Abstract 11328: Transplant-Free Survival, Catheter Interventions, and Events at 3 Years in the Single Ventricle Reconstruction Trial
Background: In the Single Ventricle Reconstruction (SVR) trial, the Norwood procedure with the right ventricle-to-pulmonary artery shunt (RVPAS) had improved 1-year (yr) transplant (tx)-free survival compared to the modified Blalock-Taussig shunt (MBTS). When the last enrolled patient (pt) reached age 3 yrs, we compared shunt groups with respect to death/tx, cardiac catheter (cath) interventions, and medical events/morbidities.
Methods: Vital status and medical history were ascertained by annual record review and phone interviews. Of 549 pts treated, 542 were analyzed, 5 lost to f/u and 2 censored at biventricular repair <3 yrs. Analyses were by intention-to-treat.
Results: The death/tx rates for the RVPAS vs. MBTS groups at 3 yrs were 33% vs. 39% (P=.14). The shunt groups also did not differ using Kaplan-Meier analysis with all available f/u data (4.4±1.0 yrs, log rank P=.11). Eight deaths/tx occurred after 1 yr of age (5 RVPAS, 3 MBTS). The shunt groups had similar survival/tx rates conditional on survival to 1 yr. The rates of Fontan completion, medical events and comorbidities were similar in the 2 shunt groups. However by 3 yrs, RVPAS pts had higher incidence rates (number/pt/yr) for interventional cath lab visits and cath interventions (both P<.001), as well as for specific types of cath intervention (Table). The RVPAS vs. MBTS hazard ratio (HR) for any cath intervention increased over time (P=0.003): <5 mo HR= 0.74 (95% CI, 0.52-1.05); 5 mo-1 yr HR=1.50 (0.77-2.93), and >1 yr HR=2.42 (1.25, 4.70). The effect of shunt type on cath intervention was not explained by center differences.
Conclusion: In contrast to 1-yr outcomes, at 3 yrs, children randomized to a Norwood procedure with RVPAS no longer had significantly better tx-free survival compared to MBTS, but they had almost twice the incidence of cath interventions, with an increasing HR for a cath intervention over time. Ongoing follow-up will delineate the evolving natural history after Norwood with RVPAS vs. MBTS.
- © 2012 by American Heart Association, Inc.