introduction: Children with coronary artery aneurysms (CAA) following Kawasaki disease (KD) are at risk of luminal narrowing and subsequent ischemia. Stress testing/imaging is recommended for high-risk patients to monitor for arrhythmias, ST-T segment changes or abnormalities, but multicenter data is limited.

Methods: Results from stress tests conducted at18 sites participating in the International Kawasaki Disease Registry (IKDR) were reviewed. Logistic regression was used to identify factors associated with abnormal stress responses in the tested children.

Results: A total of 408 stress tests in 133 patients were available for analysis, the mean interval between testing was 18 months. Tests were obtained for routine surveillance in 46 (11%), clinical concerns in 336 (83%), imaging concerns in 15 (4%), and other reasons in 6 (1%). Most tests were exercise stress echocardiography combined with cardiopulmonary exercise tests (320, 76%), followed by cardiopulmonary exercise stress tests with ECG only (74, 18%), dobutamine stress echocardiography (19, 5%), stress perfusion MRI (4, 1%) and nuclear medicine myocardial perfusion scans (3, 1%). Abnormalities were found on 56 tests (14%) in 29 patients and included arrhythmia (18, 32%), chest pain (2, 4%), ST-T segment anomaly changes (33, 59%), and wall motion abnormalities (8, 14%). The average age at first abnormal test was 11.5±3.5 years; four patients were later diagnosed with clinically important coronary artery stenosis, and the majority (16/29, 55%) were prescribed beta blockers. Factors associated with stress test anomalies included higher maximum CAA z-score (average z-score 20.6 vs. 13.5, p=0.03) and multiple acute factors generally associated with greater CAA involvement. Higher number of branches with giant CAAs (1.6 vs. 0.9 branches, p=0.02), presence of multiple, complex or beaded CAA (RCA 52% vs. 26%, p=0.02; LAD 69% vs. 35%, p<0.001), longer CAA length in the LAD (7.9mm vs. 5.2mm, p=0.01) were also associated with stress test abnormalities.

Conclusions: Few patients in this multicenter registry underwent stress testing for routine surveillance, suggesting that it may be underutilized. Stress test for high-risk patients with KD often uncovers anomalies but our data shows inconsistencies regarding the importance and management of those abnormalities.