benefit in post-myocardial infraction patients with preserved LVEF, the PRESERVE EF study remains the only evidence based risk assessment approach, despite its observational structure.