High-Risk Atherosclerotic Plaque in Aberrant Circumflex Coronary Artery

J INVASIVE CARDIOL 2018;30(3):E26.

Key words: virtual histology intravascular ultrasound, computed tomography coronary angiography

A 45-year-old man presented after an episode of central chest pain. There were no localizing ischemic features on the electrocardiogram, but the troponin T was elevated at 25 ng/L after 12 hours. Catheter angiography revealed the presence of an aberrant circumflex artery and high-grade stenosis in the mid right coronary artery and proximal circumflex artery (Figure 1A); both lesions were treated with percutaneous angioplasty and stent implantation. Computed tomography angiography confirmed the aberrant circumflex arising from the ostium of the right coronary artery and then following a retroaortic course (Figure 1B). Previous case series have suggested that the retroaortic portion of aberrant circumflex arteries may be particularly prone to the development of atherosclerosis.¹ Virtual histology intravascular ultrasound (VH-IVUS) analysis of both lesions demonstrated a greater percentage of necrotic core in the aberrant circumflex (53%) (Figure 1D) than in the right coronary artery (32%) (Figure 1C). In addition, the ratio of necrotic core to dense calcium (a factor previously associated with high-risk plaque)² was twice as high in the plaque in the aberrant circumflex (5.4) as in the right coronary artery (2.7). 

References

1.    West NE, McKenna CJ, Ormerod O, Forfar JC, Banning AP, Channon KM. Percutaneous coronary intervention with stent deployment in anomalously arising left circumflex coronary arteries. Catheter Cardiovasc Interv. 2006;68:882-890.

2.    Missel E, Mintz GS, Carlier SG, et al. Necrotic core and its ratio to dense calcium are predictors of high-risk non-ST-elevation acute coronary syndrome. Am J Cardiol. 2008;101:573-578.

From the ¹Morriston Hospital, ABM University Health Board, Swansea, United Kingdom; ²University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom; ³University of Cambridge, Cambridge, United Kingdom; and ⁴Papworth Hospital NHS Foundation Trust, Cambridge, United Kingdom.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr West reports grant funds and personal fees from Abbott Vascular; personal fees from Boston Scientific and Plaquetec Ltd. The remaining authors report no conflicts of interest regarding the content herein.

Manuscript accepted June 15, 2017. 

Address for correspondence: Daniel R. Obaid, PhD, Department of Cardiology, ABM University Health Board, Morriston Hospital, Swansea SA6 6NL, United Kingdom. Email: Daniel.R.Obaid@wales.nhs.uk