Silviu Itescu The Legend, page-277

I was interested to read this study by Mesoblast which partly covers your question about MSC delivery:
https://mesoblast.com/images/pdf/Psaltis_et_al_JACC_CV_Interventions_2010.pdf
Transendocardial cell delivery.
Although myocardial cell retention is suboptimal with all delivery routes thus far examined, studies suggest that superior results are obtained when cells are delivered by direct intramyocardial injection, compared with intracoronary or peripheral venous infusion (24,25). This is highly relevant in NICM, where the recruitment of exogenous cells across the myocardial vascu- lar bed may be limited by a paucity of inflammatory, homing signals (26). Furthermore, the safety of intracoronary ad- ministration of MSC/MPC remains contentious as the physical properties of these cells may result in occlusion of the coronary microvasculature (24). For these reasons, we administered cells by direct, intramyocardial injection, adopting a catheter-based, transendocardial approach, due to it being less invasive and more clinically relevant than open, transepicardial injection. We used 3-dimensional electromechanical navigation to target unhealthy myocar- dium (21) and achieve multisegmental distribution of injec- tions to enhance the prospects of achieving global LV repair.