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Interstage attrition between bidirectional Glenn and Fontan palliation in children with hypoplastic left heart
Waldemar F Carlo1, Kathleen E Carberry, Jeffrey S Heinle
1Division of Pediatric Cardiology, University of Alabama at Birmingham, Ala, USA. wfcarlo@peds.uab.edu
Insights
Interstage attrition in hypoplastic left heart syndrome (HLHS) is a significant concern. Moderate to severe tricuspid valve regurgitation and lower weight z-scores are key risk factors for interstage death or transplantation.
Area of Science:
- Pediatric Cardiology
- Congenital Heart Disease
- Surgical Outcomes
Background:
- Improving survival rates for staged palliation of hypoplastic left heart syndrome (HLHS) has shifted focus to interstage mortality.
- Interstage death and transplantation represent a growing proportion of mortality in HLHS patients.
Purpose of the Study:
- To identify risk factors for death or cardiac transplantation during the interstage period.
- To analyze the period between the bidirectional Glenn and Fontan procedures in HLHS patients.
Main Methods:
- Retrospective review of HLHS patients who underwent bidirectional Glenn surgery.
- Inclusion of standard-risk patients discharged after Norwood and bidirectional Glenn procedures.
- Statistical analysis using Cox proportional hazard modeling to determine independent risk factors.
Main Results:
- The interstage attrition rate was 12% (95% CI: 1.56-23.24), with 8 deaths and 3 transplants among 92 patients.
- No correlation found between interstage attrition and hemodynamic data, aortic arch obstruction, or right ventricular dysfunction.
- Moderate/severe tricuspid valve regurgitation (HR: 6.02) and lower weight z-score (HR: 0.38) were independent preoperative risk factors.
Conclusions:
- Interstage attrition occurred in 12% of the study population.
- Moderate or greater tricuspid valve regurgitation is a significant risk factor for interstage attrition.
- Low weight z-score at the time of bidirectional Glenn is also an important predictor of interstage attrition.
Objective:
With improving operative mortality for staged palliation of hypoplastic left heart syndrome, interstage death accounts for an increasing proportion of hypoplastic left heart syndrome mortality. We investigated risk factors for death or cardiac transplantation during the interstage period between bidirectional Glenn and Fontan procedures in children with hypoplastic left heart syndrome.
Methods:
Patients with hypoplastic left heart syndrome who underwent bidirectional Glenn between August 1995 and June 2007 were screened. Standard risk patients, defined by having been discharged after both Norwood and bidirectional Glenn, were included for analysis. Patient demographic, echocardiographic, cardiac catheterization, and operative data were reviewed. Interstage attrition was defined as death or cardiac transplantation more than 30 days after bidirectional Glenn and before the Fontan procedure. Statistical analysis was carried out using the Student t test, Pearson chi-square correlation, and Cox proportional hazard modeling for multivariable analysis.
Results:
Ninety-two patients with hypoplastic left heart syndrome were alive at 30 days after bidirectional Glenn. Of these patients, 8 died and 3 underwent cardiac transplantation at a median of 391 days (range, 59-1175 days) after bidirectional Glenn, yielding an interstage attrition rate of 12%. Removing the 7 patients who are still awaiting Fontan (but all of whom are at least 3.5 years after bidirectional Glenn) adjusts the attrition rate to 13%. Interstage attrition did not correlate with hemodynamic data obtained at cardiac catheterization, aortic arch obstruction, or right ventricular dysfunction. Multivariable analysis demonstrated that the presence of moderate or severe tricuspid valve regurgitation (hazard ratio, 6.02; 95% confidence interval, 1.56-23.24; P < .01) and weight z score (hazard ratio, 0.38; 95% confidence interval, 0.16-0.88; P = .02) were independent preoperative risk factors for interstage attrition.
Conclusions:
Interstage attrition between bidirectional Glenn and Fontan procedures occurred in 12% of our study population. Moderate or greater tricuspid valve regurgitation and low weight z score at the time of bidirectional Glenn are important risk factors for interstage attrition between the bidirectional Glenn and Fontan procedures in children with hypoplastic left heart syndrome.
