Abstract 2548: Cardiac Computed Tomography for Prediction of Myocardial Viability after Reperfused Acute Myocardial Infarction
Background: Given its ability to detect hypoenhanced myocardium in patients after acute myocardial infarction, cardiac computed tomography (CCT) may be a modality that can predict myocardial viability after acute myocardial necrosis. We investigated the feasibility of 64-slice CCT to predict left ventricular recovery after revascularized first acute ST-segment elevation myocardial infarction (STEMI).
Methods and Results: Seventeen patients (mean age 60 ± 10 years, 14 males) presenting with first acute STEMI treated with primary percutaneous coronary intervention (average door to balloon time 81±34 minutes) were studied. Each patient underwent 64-slice CCT and cardiac magnetic resonance (CMR) at baseline (mean 2.9 ± 1.0 days after STEMI) and a follow-up CMR at 6 months (6 ± 1.5 months). 64-slice CCT during the first pass of contrast was performed to image infarcted myocardium as demonstrated by a perfusion defect (PD), visualized as a region with decreased myocardial attenuation. The degree of transmurality of PD on CCT was correlated to change in regional left ventricular function (LVF) as assessed by serial CMR examinations. An improvement by one category or more in the regional wall motion score at follow-up was considered evidence of left ventricular recovery. A total of 680 segments were evaluated, of which 204 (30%) segments demonstrated a PD on CCT. The transmurality of PD on CCT predicted LVR at follow-up. Only 2/23 (9%) of the segments with >75% transmurality of PD at baseline demonstrated improved regional LVF at follow-up, whereas 21/23 (91%) of the segments remained the same or demonstrated worsening regional LVF. On the other hand, the majority 42/65 (65%) of segments with <25% transmurality of PD at baseline demonstrated improved regional LVF at follow-up, while only 1/65 (1.5%) of these segments demonstrated worsening regional LVF. The odds ratio for any improvement in regional LVF with increasing PD category was 0.54 (95% CI: 0.0.39 – 0.73, p<0.0001).
Conclusions: CCT is a technique that may provide information regarding myocardial viability after acute STEMI. Our results suggest that the degree of PD transmurality on baseline CCT after revascularized acute myocardial infarction may predict regional left ventricular recovery.