Population-based study of multisystem inflammatory syndrome associated with COVID-19 found that 36% of children had persistent symptoms.

AIM: Our aim was to describe the outcomes of multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19. METHODS: This national, population-based, longitudinal, multicentre study used Swedish data that were prospectively collected between 1 December 2020 and 31 May 2021. All patients met the World Health Organization criteria for MIS-C. The outcomes 2 and 8 weeks after diagnosis are presented, and follow-up protocols are suggested. RESULTS: We identified 152 cases, and 133 (87%) participated. When followed up 2 weeks after MIS-C was diagnosed, 43% of the 119 patients had abnormal results, including complete blood cell counts, platelet counts, albumin levels, electrocardiograms and echocardiograms. After 8 weeks, 36% of 89 had an abnormal patient history, but clinical findings were uncommon. Echocardiogram results were abnormal in 5% of 67, and the most common complaint was fatigue. Older children and those who received intensive care were more likely to report symptoms and have abnormal cardiac results. CONCLUSION: More than a third (36%) of the patients had persistent symptoms 8 weeks after MIS-C, and 5% had abnormal echocardiograms. Older age and higher levels of initial care appeared to be risk factors. Structured follow-up visits are important after MIS-C.

Diagnostic values of the femoral pulse palpation test.

OBJECTIVES: To calculate diagnostic values of the femoral pulse palpation to detect coarctation of the aorta or other left-sided obstructive heart anomalies in newborn infants. DESIGN: Population-based cohort study. SETTING: Stockholm-Gotland County 2008-2012. PATIENTS: All singleton live-born infants without chromosomal trisomies, at ≥35 gestational weeks, followed-up until 1-2 years of age. MAIN OUTCOME MEASURES: Diagnostic values and ORs for the femoral pulse test and subsequent diagnosis of coarctation of the aorta or left-sided obstructive heart malformation. RESULTS: Among the 118 592 included infants, 432 had weak or absent femoral pulses at the newborn examination. Seventy-eight infants were diagnosed with coarcation of the aorta and 48 with other left-sided obstructive heart malformations. The diagnostic values for the femoral pulse palpation test to detect coarctation of the aorta were: sensitivity: 19.2%, specificity: 99.6, positive predictive value: 3.5% and negative predictive value: 99.9%. For left-sided heart malformations: sensitivity: 8.3%, specificity: 99.6%, positive predictive value: 0.9% and negative predictive value: 100%. Sensitivity for coarctation of the aorta increased from 16.7% when examined at <12 hours of age to 30.0% at ≥96 hours of age. CONCLUSIONS: The femoral pulse test to detect coarctation of the aorta and left-sided heart malformations has limited sensitivity, whereas specificity is high. As many infants with life-threatening cardiac malformations leave the maternity ward undiagnosed, further efforts are necessary to improve the diagnostic yield of the routine newborn examination.