Endothelial Progenitor Cell Capture in Drug-Eluting Stents

Study Questions:

What is the efficacy of a sirolimus-eluting stent combined with a bioabsorbable polymer coated with an antibody designed to capture endothelial progenitor cells (Combo stent)?


In the Japan-USA HARMONEE study, 572 stable coronary artery disease (CAD) patients with 675 significant coronary lesions were randomized to receive the Combo stent or an everolimus-eluting stent (EES). At 1 year, patients underwent coronary angiography with fractional flow reserve. The first 140 subjects also underwent optical coherence tomography (OCT) to assess stent strut coverage.


Target vessel failure (TVF) occurred in 7.0% of the Combo stents versus 4.2% of the EES, which met the noninferiority hypothesis (p = 0.02). Quantitative coronary angiography late loss with Combo was equivalent to EES, while OCT-determined strut coverage was superior for Combo stents (91.3% vs. 74.8% in EES, p < 0.001). One stent thrombosis was observed in the EES group.


The authors concluded that the Combo stent demonstrated noninferior 1-year TVF and late loss in a randomized comparison to EES, with superior strut-based tissue coverage by OCT.


Drug-eluting stents have represented a major breakthrough by markedly reducing restenosis rates following coronary stenting. Although local release of mTORC1 inhibitors has been highly successful in reducing exuberant proliferative responses to vascular injury, they also impair stent coverage by endothelial cells, extending the risk for stent thrombosis and necessitating prolonged dual antiplatelet therapy (DAPT). The Combo stent was thus designed with an anti-CD34 antibody coating to capture circulating endothelial progenitor cells with hopes of promoting re-endothelialization. Previous preclinical porcine studies enabling both OCT and histological assessment of stents at various time points following deployment demonstrated that the Combo platform promoted endothelialization while reducing neointimal formation and inflammation. Whether this promising technology will lead to superior clinical outcomes, and possibly reduced need for prolonged DAPT, will require further study, including high-risk patients.

Clinical Topics: Acute Coronary Syndromes, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Atherosclerotic Disease (CAD/PAD), Interventions and ACS, Interventions and Coronary Artery Disease, Interventions and Imaging, Angiography, Nuclear Imaging

Keywords: Acute Coronary Syndrome, Coronary Angiography, Coronary Artery Disease, Drug-Eluting Stents, Endothelial Cells, Fractional Flow Reserve, Myocardial, Inflammation, Myocardial Ischemia, Neointima, Polymers, Sirolimus, Stents, Thrombosis, Tomography, Optical Coherence, Vascular Diseases

< Back to Listings