Abstract 3288: Imaging αvβ3/β5 Integrin Upregulation In Patients After Myocardial Infarction
Background- Early recognition of patients at risk of developing heart failure following acute myocardial infarction (AMI) remains elusive. The size of the scar and its progression is associated with upregulation of αvβ3/β5 integrins. We investigated whether a new 99m-Technetium labeled agent (NC100692; GE Healthcare) targeted to αvβ3/β5 integrins could be used to visualize remodeling regions after AMI. Furthermore, we examined the relationship between 99mTc-NC100692 uptake and myocardial scar formation.
Methods- Ten patients with AMI underwent routine myocardial perfusion imaging (MIBI) to evaluate the post-MI perfusion defect. Three and eight weeks thereafter, patients were injected with 99mTc-NC100692 and SPECT images of the heart were obtained after injection. Finally, delayed contrast-enhanced MRI (CMR) was performed 12 months after MI.
Results- In 7 patients, significant uptake of 99mTc-NC100692 was observed in regions of the left ventricle (LV), whereas 3 patients showed little or no uptake. In 5 out of 7 positive cases, uptake was clearly seen in the tissue beyond the infarct zone, outside the myocardial perfusion defect. One patient showed uptake of the tracer throughout the myocardium. The extent of uptake correlated well with degree of fibrosis (scarring) seen 1 year after MI by MR imaging.
Conclusions- We demonstrate that imaging of αvβ3/β5 integrin upregulation in post-MI LV remodeling using 99mTc-NC100692 is feasible in patients 3 and 8 weeks after MI. In addition, uptake of NC100692 predicted extent of fibrosis one year later. This novel imaging technology may help to better understand the biology of LV remodeling and may also predict extent of scar after MI.