MR assessment of myocardial perfusion, viability, and function after intramyocardial transfer of VM202, a new plasmid human hepatocyte growth factor in ischemic swine myocardium.
OBJECTIVE
VM202, a newly constructed plasmid human hepatocyte growth factor, was transferred intramyocardially after infarction for the purpose of evaluating this strategy as a therapeutic approach for protection from left ventricular (LV) remodeling.


METHODS
The institutional animal care and use committee approved this study. Pigs underwent coronary artery occlusion and reperfusion and served as either control (n = 8) or VM202-treated (n = 8) animals. VM202 was transferred intramyocardially into four infarcted and four periinfarcted sites. Cardiac magnetic resonance (MR) imaging (cine, perfusion, delayed enhancement) was performed in acute (3 days) and chronic (50 days +/- 3 [standard error of the mean]) infarction. Histopathologic findings were used to characterize and quantify neovascularization. The t test was utilized to compare treated and control groups and to assess changes over time.


RESULTS
In acute infarction, MR imaging estimates of function, perfusion, and viability showed no difference between the groups. In chronic infarction, however, VM202 increased maximum signal intensity and upslope at first-pass perfusion imaging and reduced infarct size at perfusion and delayed-enhancement imaging. These changes were associated with a decrease in end-diastolic (2.15 mL/kg +/- 0.12 to 1.73 mL/kg +/- 0.10, P < .01) and end-systolic (1.33 mL/kg +/- 0.07 to 0.92 mL/kg +/- 0.08, P < .001) volumes and an increase in ejection fraction (38.2% +/- 1.3 to 47.0% +/- 1.8, P < .001). In contrast, LV function deteriorated further in control animals. Compared with control animals, VM202-treated animals revealed peninsulas and/or islands of viable myocardium in infarcted and periinfarcted regions and greater number of capillaries (218 per square millimeter +/- 19 vs 119 per square millimeter +/- 17, P < .05) and arterioles (21 per square millimeter +/- 4 vs 3 per square millimeter +/- 1, P < .001).


CONCLUSIONS
Intramyocardial transfer of VM202 improved myocardial perfusion, viability, and LV function.
Saeed
Maythem
M
Department of Radiology and Biomedical Imaging, University of California San Francisco, 513 Parnassus Ave, HSW 207B, San Francisco, CA 94134-0628, USA. Maythem.Saeed@radiology.UCSF.edu
Martin
Alastair
A
Ursell
Phillip
P
Do
Loi
L
Bucknor
Matt
M
Higgins
Charles B
CB
Saloner
David
D
D000818:Animals; D003326:Coronary Circulation / Q000502:physiology*; D017228:Hepatocyte Growth Factor / Q000008:administration & dosage / Q000627:therapeutic use*; D019028:Magnetic Resonance Imaging, Cine; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000188:drug therapy* / Q000503:physiopathology; D013552:Swine; D014022:Tissue Survival; D020257:Ventricular Remodeling / Q000187:drug effects
D017228:Hepatocyte Growth Factor