Abstract 2616: Mechanistic Insights from Serial Cardiac Magnetic Resonance Imaging at 3 and 15 months After Application of Blood-Derived Progenitor Cells in Recanalized Chronic Coronary Total Occlusions (CTO)
Background: Transplantation of circulating progenitor cells (CPC) was shown to improve left ventricular (LV) function after successful recanalization of CTO at short-term follow-up. Cardiac magnetic resonance imaging (CMRI) is an excellent diagnostic tool for serial assessment of changes in left ventricular function and might uncover underlying mechanisms by assessment of myocardial perfusion and infarct size at short-term and long-term follow-up.
Methods and results: Twenty-six patients with reperfused CTO were randomized to either CPC’s or inactive serum (control) infused into the target vessel. Serial CMRI performed at baseline, after 3 and 15 months revealed a significant increase in left ventricular (LV) ejection fraction in the CPC group (from 51±14 to 58±13% and 60±10%; p<0.01 versus baseline), a decrease in endsystolic volume (from 68±33 to 60±33 ml and 60±31 ml; p<0.05 versus baseline) and unchanged enddiastolic volumes (136±37 vs. 133±33 and 147±45, p=n.s. vs. baseline). Infarct size decreased significantly from 10.3±7.7 to 9.0±7.2 and 9.5±8.5 ml, p<0.05 vs. baseline. First-pass myocardial perfusion at rest and stress using adenosine revealed significant improvement of the myocardial perfusion reserve index in affected segments by 1.50±0.17 to 1.76±0.16 (p<0.001) and 1.82±0.20 (p<0.001) at 3 and 15 months, respectively. In control ejection fraction showed no increase at 3 (p=0.99) but delayed improvement at 15 months (p=0.04), whereas myocardial perfusion was improved at 3 (p=0.01) and 15 months (p=0.004) follow-up. There was an inverse relationship between infarct transmurality and regional functional improvement in control, whereas this effect was attenuated in the CPC group.
Conclusions: Analysis of serial CMRI suggests that intracoronary application of CPC post CTO recanalization is associated with improved myocardial perfusion, reduction in infarct size and subsequent improved recovery of LV function as compared to control at mid-term and long-term follow-up.