Design and rationale of the COVID vaccine-associated myocarditis/pericarditis (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®). 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® 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 COVID-19 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.