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

Introduction: 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). This method assessed the performance of a two-step, programmed ventricular stimulation (PVS)-inclusive approach in identifying high-risk post-MI patients with LVEF ≥40%. This report presents findings from the 8-year follow-up. Methods: The primary endpoint was the occurrence of a major arrhythmic event, defined as sustained ventricular tachycardia/fibrillation, appropriate implantable cardioverter-defibrillator (ICD) activation, or sudden cardiac death (SCD). We included a total of 575 consecutive patients (mean age 57 years, LVEF 50.8%). Of them, 204 (35.5%) had at least one positive non-invasive risk factor. Forty-one of 152 patients undergoing PVS were inducible; 37 (90.2%) of them received an ICD. Results: During a mean follow-up of 106 ± 14.5 months, no SCDs were observed, while 12 ICDs (the major arrhythmic event prevalence in patients with ICD implantation reaching 29.3%) were appropriately activated. The updated performance metrics of the proposed approach were as follows: sensitivity 100% (95% CI: 73.5%-100%), specificity 94.8% (95% CI: 92.5-96.5%), positive predictive value 29.3% (95% CI: 17.2-45.0%), and negative predictive value 100% (95% CI: 99.3%-100%). Notably, events occurred only in patients with an LVEF 40%-50% and a history of ST-Elevation Myocardial Infarction. Conclusion: The PRESERVE EF study demonstrates that a simple, two-step, non-invasive risk factor-guided approach, followed by programmed ventricular stimulation, can effectively identify a subgroup of post-MI patients with preserved or mid-range LVEF ≥40 who are at high risk for major arrhythmic events. Clinical Trial Registration: Clinicaltrials.gov, identifier NCT02124018.