Cell Transplant. 2009 Aug 5; Ghanem A, Ziomka A, Krausgrill B, Schenk K, Troatz C, Michalszki-Jamka T, Nickenig G, Tiemann K, Müller-Ehmsen JIntramyocardial transplantation of bone marrow derived stem cells is a potential therapeutic option after myocardial infarction (MI). Intramyocardial administration is invasive but allows efficient and targeted stem cell delivery. Aims of this study were validation of minimal-invasive, echo-guided closed-chest cell transplantation (CTx) of mononuclear (MNC) or mesenchymal stem cells (MSC) and quantification of systolic left-ventricular function and assessment of contractile reserve with high-resolution reconstructive 3D-echocardiography (r3D-echo) three weeks after CTx.Female Fischer344 rats received syngeneic male MNC, MSC or medium after myocardial ischemia and reperfusion via echo-guided percutaneous injection (open-chest for control). Left-ventricular systolic function was measured and dysfunctional myocardium was quantified with r3D-echo. For investigation of contractile reserve and myocardial viability r3D-echo was additionally conducted during low-dose dobutamine three weeks after CTx. Cell persistence after echo-guided CTx was quantified via real-time PCR, scar size was measured histologically.Echo-guided percutaneous CTx was feasible in all animals (n=30) without periprocedural complications. 1.4+/-1.1% of transplanted MNC and 1.9+/-1.2% of MSC were detected after three weeks. These numbers were comparable to those after open-chest intramyocardial injection of MNC (0.8+/-1.1%; n=8, p=0.3). In r3D-echo no functional benefit was associated with CTx after MI and reperfusion. All groups (MNC, MSC and controls) revealed a significant decrease of dysfunctional myocardium and similar contractile reserve during inotropic stimulation.In conclusion, percutaneous echo-guided closed-chest CTx promises to be an effective and safe approach for CTx in small animal research. However, intramyocardial CTx of MNC or MSC had no influence on systolic function and contractile reserve after reperfused MI.