The role of intracoronary infusion of autologous bone marrow cells in the management of acute myocardial infarction was examined in the ASTAMI trial.

The ASTAMI investigators limited enrollment to acute ST-segment elevation myocardial infarction patients with anterior wall involvement for 2 reasons:

(1) it is the region of the myocardium best visualized with noninvasive imaging and

(2) anterior wall myocardial infarctions are associated with a greater risk of post-myocardial infarction left ventricular dysfunction compared with isolated involvement of other walls.

A total of 101 patients with acute anterior MI who underwent successful primary percutaneous coronary intervention ( PCI ) were randomized either to intracoronary infusion of mononuclear bone marrow cells ( mBMC ) 5 to 8 days after PCI ( n = 52 ) or to control ( n = 49 ).

In contrast to the REPAIR-AMI trial, the control group did not undergo bone marrow aspiration or repeat cardiac catheterization.

Results of the 3 different imaging modalities showed no differences in ejection fraction between groups at baseline and 6 months' follow-up.
Ejection fraction improved in both groups as measured by single-photon emission computed tomography ( 8% mBMC vs 7% control, P = NS ), magnetic resonance imaging ( 1.2% mBMC vs 4.3% control, P = NS ), and echocardiography ( 3.1% mBMC vs 2.1% control, P = NS ).
There were also no differences in change in infarct size and end diastolic volume.
There were no deaths at 6 months, and adverse event rates did not differ between groups.

In contrast to the REPAIR-AMI trial and several other previously reported studies of bone marrow cell infusion in acute myocardial infarction, the ASTAMI trial found no benefit for intracoronary infusion of bone marrow mononuclear cells in patients after primary PCI for anterior myocardial infarction.
These discrepant results were noted despite generally similar study methods, including the types of cells used, as well as the timing and intracoronary delivery technique used.
Differences between the REPAIR-AMI and ASTAMI studies included the method of measurement of left ventricular function and location of myocardial infarction.

Although the results of the ASTAMI may have tempered the enthusiasm generated after the REPAIR-AMI trial, the role of stem cell therapy for cardiac repair remains promising.

Ketil Lunde, Rikshospitalet University Hospital, Oslo, Norway


Source: American Heart Journal, 2006


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