Design and rationale of the <underline>C</underline>OVID vaccine-<underline>a</underline>ssociated <underline>m</underline>yocarditis/ <underline>p</underline>ericarditis (CAMP) study

Background Minimal data are available on mid- and long-term outcomes following COVID-19 vaccine-associated myocarditis/pericarditis. The COVID Vaccine-Associated Myocarditis /Pericarditis (CAMP) study aims to characterize the mid- and long-term sequelae of myocarditis/pericarditis following administration of any Pfizer-BioNTech COVID-19 vaccine (herein referred to as COMIRNATY (R)). Herein we describe the rationale and design of CAMP. Methods This ongoing and actively enrolling multicenter observational cohort study across 32 North American pediatric cardiac centers will include at least 200 patients < 21 years-old who presented <= 21 days from COMIRNATY (R) vaccination and meet the Centers for Disease Control and Prevention (CDC) case definition of probable or confirmed myocarditis/pericarditis or isolated pericarditis. The comparison cohort will consist of 100 patients < 21 years-old with COVID19 associated myocarditis/pericarditis, including those who meet the contemporaneous CDC case definition of multisystem inflammatory syndrome (MIS-C). The study will collect detailed hospital and follow-up data for up to 5 years following illness onset. Electrocardiograms, echocardiograms, and cardiac magnetic resonance (CMR) examinations will be interpreted in core laboratories. The primary outcomes are 1) composite of left ventricular ejection fraction < 55% by echocardiogram, findings of myocarditis by original or revised Lake Louise criteria on CMR, and/or the presence of high-grade arrhythmias or conduction system disturbances at 6 months after myocarditis/pericarditis onset; 2) complications, such as death, and non-cardiac morbidities; and 3) patient-reported outcomes of global health, functional status, and quality of life. Analyses will include descriptive statistics and regression modeling. Current Status Still enrolling, with 273 participants currently enrolled as of 10/16/2024 (173 vaccine-associated myocarditis/pericarditis, 100 COVID-19-associated myocarditis/pericarditis) Conclusions With long-term follow-up and core laboratories for standardized assessments of cardiac testing, the CAMP study will make important contributions to our understanding of the mid- and long-term cardiac and non-cardiac sequelae of COVID-19 vaccine-associated myocarditis/pericarditis.