In a previous phase I trial, epicardial injection of myoblasts was shown to be feasible, lead author Dr. Nabil Dib, from the University of California, San Francisco, and colleagues note. Whether a catheter could be used for myoblast delivery, however, was unclear.
Unlike delivery with epicardial injection, catheter-based transplantation can be used in high-risk patients. Moreover, the procedure is repeatable and may reduce morbidity and mortality, according to the report in the Journal of the American College of Cardiology: Cardiovascular Interventions for January.
The Catheter-based delivery of Autologous Skeletal Myoblasts for Ischemic Cardiomyopathy (CAuSMIC) study included 23 subjects with a prior MI, heart failure, and a New York Heart Association functional class of II to III. The subjects were randomized to receive maximal medical therapy with or without autologous myoblast transplantation via catheter.
Myoblast transplantation was performed with the Biosense-NOGA (Diamond Bar, California) 3-D-guided endomyocardial delivery system. Heart function, quality of life and other outcomes were compared at baseline and at 1-year follow-up.
No significant differences in safety outcomes, including arrhythmias and death, were noted between the two study groups, the report shows.
Autologous myoblast transplantation-treated patients showed sustained improvements in heart function (p < 0.0004) and quality of life (p = 0.004) compared with the controls.
Echocardiographic testing showed greater reductions in end diastolic diameter and end systolic diameter in the transplant group, although the differences fell short of statistical significance. Enhanced voltage changes were also seen among those who underwent autologous myoblast transplantation.
“Training will be a key factor in the success of (catheter-based myoblast transplantation), because not all studies have shown similar freedom from complications as shown here,” the authors emphasize. “Larger, randomized, double-blind, placebo controlled and multicenter clinical trials are warranted to further test this therapeutic approach.”
J Am Coll Cardiol Intv 2009;2:9-16.