Catheter-based transendocardial delivery of autologous bone marrow-derived mononuclear cells in patients listed for heart transplantation

Background

Patients (patients) with end-stage ischemic heart failure (ESI-HF) with VO_2max < 14 ml/kg/min carry a very high mortality. Heart transplantation (HTx) improves the outcome of selected patients but, since it has limited epidemiological impact, alternative therapies have been explored. Intramyocardial injections of autologous bone marrow-derived mononuclear cell (BM-MNCs) have shown promising initial results regarding functional improvement. Therefore, we evaluated the outcome of BM-MNC transendocardial delivery in patients listed for HTx.

Methods

Five patients with ESI-HF (aged 54. 8 ± 8 years), presenting VO_2max < 14 ml/kg/min and already listed for HTx, were submitted to BM-MNC injections. Bone marrow was harvested from the iliac crest and BM-MNCs were selected by Ficoll gradient. Endocardial injections targeting hibernated myocardial areas were performed utilizing electromechanical mapping (MyoStar, Cordis, Miami Lakes, FL, USA). The Treadmill Test Ramp Protocol (TT) (five patients, baseline; four patients, 8 weeks; one patient, 24 weeks) as well as MIBI-SPECT and the two-dimensional echocardiogram Simpson's Method (baseline and 8 weeks) were also performed.

Results

A total of 30 × 10⁶ BM-MNC were injected at 15 sites in each patient. Left ventricular total reversibility (TR), percentual of myocardial rest defect at 50% and ejection fraction at baseline and 8 weeks. The results of TT are shown in Figure 1.

Figure 1

Conclusion

In this pilot study of BM-MNC endocardial injections, our data suggest that this procedure seems to be safe to be performed in this very sick population, and suggest an improvement in objective assays of myocardial perfusion and exercise capacity in some patients listed for HTx. Future studies must be conducted to evaluate the role of BM-MNC transplantation as an alternative therapy for these patients.