Abstract 4190: Prognostic Value of Myocardial Infarction and Left Ventricular Ejection Fraction in Elderly Subjects: Insights from the ICELAND-MI Substudy of AGES-Reykjavik
The aim of this study was to determine the prognostic value of myocardial infarction (MI) and left ventricular ejection fraction (LVEF) in an older-aged, ambulatory cohort with baseline MI defined by magnetic resonance imaging (MRI) with gadolinium. The cohort was randomly selected from the Age, Gene/Environment Susceptibility-Reykjavik Study, an epidemiologic study of Icelandic men and women 68 –93 years. Participants underwent cardiac MRI to measure LVEF and to define MI with gadolinium. New cardiac events were defined as the composite of cardiac death, MI, and hospitalization for heart failure. Of the 667 subjects (average age 76 with 309 men), 142 (21.3%) had LVEF (<55%) and 136 (20.4%) had an MI identified on MRI (MRI-MI). The prevalence of MRI-MI increased with worsening LVEF: 13.7%, 41.6% and 83.3% in the groups with LVEF ≥ 55%, 36 –54% and ≤ 35%, respectively, but 57.6% of subjects with MRI-MI had normal LVEF. Over 2.4 years of follow-up, 76 (11.4%) individuals suffered an event. MRI-MI strongly increased the risk of new events for subjects with LVEF >55% (event rate 22.2% vs 8.6%) and LVEF 36 –54% (event rate18.5% vs 6.6%). MRI-MI was the strongest predictor of cardiac events and LVEF was not independently significant in models that included MRI-MI. The presence of MRI-MI was associated with substantially increased risk of cardiac events in subjects with normal LVEF and mildly to moderately abnormal LVEF. Diagnosis of MRI-MI was more powerful than LV function assessment when predicting cardiac events in the elderly.