Comment on: Distal coronary artery abnormalities in Kawasaki disease: experience on CT coronary angiography in 176 children: reply

Dear Editor, We thank Maccora et al. [1] for their interest in our manuscript [2] on distal coronary artery abnormalities (CAAs) in children with Kawasaki disease (KD) using radiation-optimized CT coronary angiography (CTCA).

Development of CAAs is the most important complication in children with KD. Therefore detailed assessment of coronary arteries is critical for decision making with regard to treatment and follow-up of these children.

We agree with the authors that transthoracic echocardiography (TTE) has hitherto been the imaging modality of choice for coronary artery assessment in KD. However, TTE has several inherent limitations and these have not been adequately highlighted in the published literature. For instance, it is difficult to assess middle and distal segments of coronary arteries on TTE. In our study we showed that CTCA clearly delineates the entire course of coronary arteries [2]. This is a major advantage of CTCA over TTE [3–5].

We wish to clarify that 23/176 (13.07%) patients in our cohort had shown CAAs in distal segments. Of these, four had shown distal segment involvement in the absence of any abnormalities in proximal segments. Similarly, distal extension of proximal CAAs was noted in 11 patients—this had been missed on TTE. Nine patients showed non-contiguous aneurysms in both proximal and distal segments. In addition, four patients showed distal segment CAAs in the absence of proximal involvement of the same coronary artery but with associated proximal involvement of another coronary artery [2]. These findings provide important insights into our understanding of CAAs in KD. It should be noted that treatment of KD depends upon the presence of CAAs, whether proximal, distal or both [2, 5].

Based on our experience over 8 years, we propose that CTCA be considered in all children with KD who have demonstrable CAAs on TTE. However, not all centres will agree with this viewpoint. CTCA can be performed during the acute stage and may be repeated on follow-up depending upon the imaging findings.

Radiation exposure on CTCA carried out on 128 slice dual-source CT scanners with radiation optimization strategies is very low (≤1 mSv at our centre). In our opinion, this is an acceptable level of radiation exposure inasmuch as CTCA provides crucial information on several aspects of coronary artery involvement (e.g. extent of CAAs, mural involvement, calcification, remodelling of aneurysms, thrombus and stenosis) that may be missed on TTE but which nevertheless impact treatment strategies in children with KD [2, 4].

Acknowledgements

All authors contributed equally.

Funding: No specific funding was received from any bodies in the public, commercial or not-for-profit sectors to carry out the work described in this article.

Disclosure statement: The authors have declared no conflicts of interest.

Data availability statement

All data are included within the text.

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