Arrhythmias After Stage I Hybrid Palliation in Single-Ventricle Patients

Utility of the NEONATE Score at an Institution that Routinely Performs the Hybrid Procedure for Hypoplastic Left Heart Syndrome

NEONATE score > 17 has been proposed as a risk factor for interstage mortality/cardiac transplant (IM/T) for patients with single ventricle physiology. Hybrid procedure is assigned 6 points, the highest possible score for that surgical variable. Most centers reserve the hybrid procedure for high-risk patients. Goal of this study was to evaluate the NEONATE score at a center that routinely performs the hybrid procedure. Retrospective chart review of patients undergoing the hybrid procedure was performed (2008-2021). Demographics and variables used for the NEONATE score were collected. Maximization of Youden's J Statistic used to determine cohort-specific optimal threshold for patients undergoing comprehensive Stage II procedure (H-CSII) versus those with IM/T (H-IM/T). Total of 120 patients met inclusion criteria (H-CSII = 105, H-IM/T = 15). Gestational age was median 39 weeks (IQR 38, 39) and birth weight was 3.18 kg (2.91, 3.57). No patient was discharged with opiates or required post-operative extracorporeal circulatory support. Optimal threshold, as selected by maximizing Youden's J Statistic, was 22. Score > 22 had a positive predictive value of 0.33 (95% CI 0.12-0.62), negative predictive values of 0.90 (95% CI 0.83-0.95), and accuracy of 0.83 (95% CI 0.75-0.90) for IM/T. At a center that routinely performs the hybrid procedure, value of > 22 had the highest accuracy. This suggests that the hybrid procedure is not necessarily intrinsically a risk-factor for IM/T, but rather patient selection for the hybrid procedure may play a larger role at centers that do not routinely perform this procedure.

Association of Digoxin Use With Transplant-Free Interstage Survival in Infants Palliated With a Stage 1 Hybrid Procedure

Background Digoxin prescription in patients with single-ventricle physiology after stage 1 palliation is associated with reduced interstage death. Prior literature has primarily included patients having undergone the Norwood procedure. We sought to determine if digoxin prescription at discharge in infants following hybrid stage 1 palliation was associated with improved transplant-free interstage survival. Methods and Results A retrospective multicenter cohort analysis was conducted using data from the National Pediatric Cardiology Quality Improvement Collaborative registry data from 2008 to 2021. Infants with functional single ventricles and aortic arch obstruction discharged home after the hybrid stage 1 palliation hospitalization were included. Patients were excluded if they had supraventricular tachycardia or conversion to Norwood operation. The primary outcome was transplant-free survival. Multivariable logistic regression analysis including a propensity score for digoxin use identified associations between digoxin use and interstage death or transplant. Of 259 included infants from 45 sites, 158 (61%) had hypoplastic left heart syndrome. Forty-nine percent had a gestational age ≤38 weeks, 18% had a birth weight <2.5 kg, and 58% had a preoperative risk factor. Of the 259 subjects, 129 (50%) were discharged on digoxin. Interstage death or transplant occurred in 30 (23%) patients in the no-digoxin group compared with 18 (14%) in the digoxin group (P=0.06). With multivariate analysis, discharge digoxin prescription was associated with a lower risk of interstage death or transplant (adjusted odds ratio, 0.48 [95% CI, 0.24-0.93]; P=0.03). Conclusions In infants with single-ventricle physiology who underwent hybrid stage 1 palliation, digoxin prescription at hospital discharge was associated with improved interstage transplant-free survival.

Post-operative arrhythmias in patients with hypoplastic left heart syndrome and anatomic variants: incidence, type, and course

BACKGROUND

Arrhythmias are common in the post-operative course of patients with hypoplastic left heart syndrome. We sought to determine the types, incidence, risk factors, and impact of arrhythmias in patients with HLHS and anatomic variants.

METHODS

We performed a retrospective chart review of 120 consecutive patients with HLHS and anatomical variants, who had single-ventricle palliation at our institution from January, 2006 to December, 2016.

RESULTS

A total of thirty-one patients (26%) had 37 episodes of arrhythmias over a median follow-up period of 3.5 years. Of the 37 episodes, 12 (32.4%) were ectopic atrial tachycardia, 9 (24.3%) were paroxysmal supraventricular tachycardia, 4 (10.8%) were junctional ectopic tachycardia, 5 (13.6%) were sinus node dysfunction, 3 (8.1%) were heart block, 2 (5.4%) were atrial flutter, and 2 (5.4%) were ventricular tachycardia. Twenty-four (65%) of the arrhythmias occurred at post-stage 1 surgery. Most (64.8%) of the arrhythmias were resolved. Arrhythmias that occurred at post-stage 1 surgery were more likely to resolve compared to post-stages 2 or 3 (p = 0.006). No anatomical, surgical, or clinical variables were associated with arrhythmia except for age (OR per unit decrease in age at stage 1 palliation: 1.12 (95% CI 1.003, 1.250); p = 0.0439). Arrhythmias were not associated with length of hospital stay or mortality.

CONCLUSION

Arrhythmias are common in patients with HLHS and anatomic variants, with EAT and PSVT being the most common types. Arrhythmias were associated with younger age at surgery, but did not affect mortality or length of hospital stay.

Catheter ablation of orthodromic reciprocating tachycardia and atrioventricular nodal reentrant tachycardia in children with hypoplastic left heart syndrome

INTRODUCTION

Experience with catheter ablation of orthodromic reciprocating tachycardia (ORT) and atrioventricular nodal reentrant tachycardia (AVNRT) in young children with hypoplastic left heart syndrome (HLHS) is limited. We report the feasibility, safety, and outcomes of catheter ablation of ORT and AVNRT in children with HLHS.

METHODS AND RESULTS

This was a retrospective review of patients with HLHS who underwent catheter ablation for reentrant supraventricular tachycardias (excluding atrial tachycardias) between 2005 and 2017 at a single center. Descriptive data including demographics, clinical history, procedural data, and outcomes were recorded. Ten children with HLHS underwent eleven catheter ablation procedures. Median age and weight at ablation were 2.7 years (range: 0.1-10.5) and 11.4 kg (range: 3.6-30.4), respectively. Tachycardia mechanism was AVNRT in four, ORT in five (two with preexcitation), and both in one. Acute procedural success was 100% and there was no spontaneous recurrence of tachycardia orpreexcitationin median 92 months (range: 21-175 months) follow-up. Five patients underwent subsequent EP studies at catheterization (intracardiac) or after surgery (via epicardial wires): three were noninducible, one after AVNRT ablation had inducible atrial tachycardia, and one after initial ORT ablation had inducible ORT at fenestration closure and underwent successful repeat ablation. Thus, long-term freedom from clinical tachycardia was 100% and from inducible AVNRT or ORT was 80%.

CONCLUSION

Transcatheter ablation for ORT and AVNRT in children with HLHS can be performed with excellent acute and long-term success without major complications.