Abstract 8626: Multi Detector CT Accurately Defines Infarct Size, but not Microvascular Obstruction Post Myocardial Infarction, and Sodium Nitrite Increases Microvascular Obstruction Region Blood Flow Without Affecting CT Hypoenchancement Area
(a) Purpose To determine what areas of hyperenchancement and hypoenhancement on multi-detector CT (MDCT) represent in terms of infarct size and myocardial regional blood flow (RBF), and the effect of nitrite on RBF and MDCT contrast patterns.
(b) Materials and Methods MDCT contrast-defined I, MVO, and non-infarct remote (R) areas in vivo were compared to matched areas defined ex vivo by triphenyltetrazolium chloride (TTC) staining (infarct area) and Thioflavin S exclusion (TSE) (area of MVO), and their RBF by fluorescent microspheres and flow cytometry, in 16 female Landrace pigs who underwent mid-LAD myocardial infarction (MI) (90 minutes ischemia, 120 minutes reperfusion), and treated with saline (n=8) or nitrite (n=8). All analyses were performed by at least two blinded observers.
(c) Results There was a correlation between infarct area on CT and that defined by TTC (r2=0.75). There was a poor correlation between MVO on CT and MVO by TSE (r2=0.46). TTC and TSE identified distinct differences in flow within R (1.2 ± 0.19 ml/min/g), I (0.62 ± 0.11 ml/min/g), and MVO (0.3 ± 0.04 ml/min/g) areas, respectively. Despite increased RBF in remote (+45%) and MVO (+80 %) regions in nitrite group compared to saline, there was no corresponding change in MDCT contrast patterns. Two animals died in each group.
(d) Conclusion MDCT is a reliable predictor of infarct size but not microvascular obstruction at 24 hours post infarction. Sodium nitrite increased RBF to MVO regions, but this was not detected by MDCT.
- Cardiac CT
- Coronary microcirculation
- Ischemia reperfusion
- Myocardial perfusion
- Myocardial infarction, STEMI
- © 2011 by American Heart Association, Inc.