Role of Cardiopulmonary Bypass and Arrested Heart Status in the Early Cell Distribution after Intracoronary Infusion of Bone Marrow Stromal Cells

A pilot trial of autologous bone marrow mononuclear cell transplantation through grafting artery: a sub-study focused on segmental left ventricular function recovery and scar reduction

BACKGROUND

Our preliminary study suggested that patients with chronic myocardial infarction (MI) and heart failure could potentially benefit from CABG combined with aBM-MNC by improving global left ventricular (LV) function. The purpose of this sub-study was to quantitatively evaluate the effectiveness of aBM-MNC transplantation during CABG in patients with chronic MI by intensively analyzing the global and segmental LV function, the scar, and the relationships between the function recovery and the scar transmural extent.

METHODS

A randomized, double-blinded, placebo-controlled study was performed in 50 patients with chronic MI. The patients were randomly allocated into CABG with stem cell transplantation (group A) and CABG only (group B) groups. CMR assessments of global and segmental left ventricular function and scar tissue were performed before surgery and repeated at 12 months after CABG and aBM-MNC transplantation.

RESULTS

The left ventricular ejection fraction (LVEF) improved by 13.5% and 8.0% in group A and B respectively (P=0.04). Segmental analysis of regional LV function recovery indicated that more improvement in contractility was found in group A within the same degree of the infarct transmurality (P=0.017) and showed a predominant interaction in the most severely affected segments (76-100%, P=0.016). Decrease in infarct size between the two groups did not reach statistical difference (9.4% vs. 6.0%, P=0.100).

CONCLUSIONS

CMR assessments revealed reversed ventricular remodeling and improved systolic function and scar reduction in patients who underwent aBM-MNC transplantation during CABG. And the conjunctional use of CABG and stem cell therapy could improve the left ventricular function in patients with chronic MI.

Isolated coronary artery bypass graft combined with bone marrow mononuclear cells delivered through a graft vessel for patients with previous myocardial infarction and chronic heart failure: a single-center, randomized, double-blind, placebo-controlled clinical trial

OBJECTIVES

This study aimed at examining the efficacy of bone marrow mononuclear cell (BMMNC) delivery through graft vessel for patients with a previous myocardial infarction (MI) and chronic heart failure during coronary artery bypass graft (CABG).

BACKGROUND

Little evidence exists supporting the practice of BMMNC delivery through graft vessel for patients with a previous MI and chronic heart failure during CABG.

METHODS

From November 2006 to June 2009, a randomized, placebo-controlled trial was conducted to test the efficacy and safety of CABG for multivessel coronary artery disease combined with autologous BMMNCs in patients with congestive heart failure due to severe ischemic cardiomyopathy. Sixty-five patients were recruited, and 60 patients remained in the final trial and were randomized to a CABG + BMMNC group (n = 31) and a placebo-control group (i.e., CABG-only group, n = 29). All patients discharged received a 6-month follow-up. Changes in left ventricular ejection fraction from baseline to 6-month follow-up, as examined by magnetic resonance imaging, were of primary interest.

RESULTS

The overall baseline age was 59.5 ± 9.2 years, and 6.7% were women. After a 6-month follow-up, compared with the placebo-control group, the CABG + BMMNC group had significant changes in left ventricular ejection fraction (p = 0.029), left ventricular end-systolic volume index (p = 0.017), and wall motion index score (p = 0.011). Also, the changes in the distance on the 6-min walking test as well as B-type natriuretic peptide were significantly greater in the CABG + BMMNC group than in the control group.

CONCLUSIONS

In summary, patients with a previous MI and chronic heart failure could potentially benefit from isolated CABG (i.e., those who received CABG only) combined with BMMNCs delivered through a graft vessel. (Stem Cell Therapy to Improve Myocardial Function in Patients Undergoing Coronary Artery Bypass Grafting [CABG]; NCT00395811).

Impact of Escaped Bone Marrow Mesenchymal Stromal Cells on Extracardiac Organs after Intramyocardial Implantation in a Rat Myocardial Infarction Model

Cell escape occurs after intramyocardial injection for treatment of myocardial infarction (MI) and then the migrated cells might be entrapped by extracardiac organs. We investigated the fate of migrated bone marrow-derived mesenchymal stromal cells (MSCs) and their impact on lung, liver, and spleen. MI model was created by coronary artery ligation in female Lewis rats. Three weeks after the ligation, bromodeoxyuridine (BrdU)-labeled male MSCs were directly injected into the infarcted area in the cell transplantation group ( n = 22). The same volume of phosphate-buffered solution (PBS) was injected in the control group ( n = 21). In the sham group ( n = 10) intramyocardial injection of the same volume of PBS was performed in healthy rats. Four weeks later, echocardiography was performed and the cell retention was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemistry study was performed to identify the migrated cells. Heart function was improved after the cell injection. qRT-PCR results showed the percentage of retained cells in heart, spleen, liver, and lung ranked 3.63 ± 0.48%, 0.77 ± 0.13%, 0.68 ± 0.10%, 0.62 ± 0.11%, respectively, after cell transplantation. The implanted MSCs that escaped to liver, spleen, and lung did not differentiate into fibroblast, myofibroblast, or alveolar epithelial cells. However, the migrated MSCs in liver expressed functional hepatocyte marker. In conclusion, cell migration after intramyocardial injection did not result in deterioration of lung, liver, and spleen function. Our study might pave the way for new safety investigation of emerging cell resources and their impact on target and untargeted organs.