BACKGROUND: Palliation of the single ventricle (SV) circulation is associated with a burden of lifelong complications. Previous studies have identified that the need for a permanent ventricular pacing system (PPMv) may be associated with additional adverse long-term outcomes. OBJECTIVES: The goal of this study was to quantify the attributable risk of PPMv in patients with SV, and to identify modifiable risk factors. METHODS: This international study was sponsored by the Pediatric and Congenital Electrophysiology Society. Centers contributed baseline and longitudinal data for functionally SV patients with PPMv. Enrollment was at implantation. Controls were matched 1:1 to PPMv subjects by ventricular morphology and sex, identified within center, and enrolled at matched age. Primary outcome was transplantation or death. RESULTS: In total, 236 PPMv subjects and 213 matched controls were identified (22 centers, 9 countries). Median age at enrollment was 5.3 years (quartiles: 1.5-13.2 years), follow-up 6.9 years (3.4-11.6 years). Median percent ventricular pacing (Vp) was 90.8% (25th-75th percentile: 4.3%-100%) in the PPMv cohort. Across 213 matched pairs, multivariable HR for death/transplant associated with PPMv was 3.8 (95% CI 1.9-7.6; P < 0.001). Within the PPMv population, higher Vp (HR: 1.009 per %; P = 0.009), higher QRS z-score (HR: 1.19; P = 0.009) and nonapical lead position (HR: 2.17; P = 0.042) were all associated with death/transplantation. CONCLUSIONS: PPMv in patients with SV is associated with increased risk of heart transplantation and death, despite controlling for increased associated morbidity of the PPMv cohort. Increased Vp, higher QRS z-score, and nonapical ventricular lead position are all associated with higher risk of adverse outcome and may be modifiable risk factors.

Cardiology Centre Department of Paediatrics and Adolescent Medicine Hong Kong Children's Hospital Hong Kong SAR China

Children's Heart Centre 2nd Faculty of Medicine Charles University Prague and Motol University Hospital Prague Czech Republic

Children's Heart Centre 2nd Faculty of Medicine Charles University Prague and Motol University Hospital Prague Czech Republic; Pediatric Cardiology Unit Department of Women's and Child's Health University of Padova Padova Italy

Children's Mercy Hospital University of Missouri Kansas City Missouri USA

Department of Cardiology Boston Children's Hospital Boston Massachusetts USA; Department of Pediatrics Harvard Medical School Boston Massachusetts USA

Department of Congenital Heart Diseases and Pediatric Cardiology German Heart Center Munich Munich Germany

Department of Paediatrics University of Tokyo Hospital Tokyo Japan

Department of Pediatric Cardiology Georg August University Medical Center Göttingen Germany

Department of Pediatrics Division of Cardiology Oregon Health and Science University Portland Oregon USA

Department of Pediatrics Division of Pediatric Cardiology University of Alberta Stollery Children's Hospital Edmonton Alberta Canada

Division of Cardiology Children's Hospital Los Angeles Los Angeles California USA; Keck School of Medicine University of Southern California Los Angeles California USA

Division of Cardiology Department of Pediatrics UCLA Health System Los Angeles California USA; Division of Cardiology Department of Medicine Ahmanson UCLA Adult Congenital Heart Disease Center Los Angeles California USA; UCLA Cardiac Arrhythmia Center UCLA Health System Los Angeles California USA

Division of Pediatric Cardiology Department of Pediatrics Stanford University Stanford California USA

Division of Pediatric Cardiology Department of Pediatrics Stanford University Stanford California USA; Division of Pediatric Cardiothoracic Surgery Department of Cardiothoracic Surgery Stanford University Stanford California USA

Division of Pediatric Cardiology Department of Pediatrics UCSF School of Medicine San Francisco California USA

Joe DiMaggio Children's Hospital Hollywood Florida USA

Labatt Family Heart Centre The Hospital for Sick Children University of Toronto Toronto Ontario Canada

Paediatric Cardiology Evelina London Children's Hospital London United Kingdom

Paediatric Cardiology Great Ormond Street London United Kingdom

Primary Children's Hospital University of Utah Salt Lake City Utah USA

Sibley Heart Center Atlanta Georgia USA

The Heart Institute Cincinnati Children's Hospital Medical Center Ohio USA

The Royal Children's Hospital MCRI and University of Melbourne Melbourne Victoria Australia

University of Iowa Healthcare Iowa City Iowa USA

University of Michigan CS Mott Children's Hospital Ann Arbor Michigan USA

J Am Coll Cardiol. 2022 Aug 30;80(9):915-917. doi: 10.1016/j.jacc.2022.05.052 PubMed