Heart Rate Recovery Following Exercise Testing in Pediatric Patients with Acyanotic Repaired Congenital Heart Disease

Attenuated heart rate recovery (HRR) following peak exercise has been shown to be a predictor of mortality in populations of adults with Fontan palliation, coronary artery disease, heart failure, and heart transplantation. However, few have studied HRR in children and adolescents with congenital heart disease (CHD). This case-control study compared HRR patterns from exercise stress testing in children and adolescents with and without repaired acyanotic CHD (raCHD). Retrospective analysis included patients aged 10-18 years who had exercise testing between 2007 and 2017. The raCHD cohort included patients with Tetralogy of Fallot, transposition of the great arteries, coarctation, truncus arteriosus, atrioventricular septal defect, pulmonary outflow obstruction, aortic stenosis and/or insufficiency, or septal defects. Those in the control cohort were matched for age, sex, BMI, peak METs achieved, and peak heart rate (HR). HR at 1-min intervals throughout the 10-min recovery period and HRR patterns were analyzed. The study included n = 584 individuals (raCHD: n = 146), median age 14 years old, 67.1% male. The cohorts had similar resting and peak HRs. Linear mixed-effects models (LMM) suggested statistically significant cohort-by-time interaction for HR in exercise recovery, with the largest mean difference at minute-6 (2.9 bpm, p = 0.008). When comparing lesion types, LMM found no cohort or cohort-by-time interaction. While minute-6 of exercise recovery was statistically significant, the difference was 2.9 bpm and may not have clinical significance. These results suggest that HRR in pediatric raCHD patients should not vary from their healthy peers, and an attenuated HRR may not be directly attributed to underlying raCHD.