Objective To evaluate the risk of ventricular arrhythmias (VAs) after MSC transplantation in swine model with acute myocardial infarction.
Methods Swine models with myocardial infarction were created by intracoronary balloon occlusion and then received MSC solution or 0.9% sodium chloride solution via balloon catheter. 6 weeks after artery occlusion, heart rate turbulence (HRT), dispersion of APD and RT (APDd and RTd), slope of APD reconstitution curve, Threshold cycle length of APD alternan and cardiac electrophysiologic study (EPS) were used to evaluated the VAs risks. Haemodynamic study was assessed to evaluate the cardiac performances. The concentrations of collagen in non-infarcted myocardium was assayed to elucidate the degree of myocardial remodelling.
Results There were significantly abnormality of turbulence onset (TO) and turbulence slope (TS) in MI group relative to control group (p<0.01). MSC transplantation could ameliorate the abnormal HRT (MSC group vs MI group, p<0.01). The values of APD90, APDd, RT and RTd in the MI and MSC group markedly increased compared with the control group (p<0.01). These parameters in the MSC group were significantly lower than MI group (p<0.05). The slope of reconstitution curve in the MSC group was higher than control group but lower than MI group. The threshold cycle length of APD alternan in the MSC group was remarkably higher than that in the control group (p<0.01) and lower than that in the MI group (p<0.05). Inducible malignant VAs in the MSC group were remarkable lower than that in the MI group (30.8% vs 70.0%). MSCs therapy markedly improve impaired cardiac performances and reduce fibrosis deposition after MI.
Conclusions MSC intracoronary infusion does not cause proarrythmogrenic risk but tent to reduce the risk of malignant VAs. MSC therapy might be emerge as a new, safe and effective preventive strategy against VAs besides improving cardiac performance in ischaemic heart disease.