Spontaneous Recanalized Chronic Total Occlusion or Recanalized Thrombus—What Are the Differentials?

Dear Editor:

We read the article regarding spontaneous recanalized chronic total occlusion by Akhtar Z, et al,¹ published in the April 2022 issue of the Journal of Invasive Cardiology, with great interest. We wish to comment on certain points to add to the scientific value of the index publication.

A chronic total occlusion (CTO) is defined as a 100% occlusion of the arterial segment with non-collateral Thrombolysis in Myocardial Infarction (TIMI)-0 antegrade flow, of at least 3-month duration.² In the absence of an old angiogram of occluded proximal right coronary artery (RCA) having TIMI-0 flow, and the present angiogram showing TIMI-3 flow, the authors’ assumption of a CTO that spontaneously recanalized over the time is incorrect.¹ A so-called “spontaneous recanalized CTO” as presented by the authors is not an actual CTO, but a functional occlusion.² The unusual angiographic appearance of the RCA having TIMI-3 flow¹ was suggestive of either a coronary dissection or recanalized thrombus,³ and not a CTO. Optical coherence tomography (OCT) confirmed the recanalized thrombus by its “Swiss cheese” or “honeycomb” appearance of multiple intraluminal channels³ and not the spontaneous recanalized CTO.¹ Retrospectively, RCA with TIMI-3 flow without any significant angiographic stenosis, negative cardiac markers, possibly old electrocardiographic changes, and a recanalized old thrombus on OCT makes the index case a low-risk, instead of high-risk, acute coronary syndrome. Determining the functional significance of the RCA lesion by fractional flow reserve or scintigraphy^4,5 could have provided additional value for the interventional management of the index case, which otherwise was medically managed without assessing the significance of multiple microchannels at the proximal, dominant RCA. Lastly, we question whether the thrombotic occlusion of the RCA was because of atherothrombosis or thromboembolism of the both RCA and pulmonary circulation. The index case needs a detailed evaluation of the hypercoagulable state to explain thrombosis of both the pulmonary and coronary circulation.

References

1. Akhtar Z, Kontogiannis C, Sharma S. Coronary caverns: spontaneous recanalized chronic total occlusion with multiple microchannels. J Invasive Cardiol. 2022;34(4):E347.

2. Stone GW, Kandzari DE, Mehran R, et al. Percutaneous recanalization of chronically occluded coronary arteries: a consensus document: part I. Circulation. 2005;112(15):2364-2372. doi:10.1161/CIRCULATIONAHA.104.481283

3. Vijayvergiya R, Kasinadhuni G, Revaiah PC, Sharma P, Kumar B, Gupta A. Role of intravascular imaging for the diagnosis of recanalized coronary thrombus. Cardiovasc Revasc Med. 2021;32:13-17. Epub 2020 Dec 30. doi:10.1016/j.carrev.2020.12.031

4. 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(7):725-732. doi:10.1016/j.jcmg.2012.03.012

5. Xu T, Shrestha R, Pan T, et al. Anatomical features and clinical outcome of a honeycomb-like structure in the coronary artery: reports from 16 consecutive patients. Coron Artery Dis. 2020;31(3):222-229. doi:10.1097/MCA.0000000000000822

From the Department of Cardiology, Post Graduate Institute of Medical Education & Research, Chandigarh, India.

Address for correspondence: Prof (Dr) Rajesh Vijayvergiya, MD, DM, FSCAI, FACC, FESC, FISES, Department of Cardiology, Advanced Cardiac Centre, Post Graduate Institute of Medical Education & Research, Sector 12, Chandigarh – 160 012, India. Email: rajeshvijay999@hotmail.com. Twitter: @DrRajeshVijay