Abstract 2126: Risk Stratification After Reperfused Acute Myocardial Infarction Using Contrast-enhanced Cardiovascular Magnetic Resonance: Comparison Of First-pass And Delayed Enhancement Imaging
The established parameter for risk stratification after reperfused acute myocardial infarction (MI) is left ventricular (LV) ejection fraction (EF). With the use of contrast-enhanced cardiovascular magnetic resonance (CMR) further parameters for characterization of MI can be determined. We investigated which of the CMR perfusion techniques, first-pass perfusion (FP) or delayed enhancement (DE) would show the best relation to the occurence of major adverse cardiac events (MACE).
Methods: 148 patients (pts) with left ventricular (LV) dysfunction (EF 3±8%) were examined on a 1.5T scanner within 3±2 (2– 6) days of an reperfused acute MI. Cine, FP perfusion and DE CMR was acquired. LV EF, infarct size (IS) (from DE imaging) and the extent of microvascular obstruction (MO) (from FP imaging) were quantified. Serial clinical follow-up was obtained in all patients (mean follow-up 4.3±1.8 years) regarding occurrence of MACE. Patient-related and CMR data were analyzed by Cox proportional hazard regression.
Results: Among the 148 patients, there were 34 cardiac deaths and reinfarctions in the follow-up period, additionally there were 32 patients with further myocardial revascularization or hospitalization due to unstable angina or congestive heart failure. Patients with events at follow-up showed significantly lower EF (32±10% vs. 46±10%, p < 0.001), larger extent of IS (21±11% vs. 13±13%, p = 0.008), and larger extent of MO (10±9% vs. 2±8%, p < 0.001) than patients without events. By univariate analysis, EF, extent of MO, and, infarct size by CMR were related to occurence of MACE (Table⇓). By multivariable analysis, extent of MO remained the strongest predictor after adjustement for LV EF.
Conclusions: In patients after reperfused acute MI, contrast-enhanced CMR can be used to predict major adverse cardiac events. Next to the established parameter for risk stratification - ejection fraction -, the extent of MO determined from FP imaging prooved highly predictive.