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The aim of this study was to evaluate the accuracy of cardiac magnetic resonance (CMR) in predicting coronary artery (CA) compression during transcatheter pulmonary valve implantation (TPVi).TPVi is a widely available option to treat dysfunctional right ventricle (RV)-to-pulmonary artery (PA) conduits, but CA compression is an absolute contraindication. CMR can evaluate coronary anatomy, but its utility in predicting CA compression is not well established.After Institutional Review Board approval was obtained, all patients at 9 centers with attempted TPVi in RV-PA conduits and recent CMR (≤12 months) were analyzed. A core laboratory reviewed all CMR studies for the shortest orthogonal distance from a CA to the conduit, the shortest distance from a CA to the most stenotic area of the conduit, and subjective assessment of CA compression risk.Among 231 patients, TPVi was successful in 198 (86%); in 24 (10%), balloon testing precluded implantation (documented CA compression or high risk). Distance to the RV-PA conduit ≤2.1 mm (area under the curve [AUC]: 0.70) and distance to most stenotic area ≤13.1 mm (AUC: 0.69) predicted CA compression. Subjective assessment had the highest AUC (0.78), with 96% negative predictive value. Both distances and qualitative assessment remained independently associated with CA compression when controlling for abnormal coronary anatomy or degree of conduit calcification.CMR can help predict the risk for CA compression during TPVi in RV-PA conduits but cannot completely exclude CA compression. CMR may assist in patient selection and counseling families prior to TPVi, although balloon testing remains essential.

Introduction: Transcatheter pulmonary valve implantation (TPVi) is a widely available option to treat right ventricular outflow tract (RVOT) conduits, but coronary artery compression is an absolute contraindication. Cardiac magnetic resonance (CMR) may evaluate coronary anatomy, but its utility in predicting coronary compression is not well established. Hypothesis: CMR prior to TPVi can accurately predict coronary compression risk. Methods: We analyzed all patients with a recent CMR (≤ 12 months) and attempted TPVi in an RVOT conduit at 9 centers from 2007-2016. A core lab reviewed all CMRs for the shortest orthogonal distance from a coronary artery to the conduit, the shortest distance from a coronary artery to the most stenotic area of the conduit, and subjective assessment of coronary compression risk. Receiver operating characteristic curve was used to determine optimal predictive distances. Univariate and independent associations of the distances and qualitative assessment with coronary compression were examined using logistic regression. Results: Of 231 patients (62% male, median age 19.0 years), TPVi was successful in 198 (86%); in 24 (10%) balloon testing (documented coronary compression or high risk) precluded implantation. Distance to the RV to PA conduit ≤ 2.1 mm (area under the curve [AUC] 0.70) and distance to most stenotic area ≤ 13.1 mm (AUC 0.69) predicted coronary compression (Table). Subjective assessment had the highest AUC (0.78), with 96% negative predictive value. Both distances and qualitative assessment remained independently associated with coronary compression when controlling for abnormal coronary anatomy. Conclusions: CMR can predict the risk of coronary compression during TPVi in RVOT conduits but cannot completely exclude the risk of coronary compression. CMR may assist in patient selection and counselling families prior to TPVi, although balloon testing prior to TPVi remains essential.

OBJECTIVE To describe the epidemiology of noninvasive ventilation therapy for patients admitted to pediatric cardiac ICUs and to assess practice variation across hospitals. DESIGN Retrospective cohort study using prospectively collected clinical registry data. SETTING Pediatric Cardiac Critical Care Consortium clinical registry. PATIENTS Patients admitted to cardiac ICUs at PC4 hospitals. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS We analyzed all cardiac ICU encounters that included any respiratory support from October 2013 to December 2015. Noninvasive ventilation therapy included high flow nasal cannula and positive airway pressure support. We compared patient and, when relevant, perioperative characteristics of those receiving noninvasive ventilation to all others. Subgroup analysis was performed on neonates and infants undergoing major cardiovascular surgery. To examine duration of respiratory support, we created a casemix-adjustment model and calculated adjusted mean durations of total respiratory support (mechanical ventilation + noninvasive ventilation), mechanical ventilation, and noninvasive ventilation. We compared adjusted duration of support across hospitals. The cohort included 8,940 encounters from 15 hospitals: 3,950 (44%) received noninvasive ventilation and 72% were neonates and infants. Medical encounters were more likely to include noninvasive ventilation than surgical. In surgical neonates and infants, 2,032 (55%) received postoperative noninvasive ventilation. Neonates, extracardiac anomalies, single ventricle, procedure complexity, preoperative respiratory support, mechanical ventilation duration, and postoperative disease severity were associated with noninvasive ventilation therapy (p < 0.001 for all). Across hospitals, noninvasive ventilation use ranged from 32% to 65%, and adjusted mean noninvasive ventilation duration ranged from 1 to 4 days (3-d observed mean). Duration of total adjusted respiratory support was more strongly correlated with duration of mechanical ventilation compared with noninvasive ventilation (Pearson r = 0.93 vs 0.71, respectively). CONCLUSIONS Noninvasive ventilation use is common in cardiac ICUs, especially in patients admitted for medical conditions, infants, and those undergoing high complexity surgery. We observed wide variation in noninvasive ventilation use across hospitals, though the primary driver of total respiratory support time seems to be duration of mechanical ventilation.