Abstract 2258: Infarct Mass by Contrast-Enhanced Cardiac Magnetic Resonance is a Stronger Predictor of Outcomes than Left Ventricular Ejection Fraction or End-Systolic Volume Index
Background: Left ventricular (LV) end-systolic volume index (ESVI) and ejection fraction (EF) predict long-term mortality following an acute myocardial infarction (MI). However, interpretation of LV volumes and EF within 1 week of an acute MI can be difficult due to stunning and loading conditions. We sought to correlate infarct mass, LV EF and ESVI by contrast-enhanced cardiac magnetic resonance (CMR) imaging to major cardiovascular events after MI.
Methods: CMR was performed in 112 patients within 1 week following reperfusion for an acute ST-segment elevation MI in a prospective cohort study. Univariate and multivariate Cox regression analyses were applied to identify predictors of major adverse cardiac events (MACE) defined as death, recurrent MI or symptoms of congestive heart failure (CHF).
Results: The cohort consisted of 81% men with average age 57 ± 11 years. The mean infarct mass was 26 ± 18 g (22 ± 14% of the total LV mass). The mean EF and ESVI were 41 ± 10% and 47 ± 16 ml. At a mean follow-up of 9.7 ± 6.4 months, 14 patients developed CHF, 1 recurrent MI and 1 died suddenly. Infarct mass (1.041 [1.018 – 1.065 95% CI], p = 0.001), EF (0.930 [0.886 – 0.976], p = 0.003) and ESVI (1.032 [1.007 – 1.057], p = 0.011) were the only independent significant predictors of MACE. However, infarct mass was the strongest predictor of MACE by multivariate analysis.
Conclusions: Infarct mass, EF and ESVI performed within 1 week after an acute MI can predict the development of future CHF. Infarct mass measured by contrast-enhanced CMR, which is independent of stunning and LV loading, was a stronger predictor of CHF than either of the other two measurements.