Abluminal Neointimal Healing by Optical Coherence Tomography Assessment After Drug-Eluting Stent Implantation on Organized Recanalized Thrombus

J INVASIVE CARDIOL 2017;29(11):E161-E162.

Key words: recanalization, thrombus, cardiac imaging, optical coherence tomography

A 56-year-old male smoker with hypertension was admitted with lateral ST-elevation myocardial infarction. Coronariography showed a thrombotic occlusion of the circumflex artery (CX) solved with two overlapped drug-eluting stents. Multiple irregular linear filling defects and intraluminal haziness on proximal and mid left descending artery (LAD), mimicking a spontaneous dissection (Figure 1A and Video 1), were shown. Therefore, an optical coherence tomography (OCT) was performed on the LAD (Figure 1B and Video 2); OCT showed multiple small channels divided by thin septa communicating with each other in a “Swiss cheese” appearance, corresponding with a recanalization of organized thrombi. Upon re-interrogating the patient, he referred to an episode of chest pain 3 years ago and stable angina since then. A functional assessment showed a reduced fractional flow reserve of 0.75, so percutaneous coronary intervention was planned. After predilation, a long drug-eluting stent guided by the OCT measurements was implanted (3.5 x 44 mm BioMime; Meril). Even after aggressive postdilations with a 4.5 NC balloon (Boston Scientific), there was some peristent contrast staining (Figure 1C) corresponding with previous circular channels on OCT crushed against the vessel wall with a demilune appearance (Figure 1D and Video 3; Figure 2). 

At 6-month follow-up exam, angiography showed patent LAD and CX stents without restenosis and less peristent contrast staining (Figure 1E). OCT revealed a well-expanded and apposed stent. Almost all abluminal cavities were completely filled or smaller (Figure 1F and Video 4); we surmise that this was probably due to a neointimal healing process.

Recanalization of organized thrombi is a rare and probably misdiagnosed condition after acute coronary syndromes.¹ Typical findings by OCT are multiple small channels, with most showing functional significance.¹

Although a few cases have been reported where PCI was performed with OCT guidance, none of them describe these findings.² This pattern appears after crushing the septa of the small channels, leaving small cavities in a demilune shape between the abluminal part of the stent and the vessel wall. These findings may resemble acute stent malapposition, but with a well-expanded stent and apposition.

The neointimal healing process after stenting has been extensively studied in bare-metal and drug-eluting stent implantation.² However, almost all our knowledge about the healing process is limited to the adluminal side of the struts. Most of the malapposed and side-branch struts are covered on the abluminal side 6 months after bioresorbable vascular scaffold and second-generation drug-eluting stent implantation, with thicker neointimal coverage than on the adluminal side.² Although the optimal management is still unknown, this might be one of the scenarios where prolonged dual-antiplatelet therapy would be justified.

View Videos 1-4 

References

1.    Kang SJ, Nakano M, Virmani R, et al. OCT findings in patients with recanalization of organized thrombi in coronary arteries. JACC Cardiovasc Imaging. 2012;5:725-732.

2.    Ishida K, Otsuki S, Giacchi G, et al. Serial optical coherence tomography assessment of malapposed struts after everolimus-eluting stent implantation. A subanalysis from the HEAL-EES study. Cardiovasc Revasc Med. 2017;18:47-52.

From the Cardiology Department, University Hospital Juan Ramón Jiménez, Huelva, Spain.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript accepted April 24, 2017.

Address for correspondence: Santiago J. Camacho Freire, MD, Ronda Norte S/N Secretaria de Hemodinámica, 1st Floor University Hospital Juan Ramón Jiménez, 21005 Huelva, Spain. Email: navallana@hotmail.com