Prognostic value of stress perfusion cardiac magnetic resonance imaging in Kawasaki disease with coronary artery aneurysms: A 10-year retrospective cohort study

BACKGROUND: Kawasaki disease (KD) with coronary artery aneurysms (CAA) places patients at risk for myocardial ischemia and major cardiac events (MCE). While stress perfusion cardiac magnetic resonance imaging (spCMR) is used for surveillance, its prognostic value has not been established. METHODS: We conducted a retrospective cohort study of KD patients (AHA risk levels 3-5) who underwent clinically indicated vasodilator spCMR at a tertiary pediatric center between October 2014 and December 2024. We evaluated inducible perfusion defects, late gadolinium enhancement (LGE), ventricular function, and MCE (myocardial infarction, ventricular dysfunction, arrhythmia, revascularization, transplant, or death). We performed Cox regression and Kaplan-Meier analyses to evaluate risk factors associated with MCE. RESULTS: About 62 patients underwent 107 spCMR examinations. Over a median follow-up of 8.6 years (IQR 5.9-12.1) from KD diagnosis, 18 patients (29.0%) experienced an MCE, all of whom were AHA risk level 5. Nine patients developed MCEs after their first spCMR, and inducible perfusion defects on that initial study were associated with higher risk of subsequent events (HR 4.2, 95% CI 1.1-15.6; p=0.03). Among the 44 AHA risk level 5 patients, inducible perfusion defects occurred in 13 (29.5%), who had a higher incidence of subsequent MCE (44.4% vs. 14.3%, p = 0.045); among those with both significant luminal narrowing and positive spCMR, 64% developed MCE. Serial spCMR identified new inducible defects in patients who later experienced MCE. In six patients, post-operative spCMR helped assess revascularization adequacy and return-to-activity decisions. CONCLUSIONS: In KD patients with CAA, inducible perfusion defects on spCMR were associated with increased MCE risk, whereas a normal spCMR in AHA risk levels 3-4 was reassuring. Serial spCMR identified evolving ischemia, guided revascularization decisions, and informed post-intervention management. These findings support the incorporating spCMR into longitudinal surveillance pathway for high-risk KD patients.