The interstage period between the first and second palliation for hypoplastic left heart syndrome (HLHS) is a high-risk period. Recurrent coarctation of the aorta (RCoA) is a common complication with an incidence of approximately 10-20%. Early recognition of RCoA following the Norwood operation may prevent significant interstage morbidity and mortality. Cardiac High Acuity Monitoring Program® (CHAMP) is a mobile home monitoring application enabling caregiver-acquired home physiologic data and videos to be instantly relayed to the clinical team. The aim of this study is to investigate if caregiver-entered data results in earlier identification of patients requiring interventional catheterization for RCoA.

Retrospective home monitoring data was extracted from 5 high-volume CHAMP-affiliated centers, defined as contributing >20 patients to the registry, between 2014-2021 after IRB approval. In the 14-days prior to hospital readmission for RCoA intervention, caregiver-recorded heart rate (HR), oxygen saturation (SpO2), weight, videos, and ‘red flags’ (qualitative signs such as feeding difficulties, increased work of breathing, etc.) were collected. Metrics were independently fit to a logistic model, adjusting for sex, shunt type, ICU discharge day-of-life, patient race, and readmission age. A 10,000-iteration bootstrap estimated the directionality and magnitude of associations between each factor and incidence of RCoA catherization during readmission. 

Given the exploratory nature of the work and small sample sizes, all relationships were assessed at 90% confidence. 45 of the 167 patients who underwent cardiac catherization had RCoA interventions. For the 20 patients with multiple readmissions, only data prior to the first was included for analysis. Each patient’s condition in the 7-days prior to readmission was reviewed by measures of adherence (percentage of days of vitals, videos, and weight recordings) with variability and summary statistics of vital signs. In the 7-days prior to readmission, associations with higher odds of catherization included (mean bootstrap coefficient, [90% CI]) increased adherence for vitals (0.336, [0.009-0.697]), weight (0.406, [0.056-0.794]) and video recordings (0.666, [0.322-1.042]); total red-flags (0.354, [0.032-0.708]); standard deviation (0.381, [0.047-0.742]) and range of HR (0.412, [0.070-0.787]); and mean (0.443, [0.101-0.814]) and IQR of SpO2 (0.377, [0.032-0.716]). Positive associations between change in HR measurements and odds of catherization (0.377, [0.032-0.716]) were noted between the 7-days prior to readmission and the week prior. 

Results highlight several notable associations of home monitoring data with catherization during the readmission. Interstage patients with RCoA had increased caregiver-entered home monitoring data, total red flags, and HR and SpO2 changes. Identification of these items by home monitoring teams may be beneficial in clinical decision-making for the evaluation and/or catheterization of these high-risk patients. Additionally, knowledge of a high potential for recurrent coarctation may allow for better counseling of parents prior to clinic appointments where a cardiac catheterization may be discussed.