Overview of U.S. COVID-19 vaccine safety surveillance systems.

The U.S. COVID-19 vaccination program, which commenced in December 2020, has been instrumental in preventing morbidity and mortality from COVID-19 disease. Safety monitoring has been an essential component of the program. The federal government undertook a comprehensive and coordinated approach to implement complementary safety monitoring systems and to communicate findings in a timely and transparent way to healthcare providers, policymakers, and the public. Monitoring involved both well-established and newly developed systems that relied on both spontaneous (passive) and active surveillance methods. Clinical consultation for individual cases of adverse events following vaccination was performed, and monitoring of special populations, such as pregnant persons, was conducted. This report describes the U.S. government's COVID-19 vaccine safety monitoring systems and programs used by the Centers for Disease Control and Prevention, the U.S. Food and Drug Administration, the Department of Defense, the Department of Veterans Affairs, and the Indian Health Service. Using the adverse event of myocarditis following mRNA COVID-19 vaccination as a model, we demonstrate how the multiple, complementary monitoring systems worked to rapidly detect, assess, and verify a vaccine safety signal. In addition, longer-term follow-up was conducted to evaluate the recovery status of myocarditis cases following vaccination. Finally, the process for timely and transparent communication and dissemination of COVID-19 vaccine safety data is described, highlighting the responsiveness and robustness of the U.S. vaccine safety monitoring infrastructure during the national COVID-19 vaccination program.

Trends in mortality risk of patients with congenital heart disease during the COVID-19 pandemic.

BACKGROUND: Cardiovascular conditions are considered risk factors for poor outcomes associated with COVID-19. However, the effect of the COVID-19 pandemic on the mortality of patients with congenital heart disease (CHD) is unclear. Our study aims to examine the trends in mortality risk of CHD patients during the COVID-19 pandemic. METHODS: This is a retrospective cohort study from the Pediatric Cardiac Care Consortium, a US-based registry of interventions for CHD. We included patients having US residence and direct identifiers; death events were captured by matching with the National Death Index. The observation window (2017-2022) was divided into pre-COVID-19 and COVID-19 era defined around the national onset of COVID-19 disease in 2020. Stratified Cox model was used to assess all-cause mortality between the pre- and the COVID-19 era. RESULTS: Among 45,130 patients with CHD (median age in 2017: 23.3 years, IQR: 19.0-28.4), 503 deaths occurred during the pandemic with 44 deaths (8.7%) attributed to COVID-19 (COVID-19 mortality rate of 0.09%). The overall risk of death for patients with all types of CHD during the pandemic was significantly higher compared to the pre-COVID-19 era (aHR 1.28, 95%CI: 1.08-1.53), with a differential trend towards increased risk in patients with two-ventricle (aHR 1.44, 95% CI: 1.19-1.76) vs unchanged risk for those with single ventricle CHD (aHR = 0.83, 95% CI: 0.57-1.21). Adjusted subgroup analysis revealed a higher risk of death during the pandemic for CHD patients with male and chromosomal abnormalities. The excess deaths during the pandemic were attributed to COVID-19 itself rather than CHD or cardiovascular conditions. CONCLUSION: In this large CHD cohort study, there was a higher risk of death among CHD patients with male and chromosomal abnormalities. A differential trend towards higher risk for those with two vs. unchanged risk for single ventricle CHD was presented. The excess mortality was attributed to the COVID-19 itself and not to conditions potentially related to deferral of care. These results justify targeted protective measures towards the CHD population and may provide guidance for public health and medical care response in future epidemics.

Treatments and Severe Outcomes for Patients Diagnosed With MIS-C at Four Children's Hospitals in the United States, March 16, 2020-March 10, 2021.

BACKGROUND: Clinical management of multisystem inflammatory syndrome in children (MIS-C) has varied over time and by medical institution. METHODS: Data on patients with MIS-C were collected from 4 children's hospitals between March 16, 2020 and March 10, 2021. Relationships between MIS-C treatments and patient demographics, clinical characteristics, and outcomes were described. Propensity score matching was utilized to assess the relative risk of outcomes dependent on early treatment with intravenous immunoglobulin (IVIG) or low-dose steroids, controlling for potential confounding variables. RESULTS: Of 233 patients diagnosed with MIS-C, the most commonly administered treatments were steroids (88.4%), aspirin (81.1%), IVIG (77.7%) and anticoagulants (71.2%). Compared with those patients without respiratory features, patients with respiratory features were less likely to receive IVIG and steroids on the same day (combination treatment) (44.1%). Controlling for confounding variables, patients receiving IVIG within 1 day of hospitalization were less likely to have hospital length of stay ≥8 days (RR = 0.53, 95% CI: 0.31-0.88). Patients receiving low-dose steroids within 1 day of hospitalization were less likely to develop ventricular dysfunction (RR = 0.45, 95% CI: 0.26-0.77), have increasingly elevated troponin levels (RR = 0.55, 95% CI: 0.40-0.75) or have hospital length of stay ≥8 days (RR = 0.46, 95% CI: 0.29-0.74). CONCLUSION: Treatments for MIS-C differed by hospital, patient characteristics and illness severity. When IVIG and low-dose steroids were administered in combination or low-dose steroids were administered alone within 1 day of hospitalization, the risk of subsequent severe outcomes was decreased.

COVID Vaccination as a Strategy for Cardiovascular Disease Prevention.

PURPOSE OF REVIEW: Cardiovascular (CV) disease is a known complication of SARS-CoV-2 infection. A clear benefit of COVID-19 vaccination is a reduction mortality; however, COVID-19 vaccination may also prevent cardiovascular disease (CVD). We aim to describe CV pathology associated with SARS-CoV-2 infection and describe how COVID-19 vaccination is a strategy for CVD prevention. RECENT FINDINGS: The risks and benefits of COVID-19 vaccination have been widely studied. Analysis of individuals with and without pre-existing CVD has shown that COVID-19 vaccination can prevent morbidity associated with SARS-CoV-2 infection and reduce mortality. COVID-19 vaccination is effective in preventing myocardial infarction, cerebrovascular events, myopericarditis, and long COVID, all associated with CVD risk factors. Vaccination reduces mortality in patients with pre-existing CVD. Further study investigating ideal vaccination schedules for individuals with CVD should be undertaken to protect this vulnerable group and address new risks from variants of concern.

Distinguishing Incomplete Kawasaki and Nonsevere Multisystem Inflammatory Syndrome in Children.

OBJECTIVES: Characterizing inflammatory syndromes during the coronavirus disease 2019 pandemic was complicated by recognition of multisystem inflammatory syndrome in children (MIS-C), contemporaneous with episodes of Kawasaki disease. We hypothesized a substantial overlap between the 2 and assessed the performance of an MIS-C likelihood score in differentiating inpatients with nonsevere MIS-C from prepandemic incomplete Kawasaki disease (iKD) without coronary involvement. METHODS: A retrospective review of inpatient records was conducted; the nonsevere MIS-C cohort (March 2020-February 2021) met the 2023 definition for MIS-C; the iKD cohort (January 2018-January 2019) met the American Heart Association criteria for iKD without coronary involvement. We applied the likelihood score to both cohorts. We estimated the percent of children with iKD who could have met the clinical criteria of the MIS-C, had they presented in 2023. RESULTS: The 68 children in the nonsevere MIS-C cohort were older (8 vs 4 years, P < .001) than the 28 children in the iKD cohort. Those in the nonsevere MIS-C cohort had higher rates of thrombocytopenia (P < .001) and lymphopenia (P = .021); those in the iKD cohort had higher rates of pyuria (P < .001). Twenty-four (86%) children in the iKD cohort met the 2023 MIS-C definition. The scoring system correctly predicted 71% to 74% children with their respective clinical diagnoses. CONCLUSIONS: Though there was considerable clinical overlap, thrombocytopenia, lymphopenia, and the absence of pyuria were the most helpful parameters to distinguish children with nonsevere MIS-C from those with iKD.

Neighborhood social deprivation and healthcare utilization, disability, and comorbidities among young adults with congenital heart defects: Congenital heart survey to recognize outcomes, needs, and well-being 2016-2019.

BACKGROUND: Research on the association between neighborhood social deprivation and health among adults with congenital heart defects (CHD) is sparse. METHODS: We evaluated the associations between neighborhood social deprivation and health care utilization, disability, and comorbidities using the population-based 2016-2019 Congenital Heart Survey To Recognize Outcomes, Needs, and well-beinG (CH STRONG) of young adults. Participants were identified from active birth defect surveillance systems in three U.S. sites and born with CHD between 1980 and 1997. We linked census tract-level 2017 American Community Survey information on median household income, percent of ≥25-year-old with greater than a high school degree, percent of ≥16-year-olds who are unemployed, and percent of families with children <18 years old living in poverty to survey data and used these variables to calculate a summary neighborhood social deprivation z-score, divided into tertiles. Adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) derived from a log-linear regression model with a Poisson distribution estimated the association between tertile of neighborhood social deprivation and healthcare utilization in previous year (no encounters, 1 and ≥2 emergency room [ER] visits, and hospital admission), ≥1 disability, and ≥1 comorbidities. We accounted for age, place of birth, sex at birth, presence of chromosomal anomalies, and CHD severity in all models, and, additionally educational attainment and work status in all models except disability. RESULTS: Of the 1435 adults with CHD, 43.8% were 19-24 years old, 54.4% were female, 69.8% were non-Hispanic White, and 33.7% had a severe CHD. Compared to the least deprived tertile, respondents in the most deprived tertile were more likely to have no healthcare visit (aPR: 1.5 [95% CI: 1.1, 2.1]), ≥2 ER visits (1.6 [1.1, 2.3]), or hospitalization (1.6 [1.1, 2.3]) in the previous 12 months, a disability (1.2 [1.0, 1.5]), and ≥1 cardiac comorbidities (1.8 [1.2, 2.7]). CONCLUSIONS: Neighborhood social deprivation may be a useful metric to identify patients needing additional resources and referrals.

Survival From Birth Until Young Adulthood Among Individuals With Congenital Heart Defects: CH STRONG.

BACKGROUND: Limited population-based information is available on long-term survival of US individuals with congenital heart defects (CHDs). Therefore, we assessed patterns in survival from birth until young adulthood (ie, 35 years of age) and associated factors among a population-based sample of US individuals with CHDs. METHODS: Individuals born between 1980 and 1997 with CHDs identified in 3 US birth defect surveillance systems were linked to death records through 2015 to identify those deceased and the year of their death. Kaplan-Meier survival curves, adjusted risk ratios (aRRs) for infant mortality (ie, death during the first year of life), and Cox proportional hazard ratios for survival after the first year of life (aHRs) were used to estimate the probability of survival and associated factors. Standardized mortality ratios compared infant mortality, >1-year mortality, >10-year mortality, and >20-year mortality among individuals with CHDs with general population estimates. RESULTS: Among 11 695 individuals with CHDs, the probability of survival to 35 years of age was 81.4% overall, 86.5% among those without co-occurring noncardiac anomalies, and 92.8% among those who survived the first year of life. Characteristics associated with both infant mortality and reduced survival after the first year of life, respectively, included severe CHDs (aRR=4.08; aHR=3.18), genetic syndromes (aRR=1.83; aHR=3.06) or other noncardiac anomalies (aRR=1.54; aHR=2.53), low birth weight (aRR=1.70; aHR=1.29), and Hispanic (aRR=1.27; aHR=1.42) or non-Hispanic Black (aRR=1.43; aHR=1.80) maternal race and ethnicity. Individuals with CHDs had higher infant mortality (standardized mortality ratio=10.17), >1-year mortality (standardized mortality ratio=3.29), and >10-year and >20-year mortality (both standardized mortality ratios ≈1.5) than the general population; however, after excluding those with noncardiac anomalies, >1-year mortality for those with nonsevere CHDs and >10-year and >20-year mortality for those with any CHD were similar to the general population. CONCLUSIONS: Eight in 10 individuals with CHDs born between1980 and 1997 survived to 35 years of age, with disparities by CHD severity, noncardiac anomalies, birth weight, and maternal race and ethnicity. Among individuals without noncardiac anomalies, those with nonsevere CHDs experienced similar mortality between 1 and 35 years of age as in the general population, and those with any CHD experienced similar mortality between 10 and 35 years of age as in the general population.

Cardiology Care and Loss to Follow-Up Among Adults With Congenital Heart Defects in CH STRONG.

Many of the estimated 1.4 million adults with congenital heart defects (CHDs) in the United States are lost to follow-up (LTF) despite recommendations for ongoing cardiology care. Using 2016 to 2019 CH STRONG (Congenital Heart Survey To Recognize Outcomes, Needs, and well-beinG) data, we describe cardiac care among community-based adults with CHD, born in 1980 to 1997, identified through state birth defects registries. Our estimates of LTF were standardized to the CH STRONG eligible population and likely more generalizable to adults with CHD than clinic-based data. Half of our sample were LTF and more than 45% had not received cardiology care in over 5 years. Of those who received care, only 1 in 3 saw an adult CHD physician at their last encounter. Not knowing they needed to see a cardiologist, being told they no longer needed cardiology care, and feeling "well" were the top reasons for LTF, and only half of respondents report doctors discussing the need for cardiac follow-up.

Narrowing the Survival Gap: Trends in Survival of Individuals with Down Syndrome with and without Congenital Heart Defects Born 1979 to 2018.

OBJECTIVE: To evaluate the hypothesis that childhood survival for individuals with Down syndrome (DS) and congenital heart defects (CHDs) has improved in recent years, approaching the survival of those with DS without CHDs. STUDY DESIGN: Individuals with DS born from 1979 to 2018 were identified through the Metropolitan Atlanta Congenital Defects Program, a population-based birth defects surveillance system administered by the Centers for Disease Control and Prevention. Survival analysis was performed to evaluate predictors of mortality for those with DS. RESULTS: The cohort included 1671 individuals with DS; 764 had associated CHDs. The 5-year survival in those with DS with CHD improved steadily among individuals born in the 1980s through the 2010s (from 85% to 93%; P = .01), but remained stable (96% to 95%; P = .97) in those with DS without CHDs. The presence of a CHD was not associated with mortality through 5 years of age for those born 2010 or later (hazard ratio, 2.63; 95% CI, 0.95-8.37). In multivariable analyses, atrioventricular septal defects were associated with early (<1 year) and late (>5 year) mortality, whereas ventricular septal defects were associated with intermediate (1-5 years) mortality and atrial septal defects with late mortality, when adjusting for other risk factors. CONCLUSIONS: The gap in 5-year survival between children with DS with and without CHDs has improved over the last 4 decades. Survival after 5 years remains lower for those with CHDs, although longer follow-up is needed to determine if this difference lessens for those born in the more recent years.

Cardiac Magnetic Resonance Findings of Coronavirus Disease 2019 (COVID-19) Vaccine-Associated Myopericarditis at Intermediate Follow-Up: A Comparison with Classic Myocarditis.

OBJECTIVE: To report intermediate cardiac magnetic resonance (CMR) findings of coronavirus disease 2019 (COVID-19) vaccine-associated myopericarditis (C-VAM) and compare with classic myocarditis. STUDY DESIGN: Retrospective cohort study including children diagnosed with C-VAM from May 2021 through December 2021 with early and intermediate CMR. Patients with classic myocarditis from January 2015 through December 2021 and intermediate CMR were included for comparison. RESULTS: There were 8 patients with C-VAM and 20 with classic myocarditis. Among those with C-VAM, CMR performed at a median 3 days (IQR 3, 7) revealed 2 of 8 patients with left ventricular ejection fraction <55%, 7 of 7 patients receiving contrast with late gadolinium enhancement (LGE), and 5 of 8 patients with elevated native T1 values. Borderline T2 values suggestive of myocardial edema were present in 6 of 8 patients. Follow-up CMRs performed at a median 107 days (IQR 97, 177) showed normal ventricular systolic function, T1, and T2 values; 3 of 7 patients had LGE. At intermediate follow-up, patients with C-VAM had fewer myocardial segments with LGE than patients with classic myocarditis (4/119 vs 42/340, P = .004). Patients with C-VAM also had a lower frequency of LGE (42.9 vs 75.0%) and lower percentage of left ventricular ejection fraction <55% compared with classic myocarditis (0.0 vs 30.0%), although these differences were not statistically significant. Five patients with classic myocarditis did not receive an early CMR, leading to some selection bias in study design. CONCLUSIONS: Patients with C-VAM had no evidence of active inflammation or ventricular dysfunction on intermediate CMR, although a minority had persistent LGE. Intermediate findings in C-VAM revealed less LGE burden compared with classic myocarditis.

Reproductive Health Counseling and Concerns Among Women with Congenital Heart Defects With and Without Disabilities.

Background: Women with disabilities are less likely to receive reproductive health counseling than women without disabilities. Yet, little is known about reproductive health counseling and concerns among women with congenital heart defects (CHD) and disabilities. Methods: We used population-based survey data from 778 women aged 19 to 38 years with CHD to examine contraceptive and pregnancy counseling and pregnancy concerns and experiences by disability status, based on six validated questions on vision, hearing, mobility, cognition, self-care, and living independently. Multivariable Poisson regression was used to examine adjusted prevalence ratios between disability status and each outcome, adjusted for CHD severity, age, race/ethnicity, place of birth (Arkansas, Arizona, Georgia), and insurance type. Results: Women with disabilities (n = 323) were 1.4 and 2.3 times more likely than women without disabilities (n = 455) to receive clinician counseling on safe contraceptive methods and avoiding pregnancy because of their CHD. Women with CHD and disabilities, compared to those without disabilities, were more likely to be concerned about their ability to have children (aPR = 1.2) and to have delayed or avoided pregnancy (aPR = 2.2); they were less likely to have ever been pregnant (aPR = 0.7). Associations differed slightly across specific disability types. All associations remained after excluding 71 women with chromosomal anomalies. Conclusion: Among women with CHD, reproductive counseling, concerns, and experiences differ by disability status.

Cardiac complications in children with acute COVID-19 vs multisystem inflammatory syndrome in children (MIS-C).

BACKGROUND: Cardiac involvement can lead to significant morbidity in children with acute COVID-19 or multisystem inflammatory syndrome in children (MIS-C). However, the presentation and outcomes of cardiac involvement may differ among these 2 conditions. We aimed to compare the frequency and extent of cardiac involvement among children admitted with acute COVID-19 vs those with MIS-C. METHODS: We conducted a cross sectional study of patients admitted to our hospital from March 2020 to August 2021 with symptomatic acute COVID-19 or MIS-C. Cardiac involvement was defined by presence of 1 or more of the following: elevated troponin, elevated brain natriuretic peptide, reduced left ventricular ejection fraction on echocardiogram, coronary dilation on echocardiogram, or abnormal electrocardiogram reading. RESULTS: Among 346 acute COVID-19 patients with median age of 8.9 years and 304 MIS-C patients with median age of 9.1 years, cardiac involvement was present in 33 acute COVID-19 patients (9.5%) and 253 MIS-C patients (83.2%). The most common cardiac abnormality was abnormal electrocardiogram in acute COVID-19 patients (7.5%) and elevated troponin in MIS-C patients (67.8%). Among acute COVID-19 patients, obesity was significantly associated with cardiac involvement. Among MIS-C patients, non-Hispanic Black race/ethnicity was significantly associated with cardiac involvement. CONCLUSIONS: Cardiac involvement is much more common in children with MIS-C than in those with acute COVID-19. These results reinforce our standardized practice of performing full cardiac evaluations and follow-up in all patients with MIS-C but only in acute COVID-19 patients with signs or symptoms of cardiac involvement.

Six-month cardiac outcomes in children with multisystem inflammatory syndrome in children.

BACKGROUND: Multisystem inflammatory syndrome in children is a rare, post-infectious complication of SARS-CoV-2 infection in children. We aimed to assess the long-term sequelae, particularly cardiac, in a large, diverse population. METHODS: We performed a retrospective cohort study of all children (aged 0-20 years, n = 304) admitted to a tertiary care centre with a diagnosis of multisystem inflammatory syndrome in children from March 1, 2020 to August 31, 2021 and had at least one follow-up visit through December 31, 2021. Data were collected at hospitalisation, 2 weeks, 6 weeks, 3 months, and 1 year after diagnosis, where applicable. Cardiovascular outcomes included left ventricular ejection fraction, presence or absence of pericardial effusion, coronary artery abnormalities, and abnormal electrocardiogram findings. RESULTS: Population was median age 9 years (IQR 5-12), 62.2% male, 61.8% African American (AA), and 15.8% Hispanic. Hospitalisation findings included abnormal echocardiogram 57.2%, mean worst recorded left ventricular ejection fraction 52.4% ± 12.4%, non-trivial pericardial effusion 13.4%, coronary artery abnormalities 10.6%, and abnormal ECG 19.6%. During follow-up, abnormal echocardiogram significantly decreased to 6.0% at 2 weeks and 4.7% at 6 weeks. Mean left ventricular ejection fraction significantly increased to 65.4% ± 5.6% at 2 weeks and stabilised. Pericardial effusion significantly decreased to 3.2% at 2 weeks and stabilised. Coronary artery abnormalities significantly decreased to 2.0% and abnormal electrocardiograms significantly decreased to 6.4% at 2 weeks and stabilised. CONCLUSION: Children with multisystem inflammatory syndrome in children have significant echocardiographic abnormalities during the acute presentation, but these findings typically improve within weeks. However, a small subset of patients may have persistent coronary abnormalities.

Racial and ethnic disparities in socio-economic status, access to care, and healthcare utilisation among children with heart conditions, National Survey of Children's Health 2016-2019.

Among children with and without heart conditions of different race/ethnicities, upstream social determinants of health, such as socio-economic status, access to care, and healthcare utilisation, may vary. Using caregiver-reported data from the 2016-19 National Survey of Children's Health, we calculated the prevalence of caregiver employment and education, child's health insurance, usual place of medical care in the past 12 months, problems paying for child's care, ≥2 emergency room visits, and unmet healthcare needs by heart condition status and race/ethnicity (Hispanic, non-Hispanic Black, and non-Hispanic White). For each outcome, we used multivariable logistic regression to generate adjusted prevalence ratios controlling for child's age and sex. Of 2632 children with heart conditions and 104,841 without, 65.4% and 58.0% were non-Hispanic White and 52.0% and 51.1% were male, respectively. Children with heart conditions, compared to those without, were 1.7-2.6 times more likely to have problems paying for healthcare, have ≥2 emergency room visits, and have unmet healthcare needs. Hispanic and non-Hispanic Black children with heart conditions, compared to non-Hispanic White, were 1.5-3.2 times as likely to have caregivers employed <50 weeks in the past year and caregivers with ≤ high school education, public or no health insurance, no usual place of care, and ≥2 emergency room visits. Children with heart conditions, compared to those without, may have greater healthcare needs that more commonly go unmet. Among children with heart conditions, Hispanic and non-Hispanic Black children may experience lower socio-economic status and greater barriers to healthcare than non-Hispanic White children.

Multiple MIS-C Readmissions and Giant Coronary Aneurysm After COVID-19 Illness and Vaccination: A Case Report.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) rarely involves delayed giant coronary aneurysms, multiple readmissions or occurrence after COVID-19 vaccination. METHODS: We describe a child with all 3 of these unusual features. We discuss his clinical presentation, medical management, review of the current literature and CDC guidance recommendations regarding further vaccinations. RESULTS: A 5-year-old boy had onset of MIS-C symptoms 55 days after COVID-19 illness and 15 days after receiving his first BNT162b2 COVID-19 vaccination. He was admitted 3 times for MIS-C, and twice after his steroid dose was tapered. On his initial admission, he was given intravenous immunoglobulin and steroids. During his second admission, new, moderate coronary dilation was noted, and he was treated with intravenous immunoglobulin and steroids. At his last admission, worsening coronary dilation was noted, and he was treated with infliximab and steroids. During follow-up, he had improvement in his coronary artery dilatation. However, his inflammatory markers increased after steroid wean, and his steroid taper was further extended, after which time his inflammatory markers improved. This is the only such reported case of a patient who was admitted 3 times for MIS-C complications after COVID-19 vaccination. CONCLUSION: MIS-C rarely involves delayed giant coronary aneurysms, multiple readmissions, or occurrence after COVID-19 vaccination. Whether our patient's COVID-19 vaccine 6 weeks after COVID-19 illness contributed to his MIS-C is unknown. After consultation with the CDC-funded Clinical Immunization Safety Assessment Project, the patient's care team decided against further COVID-19 vaccination until at least 3 months post normalization of inflammatory markers.

Reproductive Health of Women with Congenital Heart Defects.

This report provides an overview of the unique reproductive health issues facing women with congenital heart defects (CHDs) and of the clinical care and professional guidelines on contraception, preconception care, and pregnancy for this population. It describes Centers for Disease Control and Prevention (CDC) activities related to surveillance of reproductive health issues among females with CHDs. It also describes CDC's work bringing awareness to physicians who provide care to adolescents and women with CHDs, including obstetrician/gynecologists, about the need for lifelong cardiology care for their patients with CHDs.

Examination of Adverse Reactions After COVID-19 Vaccination Among Patients With a History of Multisystem Inflammatory Syndrome in Children.

Importance: Data are limited regarding adverse reactions after COVID-19 vaccination in patients with a history of multisystem inflammatory syndrome in children (MIS-C). The lack of vaccine safety data in this unique population may cause hesitancy and concern for many families and health care professionals. Objective: To describe adverse reactions following COVID-19 vaccination in patients with a history of MIS-C. Design, Setting, and Participants: In this multicenter cross-sectional study including 22 North American centers participating in a National Heart, Lung, and Blood Institute, National Institutes of Health-sponsored study, Long-Term Outcomes After the Multisystem Inflammatory Syndrome in Children (MUSIC), patients with a prior diagnosis of MIS-C who were eligible for COVID-19 vaccination (age ≥5 years; ≥90 days after MIS-C diagnosis) were surveyed between December 13, 2021, and February 18, 2022, regarding COVID-19 vaccination status and adverse reactions. Exposures: COVID-19 vaccination after MIS-C diagnosis. Main Outcomes and Measures: The main outcome was adverse reactions following COVID-19 vaccination. Comparisons were made using the Wilcoxon rank sum test for continuous variables and the χ2 or Fisher exact test for categorical variables. Results: Of 385 vaccine-eligible patients who were surveyed, 185 (48.1%) received at least 1 vaccine dose; 136 of the vaccinated patients (73.5%) were male, and the median age was 12.2 years (IQR, 9.5-14.7 years). Among vaccinated patients, 1 (0.5%) identified as American Indian/Alaska Native, non-Hispanic; 9 (4.9%) as Asian, non-Hispanic; 45 (24.3%) as Black, non-Hispanic; 59 (31.9%) as Hispanic or Latino; 53 (28.6%) as White, non-Hispanic; 2 (1.1%) as multiracial, non-Hispanic; and 2 (1.1%) as other, non-Hispanic; 14 (7.6%) had unknown or undeclared race and ethnicity. The median time from MIS-C diagnosis to first vaccine dose was 9.0 months (IQR, 5.1-11.9 months); 31 patients (16.8%) received 1 dose, 142 (76.8%) received 2 doses, and 12 (6.5%) received 3 doses. Almost all patients received the BNT162b2 vaccine (347 of 351 vaccine doses [98.9%]). Minor adverse reactions were observed in 90 patients (48.6%) and were most often arm soreness (62 patients [33.5%]) and/or fatigue (32 [17.3%]). In 32 patients (17.3%), adverse reactions were treated with medications, most commonly acetaminophen (21 patients [11.4%]) or ibuprofen (11 [5.9%]). Four patients (2.2%) sought medical evaluation, but none required testing or hospitalization. There were no patients with any serious adverse events, including myocarditis or recurrence of MIS-C. Conclusions and Relevance: In this cross-sectional study of patients with a history of MIS-C, no serious adverse events were reported after COVID-19 vaccination. These findings suggest that the safety profile of COVID-19 vaccination administered at least 90 days following MIS-C diagnosis appears to be similar to that in the general population.

Exercise testing in patients with multisystem inflammatory syndrome in children-related myocarditis versus idiopathic or viral myocarditis.

BACKGROUND: While most children with multisystem inflammatory syndrome in children have rapid recovery of cardiac dysfunction, little is known about the long-term outcomes regarding exercise capacity. We aimed to compare the exercise capacity among patients with multisystem inflammatory syndrome in children versus viral/idiopathic myocarditis at 3-6 months after initial diagnosis. METHODS: We performed a retrospective cohort study among patients with multisystem inflammatory syndrome in children in June 2020 to May 2021 and patients with viral/idiopathic myocarditis in August 2014 to January 2020. Data from cardiopulmonary exercise test as well as echocardiographic and laboratory data were obtained. Inclusion criteria included diagnosis of multisystem inflammatory syndrome in children or viral/idiopathic myocarditis, exercise test performed within 3-6 months of hospital discharge, and maximal effort on cardiopulmonary exercise test as determined by respiratory exchange ratio >1.10. RESULTS: Thirty-one patients with multisystem inflammatory syndrome in children and 25 with viral/idiopathic myocarditis were included. The mean percent predicted peak VO2 was 90.84% for multisystem inflammatory syndrome in children patients and 91.08% for those with viral/idiopathic myocarditis (p-value 0.955). There were no statistically significant differences between the groups with regard to percent predicted maximal heart rate, metabolic equivalents, percent predicted peak VO2, percent predicted anerobic threshold, or percent predicted O2 pulse. There was a statistically significant correlation between lowest ejection fraction during hospitalisation and peak VO2 among viral/idiopathic myocarditis patients (r: 0.62, p-value 0.01) but not multisystem inflammatory syndrome in children patients (r: 0.1, p-value 0.6). CONCLUSIONS: Patients with multisystem inflammatory syndrome in children and viral myocarditis appear to, on average, have normal exercise capacity around 3-6 months following hospital discharge. For patients with viral/idiopathic myocarditis, those with worse ejection fraction during hospitalisation had lower peak VO2 on cardiopulmonary exercise test.