PT - JOURNAL ARTICLE AU - Nguyen Tran AU - Philippe R. Franken AU - Fatiha Maskali AU - Joseph Nloga AU - Pablo Maureira AU - Sylvain Poussier AU - Frederique Groubatch AU - Chris Vanhove AU - Jean-Pierre Villemot AU - Pierre-Yves Marie TI - Intramyocardial Implantation of Bone Marrow–Derived Stem Cells Enhances Perfusion in Chronic Myocardial Infarction: Dependency on Initial Perfusion Depth and Follow-up Assessed by Gated Pinhole SPECT DP - 2007 Mar 01 TA - Journal of Nuclear Medicine PG - 405--412 VI - 48 IP - 3 4099 - http://jnm.snmjournals.org/content/48/3/405.short 4100 - http://jnm.snmjournals.org/content/48/3/405.full SO - J Nucl Med2007 Mar 01; 48 AB - Cell therapy–induced changes in the perfusion of areas of myocardial infarction (MI) remain unclear. This study investigated whether an original pinhole SPECT technique could be applied to a rat MI model to analyze local improvement in myocardial perfusion relating to engraftment sites of bone marrow–derived stem cells (BMSCs). Methods: Four-month-old MI rats were either untreated (n = 8) or treated (n = 10) by intramyocardial injection of 111In-labeled BMSCs. Early distribution of 111In-BMSCs within the MI target was evidenced by dual 111In/99mTc pinhole SPECT 48 h later. Myocardial perfusion was serially monitored by 99mTc-sestamibi pinhole gated SPECT up to 3 mo after transplantation. Results: Forty-eight hours after transplantation, 111In-BMSCs were observed in all treated rats and in 18 of their 32 underperfused MI segments (<70% sestamibi uptake before transplantation). During the subsequent 3-mo follow-up, the perfusion of MI segments worsened in untreated rats (absolute change in sestamibi uptake, −3% ± 3%; P < 0.05) but improved in treated rats (+4% ± 7%; P < 0.05). This perfusion improvement was unrelated to the initial detection of 111In-BMSCs (+2% ± 6% in segments with 111In-BMSCs vs. +5% ± 7% in those without; not statistically significant) but was strongly associated with less severe perfusion defects before transplantation (+6% ± 6% in segments with 60%–70% sestamibi uptake [n = 19] vs. −1% ± 6% in those with <60% uptake [n = 13]; P = 0.003). Conclusion: When BMSCs are injected within chronic MI, perfusion enhancement predominates in the MI areas showing a high enough residual perfusion before treatment but not in those of the initial cell engraftment, giving evidence of dependency on the perfusion and metabolic environment at implantation sites.