Delayed Recovery of Myocardial Blood Flow After Intracoronary Stem Cell Administration Mariann Gyöngyösi & Rayyan Hemetsberger & Susanne Wolbank & Valentin Pichler & Christoph Kaun & Aniko Posa & Zsolt Petrasi & Örs Petnehazy & Renate Hofer-Warbinek & Rainer de Martin & Florian Gruber & Imre Benedek & Teodora Benedek & Istvan Kovacs & Istvan Benedek Jr. & Christian A. Plass & Silvia Charwat & Gerald Maurer Published online: 10 December 2010 # Springer Science+Business Media, LLC 2010 Abstract The aim of the present study was to investigate the changes in absolute myocardial blood flow (AMF) after intracoronary injections of mesenchymal SC (MSC) and compared to controls in closed-chest reperfused acute myocardial infarction (AMI) in pigs. Male MSCs, transiently transfected with Luciferase (Luc-MSC) were delivered 9:7 Æ 1:2 Â 10 6 ð Þ intracoronary in the open infarct-related artery one-week post-AMI in female pigs (group MSC), while saline was injected with the same injection rate in controls (group C). The AMF was measured immediately after, and 3, 12 and 24 h post-intracoronary Luc-MSC or saline injections. In vitro bioluminescence images and quantitative real-time TaqMan PCR measurements were performed to quantify the sex-mismatched MSCs. No difference between the groups was observed regarding the weight, heart rate, blood pressure and global ejection fraction 1-week post-AMI. The baseline AMF were similar in the groups (61.3±15. vs 61.1±12.0 ml/min). AMF was de- creased significantly immediately after intracoronary MSC delivery (42.0±12.4 vs 57.7±15.7 ml/min p =0.013), and remained low at 3 h (40.9±13.4 vs 55.8±4.9 ml/min, p = 0.004), 12 h (43.0±3.7 vs 57.8±5.4 ml/min, p =0.001) with incomplete recovery at 24 h (47.2±5.5 vs 62.1±14.1 ml/min, p =0.038) as compared to controls, respectively. In vitro bioluminescence displayed transfected Luc-MSCs along the proximal and mid part of the LAD, with limited number (295± 101 sry copied/million cardiac cells) of Y-chromosome-MSCs in the infarcted area. Intracoronary injection of SCs results in immediate decrease of AMF, with delayed recovery. The delivery of the SC into the injured myocardium might be hindered by the altered coronary pressure and flow conditions. Keywords Myocardial infarction . Blood flow . Catheterization . Imaging . Stem cells Introduction Potential complications of intracoronary stem cell (SC) delivery include periprocedural infarction secondary to temporary no-flow, reduced coronary blood flow, hypervis- cosity from the cell preparation or microvascular dysfunction M. Gyöngyösi (*) : R. Hemetsberger : C. Kaun : A. Posa : C. A. Plass : S. Charwat : G. Maurer Department of Cardiology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria e-mail: mariann.gyongyosi@meduniwien.ac.at S. Wolbank : V. Pichler Ludwig Boltzmann Institute for Clinical and Experimental Traumatology /AUVA Research Center Austrian Cluster for Tissue Regeneration, Vienna, Austria Z. Petrasi : Ö. Petnehazy Institute of Diagnostic Imaging and Radiation Oncology, University of Kaposvar, Kaposvar, Hungary R. Hofer-Warbinek : R. de Martin Department of Biomolecular Medicine and Pharmacology, Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria F. Gruber Department of Dermatology, Medical University of Vienna, Vienna, Austria I. Benedek : T. Benedek : I. Kovacs : I. Benedek Jr. Department of Cardiology, University of Targu Mures, Targu Mures, Romania Stem Cell Rev and Rep (2011) 7:616–623 DOI 10.1007/s12015-010-9213-7