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

Dear Editor, We read with interest the recent article by Singhal et al. [1] outlining a novel approach to the assessment of coronary artery abnormalities (CAAs) in Kawasaki disease using CT coronary angiography (CTCA) for evaluation in distal segments.

Kawasaki disease is a common medium-vessel vasculitis that affects predominantly children, and if not properly recognized and treated may lead to CAAs in 15–25% of children [2]. Therefore, a tailored diagnosis and evaluation of disease severity is crucial to receiving the correct treatment and avoiding long-term damage, improving patients’ disease outcomes and quality of life.

Currently, the standard of care for the evaluation of CAAs is transthoracic echocardiography (TTE), which is a quick, inexpensive and repeatable method, without risk for the patient. However, as the authors clearly describe in their paper, it has several limitations: it is operator dependent, it has interobserver variability, it has a poor acoustic window in older children, and it has limited ability to evaluate distal coronary artery abnormalities [3].

Since the evaluation of CAAs in the distal segment is usually extremely difficult, and they are usually underrecognized, the authors reported their experience with CTCA, an emerging technique with high sensitivity and sensibility able to evaluate CAAs in patients with Kawasaki disease, with a low radiation exposure compared with conventional catheter coronary angiography [4].

In their cohort of 176 patients with Kawasaki disease on whom CTCA was performed, a total of 60 aneurisms were detected in 23 children. On TTE, only 40 aneurysms could be identified.

However, only 4 patients had distal aneurysms in the absence of any other CAAs, and an additional 4 children showed artery complications on CTCA over the follow-up, not identified by TTE. The authors assessed the ability of CTCA to detect distal aneurysms, missed by conventional TTE.

Although these data are very fascinating and provide new insight into this topic, some caveats arise. The characteristics of the included population (i.e. the 176 children with Kawasaki disease on whom CTCA was performed) are unclear. The evaluation of the characteristics of this population might help to identify those candidates with Kawasaki disease for whom it would be best to perform CTCA. In our opinion, this represents a key point in ascertaining the exact place of CTCA in Kawasaki disease diagnosis and follow-up.

Identifying a distal aneurysm in a child with Kawasaki disease otherwise without coronary involvement is highly likely to change their treatment in the clinical setting, and according to the authors’ data, this occurred in 2.2% of their cohort. The same can be said for the 4 patients for whom there were coronary complications missed at TTE (4/176, 2.2%).

On the other hand, would the CTCA data change treatment and follow-up for a child with Kawasaki disease who also had an aneurysm that had been detected by TTE? The authors claim that CTCA should be performed in selected children with Kawasaki disease who have CAAs on TTE, but the timing of the imaging is not discussed. Additionally, are we confident that all of the children with Kawasaki disease with CAAs should have CTCA, including those who promptly recover from CAAs after treatment?

In our opinion, CTCA surely represents a significant step forward in the diagnosis, treatment and follow-up of patients with Kawasaki disease; however, radiation exposure in childhood should be adequately justified by a well-defined clinical benefit. In particular, the at-risk population that requires exposure to a CTCA scan should be clearly identified.

In addition, we feel it would be mandatory to identify the exact timing of CTCA that would be of most benefit.

Clinical data, ultimately generating a dedicated score, will help to detect the specific population who will benefit from CTCA, thus balancing the risks and benefits. Early recognition of CAAs would result in earlier application of aggressive treatment with IVIG in association with glucocorticoids, in accordance with 2021 American College of Rheumatology recommendation [5].

Acknowledgements

All authors contributed to data acquisition and analysis, as well as drafting and critically appraising the manuscript.

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.

References