Optical Coherence Tomography Findings at 5-Year Follow-Up After Coronary Stent Implantation
Optical coherence tomography (OCT) is an in vivo, high-resolution imaging modality (resolution, 12 μm; wavelength, 1300 nm; probe size, 0.018 inch; Lightlab Imaging). The principle is analogous to that of pulse-echo ultrasound imaging; however light is used rather than sound to create the image. The case presented illustrates the 5-year follow-up examination after bare metal stent implantation (Figure 1). Intravascular ultrasound imaging (IVUS) shows concentric, moderate neointimal hyperplasia (Figure 2). Intravascular OCT provides detailed visualization of the individual stent struts, neointimal proliferation, and neovascularization that is missed by IVUS (Figure 3).
Intraplaque hemorrhage through the neovascular bed is hypothesized to promote plaque growth. Although neovascularization, particularly when adjacent to stent struts, is a common finding in experimental animal models, to date only sparse data based on postmortem case reports are available in humans.1 The incidence, distribution, and time course are unknown. Our findings present strong evidence for the visualization of neovascularization in a living patient, which cannot be achieved with any other in vivo imaging modality to date.