Khrongsrattha S.Vijarnsorn C.Santimahakullert K.Hongkan W.Petarwut N.Srivichean A.Thammasate P.Pacharapakornpong T.Kanjanauthai S.Chungsomprasong P.Chanthong P.Durongpisitkul K.Soongswang J.Mahidol University2026-02-062026-02-062026-12-01Scientific Reports Vol.16 No.1 (2026)https://repository.li.mahidol.ac.th/handle/123456789/114485The overlapping features of multisystem inflammatory syndrome in children (MIS-C) and Kawasaki disease (KD) raise concerns regarding midterm cardiovascular sequelae. We conducted a multicenter prospective cohort study to compare midterm outcomes in MIS-C and KD survivors. A total of 122 children (MIS-C, n = 66; KD, n = 56) underwent echocardiographic follow-up 1–3 years post-diagnosis. Outcomes included left ventricular ejection fraction (LVEF), coronary abnormalities, and left ventricular global longitudinal strain (LVGLS). Notably, the median age at diagnosis was higher in MIS-C (5.7 years, IQR 3.0–9.4) than in KD (1.5 years, IQR 1.1–2.8) (P < 0.01). Initial left ventricular dysfunction occurred more frequently in MIS-C (25.8%) than KD (0%) (P < 0.01). By the median follow-up of 1.5 years (IQR 1.1–1.9), all patients who had previously been diagnosed with left ventricular dysfunction had recovered to normal LVEF in both groups. However, one MIS-C patient had persistently abnormal LVGLS, suggesting subclinical impairment. Coronary abnormalities in MIS-C decreased from 30% at baseline to 1.5% at follow-up. In contrast, persistent coronary abnormalities remained in KD, despite preserved cardiac function and LVGLS. At follow-up, coronary abnormalities including coronary ectasia and aneurysm were significantly higher in KD (14.2%) compared with MIS-C (1.5%) (P < 0.01). In conclusion, MIS-C was associated with transient ventricular dysfunction but rare persistent coronary involvement, whereas KD carried a higher burden of midterm coronary abnormalities. Clinical trial registration: TCTR20230414003.MultidisciplinaryArticleSCOPUS10.1038/s41598-025-30867-92-s2.0-1050269477762045232241318810