Abstract 1861: Myocardial Assistance by Grafting a New Bioartificial Upgraded Myocardium (MAGNUM Clinical Trial): One Year Outcome
Objectives Cell transplantation for myocardial regeneration is limited by poor graft viability and low cell retention. In addition, in ischemic cardiomyopathy the extracellular matrix is deeply altered. Therefore it could be important to associate a procedure aiming at regenerating myocardial cells and restoring the extracellular matrix function. We evaluated intrainfarct stem cell therapy associated with a cell-seeded collagen scaffold grafted onto infarcted ventricles.
Methods In 15 patients (aged 54.2±3.8 years) presenting LV postischemic myocardial scars (age of the infarcts 8.2±3.5 months) and with indication for a single OP-CABG, bone marrow was collected by aspiration from the iliac crest. The cell suspension was loaded on Ficoll-Paque density gradient and 300 ± 28 million mononuclear bone marrow cells (BMC) were implanted during surgery in the scar. A type I collagen matrix seeded with the same number of BMC (300 ± 28 million cells) was added on top of the scarred area and fixed onto the epicardium by 6 single PDS sutures and covered by a second non-cellularized matrix.
Results There was no mortality and any related adverse events (follow-up 15±4.2 months), no malignant cardiac arrhythmias were reported, no patient was lost to follow-up. NYHA FC improved from 2.3±0.5 to 1.4±0.3 (p=0.005). LV end-diastolic volume evolved from 142±24 to 117±21mL (p=0.03), LV filling deceleration time improved from 162±7ms to 196±8ms (p=0.01). Scar area thickness progress from 6±1.4 to 9±1.5mm (p=0.005). EF improved from 25±7 to 33±5% (p=0.04).
Conclusions Simultaneous intramyocardial injection of BMC and fixation of a cell seeded matrix onto the epicardium is feasible and safe. The cell seeded collagen matrix seems to increase the thickness of the infarct scar with viable tissues and help to normalize cardiac wall stress in injured regions, thus limiting ventricular remodelling and improving diastolic function. Functional improvements can not be conclusively related to the cells and matrix due to the association of CABG. Cardiac tissue engineering seems to be a promising way for the creation of “bioartificial myocardium”. Efficacy and safety of this approach should be evaluated in a large randomized controlled trial.