Intervention for Re-Coarctation in the Single Ventricle Reconstruction Trial: Incidence, Risk and Outcomes
Background—Re-coarctation after the Norwood procedure increases risk for mortality. The Single Ventricle Reconstruction (SVR) trial randomized subjects with a single right ventricle undergoing a Norwood procedure to a modified Blalock-Taussig shunt (MBTS) or right ventricle-pulmonary artery shunt (RVPAS). We sought to determine incidence of re-coarctation, risk factors and outcomes in the SVR trial.
Methods and Results—Re-coarctation was defined by intervention, either catheter-based or surgical. Univariate analysis and multivariable Cox proportional hazard models were performed adjusting for center. Of the 549 SVR subjects, 97 (18%) underwent 131 interventions (92 balloon aortoplasty; 39 surgical) for re-coarctation at median age 4.9 months (range: 1.1-10.5). Intervention typically occurred at pre-stage II catheterization (n=71, 54%) or at stage II surgery (n=38, 29%). In multivariable analysis, re-coarctation was associated with the shunt type in place at the end of the Norwood procedure (HR 2.0 for RVPAS vs. MBTS, p=0.02), and Norwood discharge peak echo-Doppler arch gradient (HR 1.07 per 1 mmHg, p<0.01). Subjects with re-coarctation demonstrated comorbidities at pre-stage II evaluation including higher pulmonary arterial pressures (15.4±3.0 vs. 14.5±3.5 mm Hg; p=0.05), higher pulmonary vascular resistance (2.6±1.6 vs. 2.0±1.0 WU x m²; p=0.04) and increased echocardiographic volumes (end-diastolic volume: 126±39 vs. 112±33 ml/BSA1.3; p=0.02). There was no difference in 12-month post-randomization transplant-free survival between those with and without re-coarctation (p=0.14).
Conclusions—Re-coarctation is common after Norwood and contributes to pre-stage II comorbidities. Although with intervention there is no associated increase in 1-year transplant/mortality, further evaluation is warranted to evaluate effects of associated morbidities.
Clinical Trial Registration Information—www.ClinicalTrials.gov. Identifier: NCT00115934.
- Received December 8, 2012.
- Revision received June 7, 2013.
- Accepted July 1, 2013.