Perioperative mechanical circulatory support in children: an analysis of the Society of Thoracic Surgeons Congenital Heart Surgery Database

Abstract

Objectives: Analyses of mechanical circulatory support (MCS) in pediatric heart surgery have primarily focused on single-center outcomes or narrow applications. We describe the patterns of use, patient characteristics, and MCS-associated outcomes across a large multicenter cohort.

Methods: Patients (aged <18 years) in the Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database (2000-2010) were included. The characteristics and outcomes of those receiving postoperative MCS were described, and bayesian hierarchical models were used to examine variations in the adjusted MCS rates across institutions.

Results: Of 96,596 operations (80 centers), MCS was used in 2.4%. The MCS patients were younger (13 vs 195 days, P < .0001) and more often had STS-defined preoperative risk factors (57.2% vs 32.7%, P < .0001). The operations with the greatest MCS rates included the Norwood procedure (17%) and complex biventricular repairs (arterial switch, ventricular septal defect, and arch repair [14%]). More than one half of the MCS patients did not survive to hospital discharge (53.2% vs 2.9% of non-MCS patients; P < .0001). MCS-associated mortality was greatest for truncus arteriosus and Ross-Konno operations (both 71%). The hospital-level MCS rates adjusted for patient characteristics and case mix varied by 15-fold across institutions, with both high- and low-volume hospitals having substantial variation in MCS rates.

Conclusions: Perioperative MCS use varied widely across centers. The MCS rates were greatest overall for the Norwood procedure and complex biventricular repairs. Although MCS can be a life-saving therapy, more than one half of MCS patients will not survive to hospital discharge, with mortality >70% for some operations. Future studies aimed at better understanding the appropriate indications, optimal timing, and management of MCS could help to reduce the variation in MCS use across hospitals and improve outcomes.

Keywords: 20; 25; 27; ECMO; ELSO; Extracorporeal Life Support Organization; MCS; STS; Society of Thoracic Surgeons; extracorporeal membrane oxygenation; mechanical circulatory support.

Figure 1. Post-operative MCS Rates for Benchmark Procedures and Associated Mortality

MCS=mechanical circulatory support; ASD=atrial septal defect; VSD=ventricular septal defect; BDG/HF=bidirectional Glenn/hemiFontan; TOF=tetralogy of Fallot; CAVC=complete atrioventricular canal; ASO=arterial switch operation; ASO/VSD=arterial switch operation/ventricular septal defect; TA=truncus arteriosus; Nwood=Norwood

Figure 2. Variation in Adjusted MCS Rates Across Hospitals

Adjusted post-operative MCS rates are listed for each hospital (black box represents adjusted estimate and lines indicate 95% confidence intervals). The horizontal dotted line indicates the post-operative MCS rate in the overall cohort.

Figure 3. Relationship of Adjusted MSC Rates with Total Surgical Volume Across Hospitals

Adjusted post-operative MCS rates are listed for each hospital in order of increasing average annual total cardiac surgical volume (black box represents adjusted estimate and lines indicate 95% confidence intervals). The horizontal dotted line indicates the post-operative MCS rate in the overall cohort. Adjusted MCS rates in volume groups are also listed at the bottom of the plot.