Early molecular imaging of interstitial changes in patients after myocardial infarction: comparison with delayed contrast-enhanced magnetic resonance imaging.
BACKGROUND
The clinical feasibility of noninvasive imaging of interstitial alterations after myocardial infarction (MI) was assessed using a technetium-99m-labeled RGD imaging peptide (RIP). In experimental studies, RIP has been shown to target integrins associated with collagen-producing myofibroblasts (MFB).


RESULTS
Ten patients underwent myocardial perfusion imaging (MPI) within the first week after MI. At 3 and 8 weeks after MI, RIP was administered intravenously and SPECT images acquired for interstitial imaging. RIP imaging was compared to initial MPI and to the extent of scar formation defined by late gadolinium-enhanced (LGE) cardiac magnetic resonance (CMR) imaging 1 year after MI. RIP uptake was observed in 7 of the 10 patients at both 3 and 8 weeks. Although, RIP uptake corresponded to areas of perfusion defects, it usually extended beyond the infarct zone to a variable extent; 2 of 7 patients showed tracer uptake throughout myocardium. In all positive cases, RIP uptake was similar to the extent of scar observed at 1 year by LGE-CMR imaging.


CONCLUSIONS
This study demonstrates that RGD-based imaging early after MI may predict the eventual extent of scar formation, which often exceeds initial MPI deficit but colocalizes with LGE in CMR imaging performed subsequently.
Verjans
Johan
J
Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands.
Wolters
Sander
S
Laufer
Ward
W
Schellings
Mark
M
Lax
Michelle
M
Lovhaug
Dagfinn
D
Boersma
Hendrikus
H
Kemerink
Gerrit
G
Schalla
Simon
S
Gordon
Paul
P
Teule
Jaap
J
Narula
Jagat
J
Hofstra
Leonard
L
D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000494:pharmacology*; D017023:Coronary Angiography / Q000379:methods; D005260:Female; D005682:Gadolinium / Q000494:pharmacology; D006333:Heart Failure; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology; D010477:Perfusion; D011446:Prospective Studies; D017256:Technetium Tc 99m Sestamibi; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
D003287:Contrast Media; D017256:Technetium Tc 99m Sestamibi; D005682:Gadolinium