Design and rationale of the MIGHTEE study: Motivational interviewing and group heart transplant exercise and education.

Background: Many pediatric heart transplant (HT) recipients have decreased physical activity, which worsens their cardiovascular risk profile, contributes to long-term morbidity and mortality, and is associated with lower quality of life (QOL). While participation in a regular exercise program improves the cardiovascular health of pediatric HT recipients, there are limited data on how to best implement exercise-based interventions that are accessible, effective, and sustainable. Methods: This manuscript describes the design, rationale, and baseline cohort characteristics of the Motivational Interviewing and Group Heart Transplant Exercise and Education (MIGHTEE) intervention, a structured virtual group exercise program developed with input from pediatric HT recipients and their families. Results: Over 24 months, 65 HT recipients were screened, and 44 recipients were determined to be eligible. Of the 23 subjects enrolled in MIGHTEE (52% enrollment rate), the majority were male (52%), and 26% self-identified as Black. The mean subject age was 16.1 years (standard deviation [SD] = 2.2), and the mean time from HT was 4.9 years (range = 1-18 years) with 43% having a history of congenital heart disease. All participants completed baseline testing, and wearable device adherence exceeded 80% of monitored days. Conclusions: This manuscript describes the rationale and study design of the MIGHTEE study, which will provide important data regarding the optimal methods for delivering physical activity-related interventions to pediatric HT survivors. This design and rationale paper highlights the feasibility of enrollment and program delivery, with outcomes analyses forthcoming in subsequent reports.