Recovery of Left Ventricular Systolic Function and Clinical Outcomes in Young Adults With Myocardial Infarction.

<bold>Background: </bold>Left ventricular ejection fraction (EF) recovery is associated with better long-term outcomes after myocardial infarction (MI). However, the association between long-term outcomes and EF recovery among young MI patients has not been investigated.<bold>Objectives: </bold>This study sought to evaluate the prevalence of left ventricular systolic dysfunction among patients who experience their first MI at a young age and to compare outcomes between those who recovered their EF versus those who did not.<bold>Methods: </bold>The YOUNG-MI registry is a retrospective cohort study of patients who experienced an MI at ≤50 years of age. EF at the time of MI and within 180 days post-MI were determined from all available medical records. The primary outcomes were all-cause and cardiovascular mortality.<bold>Results: </bold>There were 1,724 patients with baseline EF data: 503 (29%) had EF <50%, whereas 1,221 (71%) had a normal baseline EF. Patients with lower EF were more likely to have experienced ST-segment elevation MI, have higher troponin values, and have more severe angiographic coronary artery disease. Among patients with abnormal baseline EF, information on follow-up EF was available for 216, of whom 90 (42%) recovered their EF to ≥50%. Patients who experienced EF recovery had less severe angiographic disease, lower alcohol use, and a lower burden of comorbidities. Over a median follow-up of 11.1 years, EF recovery was associated with an ∼8-fold reduction in all-cause mortality (adjusted hazard ratio: 0.12; p = 0.001) and a ∼10-fold reduction in cardiovascular mortality (adjusted hazard ratio: 0.10; p = 0.025).<bold>Conclusions: </bold>Nearly one-third of young patients presented with left ventricular dysfunction post-MI. Among them, EF recovery occurred in more than 40% and was independently associated with a substantial decrease in all-cause and cardiovascular mortality. [ABSTRACT FROM AUTHOR]