Key result
Intramyocardial injection of MSC or MNC did not increase endocardial electrogram fragmentation or duration, but attenuated myocardial fibrosis (13.6% MSC vs 28.7% control; P=0.013).
Why the study?
Does intramyocardial injection of mesenchymal or mononuclear stem cells increase proarrhythmogenic electrogram changes in a porcine model of chronic ischemic myocardium?
Does intramyocardial injection of mesenchymal or mononuclear stem cells increase proarrhythmogenic electrogram changes in a porcine model of chronic ischemic myocardium?
Intramyocardial injection of MSCs or MNCs in ischemic myocardium attenuates ischemic damage without creating an electrophysiological substrate for reentry tachycardias in a porcine model.
No proarrhythmic substrate with MSC/MNC injection in porcine ischemia; leaves open human safety and efficacy trials.
BACKGROUND: Cell injection therapies have been introduced for the treatment of patients with coronary heart disease. However, intramyocardial injection of bone marrow (BM)-derived cells may generate proarrhythmogenicity. METHODS: Two weeks after the placement of a circumflex artery-ameroid constrictor, 21 pigs received mesenchymal stem cells (MSC, n = 9), mononuclear (BM)-derived stem cells (MNC, n = 6), and placebo (n = 6) using a electromechanical mapping (EMM)-guided percutaneous transendocardial injection catheter. At week 6, EMM was repeated and the injected areas were analyzed in detail to evaluate local bipolar electrogram fragmentation, duration, and amplitude. Myocardial fibrosis was evaluated by a quantitative histological analysis. RESULTS: At week 6, the injection of MSC or MNC did not increase local electrogram fragmentation (MSC group: 1.4 +/- 0.3 vs. 1.3 +/- 0.2; MNC group: 1.4 +/- 0.2 vs. 1.3 +/- 0.2; P = NS), prolong electrogram duration (MSC group: 27.1 +/- 7.8 ms vs. 23.7 +/- 2.0 ms; MNC group: 27.8 +/- 3.5 ms vs. 26.8 +/- 5.6 ms; P = NS), or decrease bipolar voltages (MSC group 2.7 +/- 0.9 mV vs. 2.8 +/- 1.0 mV; MNC group 2.0 +/- 1.0 mV vs. 1.7 +/- 0.4 mV). From week 2 to week 6, mean left ventricular ejection fraction increased in the MSC group (37.9 +/- 4.2% vs. 45.9 +/- 2.2%; P = 0.039) only. Histological analysis of the ischemic regions revealed 17.6 +/- 5% myocardial fibrosis in the MNC group vs. 13.6 +/- 3.4% MSC vs. 28.7 +/- 8.7% in the control group (P = 0.038 and P = 0.013). No death occurred in any animal after the injection procedure. CONCLUSION: Intramyocardial injection of MSC or MNC do not increase fragmentation and duration of endocardial electrograms in the injected ischemic myocardium but attenuate ischemic damage and therefore may not create an electrophysiological substrate for reentry tachycardias.
No takes yet. Share an insight, caveat, or question.
Krause et al. (2009) studied Chronic ischemic myocardium (n=21). Mesenchymal stem cells (MSC) or mononuclear stem cells (MNC) vs. Placebo was evaluated on Local bipolar electrogram fragmentation, duration, and amplitude (p=NS). Intramyocardial injection of MSC or MNC did not increase endocardial electrogram fragmentation or duration, but attenuated myocardial fibrosis (13.6% MSC vs 28.7% control; P=0.013).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: