Transplant-Free Survival and Interventions at 6 Years in the SVR Trial

Background: In the SVR trial (Single Ventricle Reconstruction), 1-year transplant-free survival was better for the Norwood procedure with right ventricle-to-pulmonary artery shunt (RVPAS) compared with a modified Blalock–Taussig shunt in patients with hypoplastic left heart and related syndromes. At 6 years, we compared transplant-free survival and other outcomes between the groups. Methods: Medical history was collected annually using medical record review, telephone interviews, and the death index. The cohort included 549 patients randomized and treated in the SVR trial. Results: Transplant-free survival for the RVPAS versus modified Blalock–Taussig shunt groups did not differ at 6 years (64% versus 59%, P =0.25) or with all available follow-up of 7.1±1.6 years (log-rank P =0.13). The RVPAS versus modified Blalock–Taussig shunt treatment effect had nonproportional hazards ( P =0.009); the hazard ratio (HR) for death or transplant favored the RVPAS before stage II surgery (HR, 0.66; 95% confidence interval, 0.48–0.92). The effect of shunt type on death or transplant was not statistically significant between stage II to Fontan surgery (HR, 1.36; 95% confidence interval, 0.86–2.17; P =0.17) or after the Fontan procedure (HR, 0.76; 95% confidence interval, 0.33–1.74; P =0.52). By 6 years, patients with RVPAS had a higher incidence of catheter interventions (0.38 versus 0.23/patient-year, P Conclusions: By 6 years, the hazards of death or transplant and catheter interventions were not different between the RVPAS versus modified Blalock–Taussig shunt groups. Children assigned to the RVPAS group had 5% higher transplant-free survival, but the difference did not reach statistical significance, and they required more catheter interventions. Both treatment groups have accrued important complications. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT00115934.