Abstract Background Thromboembolic events related to invasive electrophysiology studies, while rare, can have devastating consequences. Use of systemic anticoagulation for a pediatric or adult‐congenital invasive electrophysiology study is recommended, however there is no established standard of practice in this population. Objective To report on procedural practices for thromboembolism prophylaxis during invasive electrophysiology studies for pediatric patients and adults with congenital heart disease. Methods An anonymous web‐based survey was sent to the members of the Pediatric and Congenital Electrophysiology Society. The survey focused on pre‐procedural, intra‐procedural, and post‐procedural thromboembolism prophylaxis practices during invasive electrophysiology studies. Significant practice variation was defined as <90% concordance among respondents. Results Survey was completed by 73 members; 52 (71%) practicing in the United States, 65 (89%) practicing in an academic institution, and 14 (19%) in an institution that performs more than 200 invasive electrophysiology procedures annually. Responses showed significant variation in practice. Prior to an invasive electrophysiology procedure, 25% discontinue aspirin while 47% discontinue anticoagulants. Heparin is given for all procedures by 32%. When heparin is administered, the first dose is given by 32% after sheaths are placed, 42% after crossing into the systemic atrium, and 26% just prior to systemic‐side ablation. Most target an activated clotting time between 200–300 seconds. Post systemic‐side ablation, 58% do not initiate a heparin infusion. Post‐procedural oral agents were initiated on day of procedure by 34% of respondents and on post‐procedure day 1 by 53%. If treating with aspirin, 74% use low‐dose (3–5 mg/kg or 81 mg daily), and 68% treat for 4–6 weeks. Conclusion There is significant variation in thromboembolism prophylaxis for invasive EP studies among pediatric and congenital electrophysiologists. Further studies are needed to optimize the management of thromboembolism prophylaxis in this population.
Background: The sequelae of COVID-19 vaccine associated myocarditis (C-VAM) are incompletely understood. We sought to characterize the clinical course, myocardial injury, and outcomes in C-VAM.Methods: In this retrospective observational cohort multicenter study across 38 hospitals in the U.S., we compared the clinical and cardiac imaging characteristics in 333 C-VAM patients from April 2021 to November 2022 with those in 100 multisystem inflammatory syndrome in children (MIS-C) patients and explored the risk factors for myocardial injury in C-VAM.Findings: The C-VAM patients were predominantly white (67%) adolescent males (91%, 15·7±2·8 years) with a mild initial clinical course and a lower prevalence of left ventricular dysfunction, in comparison to MIS-C patients (17% vs 68%, p<0·0001). Conversely, acute cardiomyocyte injury as evidenced by myocardial late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging was higher in C-VAM compared to MIS-C (82% vs.16%, p<0·001). The odds of having LGE in C-VAM were 2·74 (95% CI: 1·28, 5·83, p=0·009) times higher for older adolescents (>15 years) compared to younger patients, 3·28 (95% CI: 0·99, 10·6, p=0·052) times higher for males compared to females, and 7·18 (95% CI: 1·05, 49·09, p=0·045) times higher with the first dose and 4·5 times higher (95% CI: 1·23, 16·44, p=0·023) with the second dose compared to the third dose of the mRNA vaccine. There were no cardiac deaths or need for heart transplantation in C-VAM at a median follow-up duration of 178 days (IQR 114-285 days) and LGE decreased in prevalence and severity but remained present in 60% of the patients at follow up.Interpretation: COVID-19 vaccine-associated myocarditis is characterized with a milder initial clinical presentation but higher prevalence of myocardial injury, in contrast to MIS-C. Mid-term clinical outcomes are reassuring but the persistence of LGE warrants continued surveillance in C-VAM. Funding: This study was funded by the U.S Food and Drug Administration, FDA-75F40122C00148. Declaration of Interest: SSJ, LGW, SA, JMS, HCW, JCM, JHS, RSB, VM, XJ, OHF, BF, SB, RCA, SAM, NM, JAS, SS, DV, AKVH, MJC, JK, SH, CM, MDC, MS, LN, JYA, SCU, PR, JKP, JGM, JAV, MPD, MB, PB, PE, KM, KG, MLD, KAA, AK, SBB, ALD, PKM, JS, ALC, JDR, ZP, AC, YS, LG, MA, MJ, JDR, NN, EDD report no competing interests. ASH: Site PI for the CAMP study - NHLBI funded, Site PI for MUSIC – NIH funded, Site PI for PREVAIL, supported by a sub-agreement from the Johns Hopkins University with funds provided by Grant No. R61HD105591 from the Eunice Kennedy Shriver National Institute of Child Health & Human Development and the Office of the Director, National Institute of Health (OD). Scientific advisory board member of OP2 DRUGS ("OP2"), states that no work has been done. ABY: Institution received funds for conducting phase 3 clinical trials for Pfizer mRNA COVID-19 vaccine (C4591007 and C4591048). LEH: Patent US11457889B2, issued: Oct 4, 2022, Patent US2023/0016283A1 Published: Jan 19, 2023. FH: Payment for Expert Testimony in pending court case as an expert witness to discuss the risk of C-VAM. DT and SS: Grant or contract from New England Research Institute for participation in Pediatric Heart Network CAMP Study. MJC: Subject matter expert for CDC CISA program, Consulting fees Longerone Inc.Ethical Approval: nstitutional research ethics boards approved the study at every participating site and waived the requirements for informed written consent.
