Functional assessment of myoblast transplantation for cardiac repair with magnetic resonance imaging.
BACKGROUND
Contraction of transplanted myoblasts and their effects on function and remodeling after myocardial infarction remain controversial.


OBJECTIVE
We used magnetic resonance imaging (MRI) to study wall thickening and left ventricular (LV) function and geometry after myoblast transplantation.


RESULTS
Three weeks after cryo-infarction rabbits were randomized to receive an injection of approximately 2 x 10(8) myoblasts (n=8) or medium (n=9) into the scar. Cine MRI and contrast enhanced (ce) MRI images were acquired before injection (baseline) and 4 weeks later (endpoint). Regional wall thickening was measured at the site of transmural hyperenhancement. In the control group, regional wall thickening decreased to -15.3+/-8.6% at baseline, which further decreased to -18.3+/-5.7% at endpoint. Further, end-diastolic volume increased from 3.96+/-0.27 to 5.00+/-0.46 ml and end-systolic volume from 2.23+/-0.19 to 2.96+/-0.30 ml (both P<0.05 vs. baseline), which was accompanied by increased LV wall volumes (P<0.05 vs. baseline). In contrast, myoblast transplantation increased regional wall thickening from -11.9+/-15.9% at baseline to 26.9+/-17.0% (P<0.05 vs. control), which resulted in significantly improved two-dimensional ejection fractions at the infarct level and prevented the increase in end-diastolic and end-systolic volumes and wall volume.


CONCLUSIONS
Intracardiac myoblast transplantation after myocardial infarction improves regional wall thickening and prevents progressive left ventricular remodeling.
van den Bos
Ewout J
EJ
Department of Cardiology, Duke University Medical Center, Durham, NC 27710, USA.
Thompson
Richard B
RB
Wagner
Anja
A
Mahrholdt
Heiko
H
Morimoto
Yoshihisa
Y
Thomson
Louise E J
LE
Wang
Lynn H
LH
Duncker
Dirk J
DJ
Judd
Robert M
RM
Taylor
Doris A
DA
D000818:Animals; D002478:Cells, Cultured; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D032446:Myoblasts / Q000637:transplantation*; D011817:Rabbits; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling