In an earlier post, I discussed the initial results of the SCIPIO clinical trial. This clinical trial extracts cardiac stem cells from the upper chambers of a heart attack patient’s heart. The cardiac stem cells are then cultured and reinjected back into the heart. The initial report was published in an internationally acclaimed medical journal called the Lancet.
The results were remarkable. After a heart attack, the heart usually deteriorates and undergoes remodeling. Remodeling consists of an enlargement of the heart, followed by congestive heart failure. However, those patients in the SCIPIO clinical trial who received transplants of their own cardiac stem cells (CSCs) showed significant improvements in heart function over those who received the placebo. Heart attack patients who had received CSC transplants showed shrinkage of their cardiac scars and greater ejection fractions.
Now a follow-up paper by the same research group has extended and confirmed these results.
In this paper, 33 patients were enrolled and of these patients, 20 were treated with their own CSCs and 13 served as controls. CSCs were isolated from each patient by means of a heart biopsy from the right atrial appendage during cardiac arterial bypass graft (CABG) surgery. These cells were harvested and processed during CABG surgery, but the harvesting of the CSCs did not increase the time required for CABG surgery.
CSC-treated patients showed a marked increase in the ejection fraction of the left ventricle. The ejection fraction is the percentage of blood pumped out of a filled ventricle by a heartbeat. After 4 months, the ejection fraction increased from 27.5±1.6% to 35.1±2.4% [P=0.004, n=8]. By 12 months after the procedure, the ejection fraction increased further to 41.2±4.5% [P=0.013, n=5]. This means that the efficiency with which blood is pumped by the heart increased after CSC infusions.
Secondly, the size of the infarct size was measured by a technique called “late gadolinium enhancement.” Gadolinium is a somewhat rare metallic element that us very useful because it is sensitive to electromagnetic resonance. Traces of it can be injected into the body to enhance the MRI pictures. Gadolinium also nicely outlines the noncontracting areas of the wall of the heart. MRIs after Gadolinium infusions revealed that the heart scars in those patients that had received CSC infusions had shrunk by -6.9±1.5 g [-22.7%] at 4 months [P=0.002, n=9] and -9.8±3.5 g [-30.2%] at 12 months [P=0.039, n=6]. The regions of the left ventricle (the main pumping chamber of the heart) that were dead also shrunk in CSC-treated patients. The dead regions shrunk -11.9±2.5 g [-49.7%] at 4 months [P=0.001] and -14.7±3.9 g [-58.6%] at 12 months [P=0.013]. Likewise, the total living mass of the left ventricle increased in CSC-treated patients: +11.6±5.1 g at 4 months after CSC infusion [P=0.055] and +31.5±11.0 g at 12 months [P=0.035].
This study confirms and extends the results of the initial report of SCIPIO. The isolation of CSCs during heart surgery is feasible and does not adversely affect CABG surgery. Also cardiac MRIs also reveal that CSC infusion produces a striking improvement in both global and regional function of the left ventricle. The CSCs also cause a reduction in infarct size, and an increase in viable tissue. These benefits persist for at least 1 year and are completely consistent with cardiac regeneration as a result of CSC infusion.
This is great news for heart attack patients.
See: Chugh AR, Beache GM, Loughran JH, Mewton N, Elmore JB, Kajstura J, Pappas P, Tatooles A, Stoddard MF, Lima JA, Slaughter MS, Anversa P, Bolli R. Administration of Cardiac Stem Cells in Patients With Ischemic Cardiomyopathy: The SCIPIO Trial: Surgical Aspects and Interim Analysis of Myocardial Function and Viability by Magnetic Resonance. Circulation. 2012 Sep 11;126(11 Suppl 1):S54-64.