Long term follow-up after intramyocardial stem cell therapy with AC133+ bone marrow cells

Objective: Since early benfits of cardiac stem cell therapy are reported the results have to be differentially interpreted with respect to patient selection, cell-type, cell-origin and mode of delivery to the heart. The long term effects and side-effects of this therapy, however, are unknown. Here we present the long term follow-up data after intramyocardial injection of AC133+ bone marrow cells.

Methods: Long term follow-up data of 27 patients (female/n=2) after surgical intramyocardial stem cell treatment were analyzed with focus on myocardial function and treatment-related safety. Data were assessed by clinical re-admission for about 3 days. Quality of life (SF36), exercise testing (6-minute walk test), left ventricular function (Echocardiography, cardiac-MRI), cardiac arrhythmia (ECG/Holter-ECG), myocardial calcification and malformation (cardiac-CT) as well as occurrence of adverse cardiac events were determined.

Results: Cumulative time of follow-up was 843 patients months (range: 6–63). While median LV-EF was increased (3±9%; positive change in 63% of cases) compared to preoperative values, patients gained from therapy in physical ability and quality of life (SF36: 28.6 points/optimum 0–21 points). 2 patients were re-admitted for coronary intervention. No further therapy related cardiac adverse events were documented. Cardiac CT and MRI showed no signs for malformation. In one case a slight intramyocardial calcification beside the injected area was detected.

Conclusion: Before phase 3 clinical studies, there is no concern about long term safety and effectiveness of intramyocardial stem cell therapy in combination with cardiac surgery.