Skeletal Myoblast Cells

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Skeletal myoblasts

• Derived from satellite cells in skeletal muscle

• With appropriate stimulus, satellite cells differentiate into muscle fibers

• Highly resistant to ischemia

• Do not contract spontaneously

• Do not differentiate into cardiomyocytes

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Human skeletal myoblasts after 3-wk in vitro culture period (magnification ×40)

Skeletal myoblasts

2-3 cm biopsy sample of thigh vastus lateralis (12-18 g) explanted under local anesthesia

Courtesy of Arshed A. Quyyumi, MD.

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Before surgery After surgery

Menasché P et al. Lancet. 2001;357:279-80.

Skeletal myoblast transplantation in post-MI HF patients

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Autologous skeletal myoblast injection for ischemic cardiomyopathy trial (MAGIC)

• Patients:– Moderate to severe LVSD referred

for CABG

• Cells:– Muscle Bx from thigh– Skeletal muscle myoblasts cultured

• Delivery:– Direct injection into scar at surgery

• Results:– Stopped early by DSMB due to low enrollment rate– Adverse event rate similar (25% cells vs 20% controls)– ICD Therapy in 15%– No improvement in LVEF by TTE (primary outcome)*– LVEF improved by SPECT– Highly significant dose-dependent LV size decrease

Cleland JGF et al. Eur J Heart Failure 2007;9:92-97.

PlaceboLow-Dose Myoblasts

High-Dose Myoblast P value

Patients enrolled

41 39 40

Patients injected

34 33 30

Change in LVEF (echo)*

+4.4% +3.4% +5.2% NS

Change in LVEF (nuc)

0 2% 3% <0.04

Change in LVEDD (mL)

+9 (-21 to 28)

-9 (-33 to 25)

-23 (-42 to 0)

0.006