Characteristics of Interstage Death After Discharge from Stage I Palliation

Background: Interstage mortality (IM) remains high for patients with single-ventricle congenital heart disease (SVCHD) in the period between Stage 1 Palliation (S1P) and Glenn operation. We sought to characterize IM.

Methods: This was a descriptive analysis of 2184 patients with SVCHD discharged home after S1P from 60 National Pediatric Cardiology Quality Improvement Collaborative sites between 2008 and 2015. Patients underwent S1P with right ventricle-pulmonary artery conduit (RVPAC), modified Blalock-Taussig-Thomas shunt (BTT), or Hybrid; transplants were excluded.

Results: IM occurred in 153 (7%) patients (median gestational age 38 weeks, 54% male, 77% white), at 88 (IQR 60,136) days of life, and 39 (IQR 17,84) days after hospital discharge; 13 (8.6%) occurred ≤ 30 days after S1P. The mortality rate for RVPAC was lower (5.2%; 59/1138) than BTT (9.1%; 65/712) and Hybrid (20.1%; 27/134). More than half of deaths occurred at home (20%) or in the emergency department (33%). The remainder occurred while inpatient at center of S1P (cardiac intensive care unit 36%, inpatient ward 5%) or at a different center (5%). Fussiness and breathing problems were most often cited as harbingers of death; distance to surgical center was the biggest barrier cited to seeking care. Cause of death was unknown in 44% of cases overall; in the subset of patients who underwent post-mortem autopsy, the cause of death remained unknown in 30% of patients, with the most common diagnosis being low cardiac output.

Conclusions: Most IM occurred in the outpatient setting, with non-specific preceding symptoms and unknown cause of death. These data indicate the need for research to identify occult causes of death, including arrhythmia.