Abstract 12659: Autologous Mesenchymal Stem Cells Produce Concordant Improvements in Regional Function, Tissue Perfusion, and Fibrotic Burden when Administered to Patients Undergoing Coronary Artery Bypass Grafting
Background: There is evidence supporting the efficacy of cell-based therapy to improve LV function in patients with chronic ischemic cardiomyopathy undergoing CABG. The precise impact of this strategy and of the site of injection remains controversial. We tested the hypothesis that intramyocardial injections of autologous MSCs have a concomitant impact on cardiac structure and function that is highly dependent on the site of cell injection.
Methods and Results: Nine patients were injected with autologous MSCs or placebo into akinetic/hypokinetic territories not undergoing revascularization. We performed cardiac MRI to measure wall thickness, contractility, scar size and perfusion at baseline and after 3, 6 and 18 months and delineated myocardial segments that were i.) untreated, ii.) injected but not revascularized and iii.) revascularized only. A concordant improvement score was measured encompassing all variables (range -5 to 5). At 18 months, subjects receiving MSCs (n=6) exhibited decreased scar mass (-30.45±5.6%; p=0.005), increased viable tissue (22.65±8.7%; p=0.03) and improved contractility (64.89±22.45%; p=0.045) compared to baseline (Fig 1 A,B). Segmental analysis revealed that the injected segments showed a concordant reduction in scar size, improvement in contractility and perfusion (score: 3.53±0.56) whereas non-injected revascularized segments demonstrated non-concordant changes (score: 0.29±0.45, p=0.002) (Fig.1 C). There was a location dependent drop-off in improvement as a function of distance from the site of injection (Fig 1D).
Conclusions: These findings demonstrate that intramyocardial injection of autologous MSCs to akinetic yet non-revascularized segments produces comprehensive regional functional restitution. The recovery is dependent on actual sites of injection. These findings have important therapeutic and mechanistic implications.
- © 2013 by American Heart Association, Inc.