Stress perfusion cardiac magnetic resonance imaging to identify coronary aneurysms, ischaemia and fibrosis in adult patients with convalescent Kawasaki disease

Background Kawasaki disease is a common cause of coronary aneurysms in early adulthood. Non-invasive imaging plays a crucial role in the diagnosis and surveillance of these patients who are known to develop ischaemia, premature coronary artery disease and have poorer long-term health outcomes. Stress perfusion cardiac MRI (CMR) is considered the “gold standard” for the assessment of ischaemia and risk stratification of major adverse cardiovascular events in patients with coronary artery disease. Its use in the long-term follow-up of patients with Kawasaki disease is particularly attractive as it avoids the use of ionising radiation. However, data on its utility, together with magnetic resonance angiography (MRA) and late gadolinium enhancement (LGE) to identify ischaemia, coronary aneurysms, and fibrosis, over long-term follow-up in this population remains limited. Purpose To evaluate the diagnostic utility of comprehensive non-invasive stress perfusion CMR to identify inducible ischaemia, coronary aneurysms and myocardial fibrosis in adult patients with convalescent Kawasaki disease. Methods We performed a retrospective review of all adult patients in our Kawasaki service who underwent stress perfusion CMR with MRA and LGE as part of routine clinical care. Data collected included the presence of inducible perfusion defects, coronary anatomy and LGE. Data was compared to contemporary CT coronary angiography (CTCA). In patients who had repeated stress perfusion CMR, changes in perfusion over time were investigated. Results Seventeen patients underwent stress perfusion CMR (total 30 scans). Seven patients underwent ≥2 scans. Median age was 21 years; 14 patients were male. Five patients (30%) had areas of inducible hypoperfusion of which 3 also had LGE. A further 2 patients had LGE with no ischaemia. Coronary MRA was performed in 12 patients (71%) and identified 14 aneurysms. In 8 patients with both MRA and CTCA, detection of aneurysms was significantly correlated (Pearson's coefficient 0.776; P value 0.024). Of the 5 patients with ischaemia, 4 patients had previous CABG. All areas of ischaemia corresponded to persistent calcified aneurysms in the responsible artery. In the 7 patients with multiple perfusion CMR scans (median follow-up 47 months), 3 patients developed new ischaemia. Conclusions Long-term surveillance of coronary arteries in adult patients with a childhood history of Kawasaki disease is crucial in the early identification and management of complications. We show that stress perfusion CMR is a useful radiation-free technique for the long-term follow-up of these young patients and is able to identify the development of new ischaemia. Coronary MRA has good agreement in the identification of aneurysms when compared to CTCA. Little is reported in the literature regarding the use of a comprehensive CMR assessment in the follow-up of adult patients with Kawasaki disease and further studies are needed to validate this approach. Funding Acknowledgement Type of funding source: None

Non-contrast coronary magnetic resonance angiography: current frontiers and future horizons

Coronary magnetic resonance angiography (coronary MRA) is advantageous in its ability to assess coronary artery morphology and function without ionizing radiation or contrast media. However, technical limitations including reduced spatial resolution, long acquisition times, and low signal-to-noise ratios prevent it from clinical routine utilization. Nonetheless, each of these limitations can be specifically addressed by a combination of novel technologies including super-resolution imaging, compressed sensing, and deep-learning reconstruction. In this paper, we first review the current clinical use and motivations for non-contrast coronary MRA, discuss currently available coronary MRA techniques, and highlight current technical developments that hold unique potential to optimize coronary MRA image acquisition and post-processing. In the final section, we examine the various research-based coronary MRA methods and metrics that can be leveraged to assess coronary stenosis severity, physiological function, and atherosclerotic plaque characterization. We specifically discuss how such technologies may contribute to the clinical translation of coronary MRA into a robust modality for routine clinical use.